ACS Publications. Most Trusted. Most Cited. Most Read
Quick View

OR SEARCH CITATIONS

My Activity
Publications
CONTENT TYPES

Figure 1Loading Img
Download Hi-Res ImageDownload to MS-PowerPointCite This:J. Agric. Food Chem. 2019, 67, 39, 10921-10929
RETURN TO ISSUEPREVArticleNEXT

Melanoidins from Coffee, Cocoa, and Bread Are Able to Scavenge α-Dicarbonyl Compounds under Simulated Physiological Conditions

  • Hao Zhang
    Hao Zhang
    School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
    Food Quality & Design Group, Wageningen University & Research, Wageningen NL-6708 WG, Netherlands
    More by Hao Zhang
  • , 
  • Hui Zhang
    Hui Zhang
    School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
    More by Hui Zhang
    Orcidhttp://orcid.org/0000-0002-0756-9334
  • , 
  • Antonio Dario Troise
    Antonio Dario Troise
    Department of Agricultural Sciences, University of Naples ‘‘Federico II’’, 80055 Portici, Italy
    More by Antonio Dario Troise
  • , and 
  • Vincenzo Fogliano*
    Vincenzo Fogliano
    Food Quality & Design Group, Wageningen University & Research, Wageningen NL-6708 WG, Netherlands
    *E-mail: [email protected]. Phone: +31 317485171.
    More by Vincenzo Fogliano
    Orcidhttp://orcid.org/0000-0001-8786-9355
Cite this: J. Agric. Food Chem. 2019, 67, 39, 10921–10929
Publication Date (Web):September 8, 2019
https://doi.org/10.1021/acs.jafc.9b03744

Copyright © 2022 American Chemical Society. This publication is licensed under CC-BY-NC-ND.

  • Open Access

Article Views

3911

Altmetric

-

Citations

30
LEARN ABOUT THESE METRICS
PDF (1 MB)
Get e-Alerts
Supporting Info (1)»
SUBJECTS:

Abstract

High Resolution Image
Download MS PowerPoint Slide

Free amino residues react with α-dicarbonyl compounds (DCs) contributing to the formation of advanced glycation end products (AGEs). Phenolic compounds can scavenge DCs, thus controlling the dietary carbonyl load. This study showed that high-molecular weight cocoa melanoidins (HMW-COM), HMW bread melanoidins (HMW-BM), and especially HMW coffee melanoidins (HMW-CM) are effective DC scavengers. HMW-CM (1 mg/mL) scavenged more than 40% DCs within 2 h under simulated physiological conditions, suggesting some physiological relevance. Partial acid hydrolysis of HMW-CM decreased the dicarbonyl trapping capacity, demonstrating that the ability to react with glyoxal, methylglyoxal (MGO), and diacetyl was mainly because of polyphenols bound to macromolecules. Caffeic acid (CA) and 3-caffeoylquinic acid showed a DC-scavenging kinetic profile similar to that of HMW-CM, while mass spectrometry data confirmed that hydroxyalkylation and aromatic substitution reactions led to the formation of a stable adduct between CA and MGO. These findings corroborated the idea that antioxidant-rich indigestible materials could limit carbonyl stress and AGE formation across the gastrointestinal tract.

KEYWORDS:

Introduction

ARTICLE SECTIONS
Jump To
Reactive α-dicarbonyl compounds (DCs) are formed during Maillard-induced carbohydrate degradation. Glyoxal (GO), methylglyoxal (MGO), diacetyl (DA), and 3-deoxyglucosone are the most extensively characterized markers, and they are key precursors of advanced glycation end products (AGEs). (1−3) DCs can be formed also in vivo where they can contribute to the development of chronic diseases, oxidative and inflammatory cascades and to the formation of endogenous AGEs. (4,5) In addition, DCs may influence normal physiological functions through carbonylation of lipids, proteins, or DNAs. (6) While for dietary AGEs a cause–effect relationship with health outcomes is still a hypothesis, DCs generated during glycolysis are involved in the pathogenesis of diabetic complications including obesity, nephropathy, and neuropathy, (7,8) and their excessive production was demonstrated in diabetes. (9)
Dicarbonyl trapping has been proposed as an effective strategy to control undesired outcomes in foods and to prevent further complications in vivo. (10) Several natural foods and their extracts inhibit dicarbonyl-induced reactions by their antioxidant activity and by reducing GO and MGO concentration. Effective examples in foods include tea catechins, ginger shogaols, (11) secoiridoid derivatives in olive leaf and oil, (12) and hydroxycinnamic acid derivatives, (13) while creatine can scavenge reactive DCs in meat products (14) and in vivo. (15) A major role in scavenging in vivo formation of DCs is played by glyoxalase, an ubiquitous enzyme connected with glycolysis. (16)
There is no consensus on the correlation between dietary intake of DCs and their in vivo concentrations. A correlation between endogenous MGO and a DC-rich diet has been recently proposed; however, it cannot be ruled out that the correlation is driven by many confounding factors such as lipid and protein concentrations in the diet. (17,18)
The hypothesis that reducing the dietary intake of DCs or scavenging them within the gastrointestinal tract could reduce the endogenous DC concentration is interesting (4) and can be of particular relevance in pathological conditions. Treatment with dietary flavonoids was effective in promoting a significant decrease in the level of DCs in the human body. (19)
Melanoidins, high-molecular weight brown polymers present in foods, are a bioactive source of reducing power combining reductones and condensed phenolic compounds with antioxidant, antimicrobial, and prebiotic capacities. (20,21) Melanoidins act as a functional dietary fiber, favoring the delivery of reducing capacity along the gastrointestinal tract. (22) As melanoidins are formed during food processing, their structure and composition change with the food; the principal constituents of coffee and cocoa melanoidins are polysaccharides; in bread, melanoidins are formed by gluten proteins and starch cross-linked by Maillard reaction products. (22) In coffee, cocoa, nuts, and fruits, besides carbohydrates and proteins, phenolic compounds can be incorporated into melanoidin structures. Fragments of chlorogenic acids (CGAs) have been found in coffee melanoidins, (23) and cocoa melanoidins contain polyphenols such as epicatechins. (24) Fogliano and Morales (25) estimated that the dietary intake of melanoidins from all of the possible sources could be close to 10.0 g per average consumer. Therefore, their role as DC scavengers can have a physiological relevance modulating the amount of dietary DCs inside the gut lumen and their bioavailability.
In this study, high molecular weight melanoidins from cocoa, coffee and bread were selected as they represent phenolic-rich (coffee and cocoa) and nonphenolic-rich (bread) melanoidins. We aimed at comparing the dicarbonyl trapping capacity of these different melanoidins sources in an in vitro model system in order to elucidate possible mechanisms behind the trapping process and to explore the possibility of using melanoidins as a bioactive source of reducing compounds.

Materials and Methods

ARTICLE SECTIONS
Jump To

Chemicals and Melanoidin Sources

GO aqueous solution (GO, 40%), MGO aqueous solution (MGO, 40%), DA, quinoxaline (QX), 2-methylquinoxaline (2-MQX), 2,3-dimethylquinoxaline (2,3-MQX), pyridoxamine (PM) dihydrochloride , diethylenetriaminepentacetic acid (DETAPAC), o-phenylenediamine (OPD), ethylenediaminetetracetic acid (EDTA), 3-caffeoylquinic acid (3-CQA), caffeic acid (CA), ferulic acid (FA), and Pronase E were purchased from Sigma-Aldrich (St. Louis, MO). Hydrochloric acid (37%), sodium hydroxide, disodium hydrogen phosphate dihydrate, sodium dihydrogen phosphate dihydrate, and acetic acid were obtained from Merck (Darmstadt, Germany). Dried cocoa beans (Forastero) were provided by CACEP (Villahermosa, Mexico). Dark roasted arabica coffee beans and bread crumbs were purchased from a local supermarket.

Preparation of High Molecular Weight Coffee Melanoidins (HMW-CM)

Extraction of HMW-CM followed the procedure described by Nunes and Coimbra (26) with some modifications. Coffee beans were ground to an average particle size of 0.4 mm. Lipids were removed by using dichloromethane (1:30, w/v, three times), and 100 g of coffee powder was extracted using 1200 mL of water at 80 °C for 20 min, and then filtered through a filter paper (Whatman 595, Billerica, MA) under vacuum. The filtrate was dialyzed (MW cutoff 14 kDa, D9402, Sigma-Aldrich) at 4 °C with 10 water renewals (1200 mL for each cycle). After dialysis, the retentate was freeze-dried to obtain HMW-CM.

Preparation of High Molecular Weight Cocoa Melanoidins (HMW-COM)

HMW-COM was obtained from toasted cocoa beans according to the methods described by Summa et al. (27) In brief, 200 g of deshelled cocoa beans was roasted using a convection oven (150 °C, 210 min, Memmert, Schwabach, Germany) and cryogenically ground to a fine powder by a cryogenic grinder (6875D Freezer/Mill, SPEX SamplePrep, UK). Cocoa powder was defatted with petroleum ether at 30 °C for 1.5 h and centrifuged at 3000g for 15 min at 4 °C. The supernatant was discarded, and the process was repeated three times. After air-drying overnight, the defatted cocoa powder (50 g) was extracted with 500 mL of water at 80 °C for 20 min. Then, the aqueous solution was centrifuged at 5000g for 10 min, and the supernatant was filtered through a filter paper (Whatman 595) to remove the insoluble materials. The filtrate (400 mL) was dialyzed using a dialysis membrane (MW cutoff 14 kDa) for 3 days with eight water renewals until conductivity reached a value lower than 2 μS/cm detected by a conductivity meter (WTW inoLab Cond 7110, Fisher Scientific, Sweden). After storage at −20 °C, the retentate was lyophilized to yield HMW-COM. All freeze-dried HMW-COM samples were kept at −20 °C.

Preparation of High Molecular Weight Bread Melanoidins (HMW-BM)

Before preparing HMW-BM as described by Borrelli et al., (28) bread crumbs were heated at 200 °C for 15 min to generate enough bread melanoidins. After milling and sieving to a particle size of 0.15 mm, 50 g of bread powder was mixed with 600 mL of 0.2 M Tris-HCl buffer (pH 8.0) containing 0.7 U/mL of Pronase E and digested at 37 °C for 72 h. After centrifugation (4000g, 4 °C, 15 min), the supernatant was filtered through a Whatman 595 filter paper and dialyzed (MW cutoff 14 kDa) against 4 L of distilled water at 4 °C for 4 days with 10 water renewals. The collected retentate was freeze-dried and kept at −20 °C until used.

Evaluation of the Direct Dicarbonyl Trapping Capacity

Direct GO, MGO, and DA trapping capacities were determined using the method described by Glomb and Tschirnich (29) with some modifications. GO (0.37 mg/mL), MGO (0.46 mg/mL), DA (0.55 mg/mL), PM (1.08 mg/mL), CA (1.15 mg/mL), and 3-CQA (2.27 mg/mL) were separately dissolved in phosphate buffer (0.1 mol/L, pH 7.4) in order to obtain the same molarity (6.4 mmol/L). QX and 2,3-MQX (10 mmol/L) were dissolved in 20% aqueous methanol separately. GO, MGO, or DA (100 μL) was mixed with 750 μL of phosphate buffer and 100 μL of either phosphate buffer (blank), PM solution (positive control), or melanoidin solutions (0.1–25 mg/mL) and then incubated at 37 °C up to 168 h. Melanoidin solutions were prepared in the range of 0.01–2.5 mg/mL in model systems, while the final concentration of PM and DCs was 0.64 mmol/L. Additionally, in order to monitor the kinetic profile of DCs scavenged by HMW-CM and its predominant phenolic acids, 750 μL of phosphate buffer, 100 μL of one of the DCs, and 100 μL HMW-CM (20 mg/mL) or phenolic acids mentioned above were incubated at 37 °C for 2, 4, 24, 48, 120, and 168 h. All of the incubated samples were mixed with 200 μL of 0.2% OPD solution containing DETAPAC (9.6 mM) and 50 μL of 2,3-MQX (in reaction system with GO) or QX (in reaction system with MGO and DA) as the internal standard; all solutions were vortexed for 5 s. The mixture was kept at 37 °C in the dark for 2 h and filtered using a 0.22 μm polyvinylidene fluoride (PVDF) filter before high-performance liquid chromatography analysis. To evaluate the physiological relevance of dicarbonyl scavenging ability of HMW-CM and HMW-COM, the estimated dietary intake of coffee melanoidins (1.0 g/person per day) (25) and MGO (1.9 mg/person per day) (30) was reacted within an assumed digestive volume of the 1 L mimicking upper intestinal phase. In brief, 1.0 mg/mL of HMW-CM or HMW-COM and 0.026 mmol/L of GO, MGO, or DA were incubated together at 37 °C (pH 7.4) up to 2 h. Then, incubated mixtures were derivatized using OPD as described above and subsequently subjected to liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis.

Determination of QX Derivatives

Liquid Chromatography UV

Determination of three QX derivatives was performed on a Thermo Ultimate 3000 ultrahigh-pressure liquid chromatography system coupled with an RS 3000 diode array detector (DAD, Thermo Fisher Bremen, Germany). A Kinetex EVO C18 column (150 mm × 2.1 mm, 2.6 μm; Phenomenex, Aschaffenburg, Germany) equipped with a security guard of the same stationary phase was used. Separation was achieved through a gradient mixture of (A) 0.1% formic acid in water and (B) 0.1% formic acid in methanol at a flow rate of 0.4 mL/min, while the column was thermostated at 40 °C. The eluant program was as follows: 0–2 min, 2% B; 2–8 min, 2–25% B; 8–10 min, 25–50% B; 10–13 min, 50–95% B; 13–14 min, 95–2% B; and 14–17 min, 2% B. Chromatograms were recorded at 315 nm, and the retention times of QX, 2-MQX, and 2,3-MQX were 9.12, 11.13, and 12.03 min, respectively.

Liquid Chromatography–Tandem Mass Spectrometry

Determination of QXs formed during the simulated upper intestinal phase was conducted under the same chromatographic and UV conditions described above but with a TSQ triple quadrupole mass spectrometer as the detector (Thermo Fisher Scientific, Bremen, Germany). Positive electrospray ionization was used for detection, and the electrospray source parameters were set as follows: spray voltage 4.0 kV; capillary temperature 350 °C; dwell time 100 ms; sheath gas and aux gas were set to 10.0 and 5.0 AU (arbitrary unit). The QX derivatives of GO, MGO, and DA were identified by the selected reaction monitoring mode using the following transitions (in parenthesis collision energy, CE): GOqx: m/z 131 → 77 (CE: 25 V); MGOqx: m/z 145 → 77 (CE: 28 V) and DAqxm/z 159 → 77 (CE: 32 V).

Quantification

The amount of unreacted GO, MGO, and DA in different samples was calculated through the ratio of peak area of QX, 2-MQX, 2,3-MQX, and their corresponding internal standard, respectively. Calibration curves were in the concentration range of 2.0–100.0 ppm for UHPLC analysis and 0.02–5.0 ppm for UHPLC–MS/MS analysis, with linearity higher than 0.99 for all the investigated compounds in both conditions. Percentage decrease in each DC was calculated using the following equation (eq 1)
(1)

Release of Bound Phenolic Acids from HMW-CM

Adsorbed Phenolic Compounds

Noncovalently bound phenolic compounds were released according to the method reported by Delgado-Andrade and Morales (31) with few modifications. Briefly, 45 mg of HWM-CM was incubated in 5.095 mL of NaCl solution (2 M) overnight at 4 °C. Then, the extracts were centrifuged (4000g, 4 °C, 10 min), and the clear supernatant was filtered through a 0.22 μm PVDF filter to give saline-treated HWM-CM.

Acidic Hydrolysis

Bound phenolic compounds were extracted using acidic hydrolysis of HMW-CM as described by Oracz et al. (32) with some modifications. HMW-CM (3 mL, 15 mg/mL) in 50% aqueous methanol was mixed with 1 mL of HCl (10.2 M) and placed in a heating block at 75 °C for 150 min. After hydrolysis, the solution was neutralized with 1095 μL of 10 M NaOH resulting in a final volume of 5095 μL and centrifuged at 4000g and 4 °C for 10 min. The clear supernatant was filtered using a 0.22 μm PVDF filter to give acid-hydrolyzed HMW-CM. Another 45 mg of HMW-CM was dissolved in 5095 μL of water and centrifuged (4000g, 4 °C, 10 min), and then the supernatant was filtered through a 0.22 μm PVDF filter as nontreated HMW-CM.

Alkaline Hydrolysis

Covalently bound phenolic compounds were released by alkaline hydrolysis of HMW-CM using the method described by Coelho et al. (33) with some modifications. Briefly, 45 mg of HMW-CM was dissolved in 3 mL of 2 M NaOH solution containing 20 mM EDTA. After incubation at 30 °C for 90 min, the mixture was adjusted to pH 7.0 with 950 μL of 6 M HCl, and 1145 μL of water was added to achieve a 5095 μL of final volume. The solution was centrifuged (4000g, 4 °C, 10 min), and the resulting supernatant was filtered with a 0.22 μm PVDF filter to give alkali-hydrolyzed HMW-CM.
The obtained nontreated, saline-treated, acid- and alkali-hydrolyzed HMW-CM were directly subjected to analysis of predominant phenolic acids and evaluation of the dicarbonyl trapping capacity.

Analysis of Predominant Phenolic Acids

Predominant phenolic acids in saline-treated, acid- and alkali-hydrolyzed HMW-CM were analyzed by LC–DAD on a Kinetex EVO C18 column (150 mm × 2.1 mm, 2.6 μm, Phenomenex) equipped with a security guard of the same stationary phase. Eluant A was 0.1% formic acid aqueous solution, and eluant B was 0.1% formic acid in acetonitrile. The gradient was as follows: 0–5 min, 2% B; 5–15 min, 2–17% B; 15–30 min, 17% B; 30–50 min, 17–50% B; 50–70 min, 50–90% B; 70–71 min, 90–2% B; and 71–75, 2% B. The flow rate was 0.4 mL/min. and the column oven was set at 35 °C. Detection was performed at 325 nm, while the chromatographic stream was continuously monitored from 200 to 600 nm. The identification of CA, 3-CQA, and FA was conducted through comparison of their retention times and UV–vis spectra with that of pure CA, 3-CQA, and FA standards under the same chromatographic conditions. 4-caffeoylquinic acid and 5-caffeoylquinic acid were tentatively identified by comparison of their retention times and UV–vis spectra according to Fernandez-Gomez et al. (34) Total CQAs were quantified by the external standard technique using a 3-CQA calibration curve, while CA and FA were quantified by using their respective standards.

Analysis of the Adducts in the MGO–CA Model System by LC–MS/MS

CA (5 mM in 100 mM phosphate buffer, pH 7.4) was incubated alone or with MGO (5 mM in 100 mM phosphate buffer, pH 7.4) for 72 h at 37 °C to give the CA or CA–MGO model system, and then the incubated samples were subjected to UHPLC–MS/MS analysis. Chromatographic separation was performed using a Kinetex EVO C18 column (150 mm × 2.1 mm, 2.6 μm) at 30 °C. The mobile phase consisted of 0.1% formic acid in water (mobile phase A) and 0.1% formic acid in methanol (mobile phase B) at a flow rate of 0.4 mL/min using the following gradients: 0–5 min, 2% B; 5–15 min, 2–17% B; 15–25 min, 17–100% B, and 25–30 min held at 100% B for 5 min, and then the column was re-equilibrated with 2% B for 5 min. The ion source was operated in the negative electrospray ionization mode with the spray voltage at 3.0 kV. Sheath and auxiliary nitrogen gas were used at a flow rate of 50 and 25 AU, respectively. A preliminary trial identified molecular ions of the possible DC-hydroxycinnamic derivative adducts; the selected ion monitoring mode was used in three different channels: m/z 179 for CA, m/z 251 for mono-MGO–CA and m/z 323 for di-MGO–CA. Structural information on CA and the major MGO adducts of CA was obtained by tandem mass spectrometry through collision-induced dissociation with 30 eV collision energy. The mass range was measured from m/z 50 to 350, and data were acquired with Xcalibur version 4.0 (Thermo Fisher).

Statistical Analysis

All experiments were performed in triplicate unless otherwise stated. Significant differences (p < 0.05) in the dicarbonyl trapping capacity of samples were analyzed by Tukey’s HSD test using the SPSS statistics (v. 23.0, IBM, Armonk, NY). The error bar in all figures correspond to the standard deviation (SD).

Results and Discussion

ARTICLE SECTIONS
Jump To

Evaluation of the Direct Dicarbonyl Trapping Capacity of HMW-CM, HMW-COM, and HMW-BM and Their Physiological Relevance

HMW-CM, HWM-COM, and HMW-BM dicarbonyl trapping capacities are reported in Figure 1. All three DCs were effectively scavenged by both HMW-CM and HMW-COM when the concentration of melanoidins is higher than 0.5 mg/mL. HMW-CM showed 68.0, 76.9, and 64.8% trapping capacities for GO, MGO, and DA, respectively, at a concentration of 1 mg/mL. Similarly, HMW-COM was more effective in scavenging GO and MGO while less efficient in scavenging DA than HMW-CM. Considering nonphenolic-rich melanoidins, only MGO (38.1%) was quenched by the highest concentration of HMW-BM, revealing that polysaccharides and protein-based melanoidins have a specific chemical nature able to block MGO, while phenolic compounds in HMW-CM and HMW-COM contribute to the elimination of a wider spectrum of DCs. None of the three DCs was detected after 7 days incubation of three melanoidins (2.5 mg/mL), indicating that melanoidins were not able to release DCs in physiological conditions (data not shown).

Figure 1

Figure 1. GO, MGO, and DA trapping capacities of HMW-CM, HMW-COM, and HMW-BM with different concentrations (0.01–2.5 mg/mL) and PM (0.108 mg/mL) at 168 h. Results are expressed as mean ± SD for n = 3. Bars with the same letter are not significantly different according to Tukey’s HSD test at p > 0.05.

High Resolution Image
Download MS PowerPoint Slide
PM was used to compare melanoidins activity to a well-known carbonyl scavenger. The concentration of HMW-CM and HMW-COM was higher than that of PM (0.108 mg/mL) used in model systems; however, both were more effective than PM in quenching DCs considering differences in their molecular weight. PM exhibited a specific trapping capacity; it was an efficient MGO scavenger, an intermediate DA scavenger, and a weak GO scavenger. This result was in line with previous studies, where MGO was found to be the most efficient α-DCs in reacting with amino residues and in particular with PM because of its ability to form stable heterocyclic compounds. (35,36)
To investigate the physiological relevance of DC trapping capacity by coffee and cocoa melanoidins, they should be tested at a concentration compatible with the daily intake of melanoidins which is in the range 0.5–2.0 g for moderate and heavy consumers. (25) Data summarized in Figure 2 showed that around 40% of GO and MGO were scavenged within 2 h by HMW-CM and HMW-COM, respectively, and for DA, HMW-CM showed a significantly higher efficacy than the other one, reaching about 60%, which is in line with the results presented in Figure 1. A concentration of coffee melanoidins fluctuating between 0.25 and 1 mg/mL in the colon was assayed, assuming that the colon accumulates coffee melanoidins over at least 24 h in a maximum volume of about 2 L. (37) These values showed that melanoidins were effective in trapping DCs not only in the intestinal phase within 2 h but also in the colon to exert further scavenging activity in combination with the microbial population. (38) This evidence suggested that a regular intake of HMW-CM from coffee brew could be effective in controlling carbonyl loading in human bodies.

Figure 2

Figure 2. Dicarbonyl trapping capacity of HMW-CM (1.0 mg/mL), HMW-COM (1.0 mg/mL), and PM (0.108 mg/mL) within 2 h under simulated physiological conditions. The concentration of DCs and melanoidins was calculated according to the estimated daily intake. Results are expressed as mean ± SD for n = 3. Bars with the same letter are not significantly different according to Tukey’s HSD test at p > 0.05.

High Resolution Image
Download MS PowerPoint Slide

Time-Course Evaluation for the HMW-CM Dicarbonyl Trapping Capacity

HMW-CM and its predominant phenolic acid, 3-CQA, and CA were subjected to a time-course investigation in order to gain insights into the reaction between DCs and phenolic compounds in melanoidins. As shown in Figure 3, the GO concentration was reduced by CA up to 11.8% within the first 4 h, while HMW-CM diminished MGO and DA down to 11.8 and 10.2%, respectively. HMW-CM was a better MGO scavenger (50% reduction within 18 h) than GO and DA (50% reduction in about 40 h) upon longer incubation time. HMW-CM at a concentration of 2 mg/mL was characterized by a similar DC trapping capacity toward 0.115 mg/mL of CA (0.64 mmol/L), while its activity was significantly higher than 0.227 mg/mL of 3-CQA (0.64 mmol/L). The amounts of DCs scavenged by 3-CQA increased continuously during incubation, reaching 82.2, 87.6, and 100% for GO, MGO, and DA, respectively, after 168 h, following the same trend of HMW-CM and CA. MGO reduction was in line with Mesías and co-workers, (39) although in other conditions higher values have been reported by Yoon, (40) probably because of the higher concentration of 3-CQA.

Figure 3

Figure 3. Time-course of GO (A), MGO (B), and DA (C) trapping capacity of PM (0.108 mg/mL), HWM-CM (2 mg/mL), CA (0.115 mg/mL), and 3-CQA (0.227 mg/mL). Results are expressed as mean ± SD for n = 3.

High Resolution Image
Download MS PowerPoint Slide
Moreira et al. (41) pointed out that CGA and CGA derivatives are the most abundant phenolic compounds in HMW-CM, and the amount of phenolic compounds incorporated in HMW-CM ranged from 76.5 to 224.0 mg/g (in equivalent weight of CA and CGA). (33) According to these values, bound phenolic compounds in melanoidins were at the same level with the concentration of CA and 3-CQA used in the model system. Altogether, these results supported the hypothesis that CGAs and CA extensively contributed to the overall dicarbonyl trapping capacity of HMW-CM.

Influence of Hydrolysis on the Dicarbonyl Trapping Capacity of HMW-CM

A deeper examination of the relationship between the bound phenolic compounds and dicarbonyl trapping capacity of HMW-CM was achieved through a partial cleavage of the HMW-CM structure. Two hydrolysis methods were used in order to understand the role of melanoidins in scavenging DCs. It was found that 3-CQA, 5-caffeoylquinnic acid, and 4-caffeoylquinnic acid were identified as the most abundantly released phenolic compounds in saline-treated HMW-CM as shown in Figure S1B. Table 1 outlined that the content of absorbed CQAs (298.7 mg/100 g HMW-CM) was in the same order of magnitude as previous studies, (33) although the relative proportion of each CQA was characterized by slight differences probably because of isomerization occurring during roasting and dialysis. (34,42)
Table 1. Content (mg/100 g HWM-CM)a of Released Phenolic Acids from HMW-CM after Different Treatments
 saline treatmentacidic hydrolysisalkaline hydrolysis
total CQAs298.7 ± 6.3ndnd
CAnd65.5 ± 1.7671.1 ± 21.5
FAnd34.7 ± 5.595.7 ± 3.6
a

All values are shown as means ± SD (n = 3). nd, not detected.

A significant amount of phenolic compounds was detected upon acidic and alkaline hydrolysis, especially CA (65.5 and 671.1 mg/100 g HMW-CM) and FA (34.7 and 95.7 mg/100 g HMW-CM) as shown in Table 1. The amount and nature of phenolic compounds bound in coffee melanoidins were previously investigated by releasing ester-linked, condensed, and glycosidically linked phenolic compounds through alkaline saponification, alkaline fusion, and acidic hydrolysis, respectively. (43,44) Our results are in line with previous studies, (33,45) where high amounts of CA and FA were detected in coffee brew or in high-molecular weight melanoidins after using alkaline hydrolysis, highlighting that most of the phenolic compounds in coffee melanoidins are covalently bound to the polysaccharide skeleton. In contrast, the content of CA and FA released after acidic hydrolysis was lower than that of the one reported by Moreira and co-workers, (43) probably because of the differences in the hydrolysis time.
In Figure 4, the total dicarbonyl scavenging activity of HMW-CM before and after saline and hydrolytic treatments was highlighted: the total amount of reactive carbonyls scavenged in the nontreated and saline-treated HMW-CM groups was similar, both significantly higher than that in alkali- and acid-hydrolyzed HMW-CM groups. The acid-hydrolyzed HMW-CM exhibited the lowest amount of free phenolic compounds and blocked 53.7, 63.2, and 46.3% of GO, MGO, and DA, respectively, resulting to be more effective than alkaline-saponified HMW-CM. According to our preliminary trials, ascorbic acid was not added as it could react with DCs, leading to an overestimation of the result (data not shown). The loss of total dicarbonyl trapping capacity in alkali- and acid-hydrolyzed HMW-CM, therefore, is probably due to the oxidation of phenolic acids during hydrolysis. In addition, DC scavenging contributed by free phenolic compounds was estimated according to their content and concentration–response relationship shown in Figure S2. We observed that the DC trapping capacity of coffee melanoidins was mainly associated to the bound phenolic acids, especially CGAs and CA, as the amount of free phenolic acids in nontreated HMW-CM was not sufficient to scavenge DCs, as presented in Figure 4. It was also found that most of the dicarbonyl trapping capacity was still related to the bound phenolic compounds after hydrolysis, while the proportion of DCs scavenged by bound phenolic compounds decreased with the release of free phenolic acids. Previous studies reported that phenolic compounds in coffee melanoidins are mainly in the condensed form, which can be released by alkaline fusion but not hydrolysis, (33) and acidic hydrolysis is not an adequate technique to release bound coffee phenolic compounds compared to alkaline saponification, keeping most of the melanoidins intact, (45) which is in agreement with our results. The interplay between bound phenolic compounds and complex macromolecular structures, as polysaccharides or polypeptides, could act as a “dicarbonyl sponge” following chemical mechanisms previously depicted for antioxidant activity in insoluble polymerized materials. (46) According to the concept of the “antioxidant dietary fiber”, (47) here, we demonstrated that melanoidin-bound polyphenols are able to quench DC compounds, thus contributing to the control of carbonyl stress.

Figure 4

Figure 4. GO, MGO, and DA trapping capacities of nontreated, saline-treated, acidic- and alkaline-hydrolyzed HMW-CM after 168 h incubation. Results are expressed as mean ± SD for n = 3. Different letters indicate significant differences according to Tukey’s HSD test at p > 0.05.

High Resolution Image
Download MS PowerPoint Slide
The ability of bound polyphenols to scavenge DCs paralleled previous reports on antioxidant activity of roasted coffee: the higher the degree of roasting, the more pronounced is the redox potential. (48) Besides pioneering studies on antioxidant activity of coffee melanoidins in vitro, (49,50) direct confirmation of the mechanisms can be inferred from the behavior of coffee melanoidins in vivo. Dittrich and co-workers (51) demonstrated that a melanoidin-rich diet promoted the oxidative stability of LDL up to 35%, suggesting that the bound undigested antioxidants can play an active role. Coelho et al. (33) reported that the association of the condensed phenolic structure with indigestible polysaccharides present in HMW-CM probably is one of the reasons for the observed relationship between coffee consumption and the antioxidant activity of feces.

Studying the Formation of MGO Adducts of CA under Simulated Physiological Conditions by LC–MS/MS.

We hypothesized that the CA moiety in the coffee melanoidin skeleton was mainly responsible for the dicarbonyl trapping capacity. MGO was incubated with CA to investigate the potential formation of carbonyl adducts. Figure 5A–D presented the total ion chromatograms of the model system with CA and CA–MGO, and the extracted ions of the new peaks formed during the incubation. After 3 days, CA decreased by nearly 48.7%, and two new peaks were annotated upon comparison with control without MGO. The peak belonging to CA appeared at 13.82 min with the molecular ion m/z 179 [M–H]−, and the two new peaks at 15.07 and 15.69 min had molecular ion m/z 251 [M – H]− (mono-MGO–CA adduct, mass shift +72 m/z) and m/z 323 [M – H]− (di-MGO–CA adduct, mass shift +144 m/z), respectively, suggesting that these two molecular ions were mono-MGO- and di-MGO-conjugated CA.

Figure 5

Figure 5. Total ion chromatogram of the CA (A) and CA–MGO (B) systems after incubation at 37 °C for 3 days, extracted ion chromatogram [M – H]− of mono-MGO–CA adduct [m/z, 251, (C)] and di-MGO–CA adduct [m/z, 323, (D)], and MS/MS spectra of CA (E), mono-MGO–CA adduct (F), and di-MGO–CA adduct (G).

High Resolution Image
Download MS PowerPoint Slide
Structural information of CA and its MGO adducts was obtained through MS/MS spectra. As shown in Figure 5E–G, the major fragment ions of CA were m/z 135 [M – 44 – H]− and m/z 134 [M – 45 – H]−, which are in line with the typical fragmentation pattern of CA. (52) Fragment ions with m/z 207 [M – 44 – H]− and m/z 135 [M – 44–72 – H]− from the mono-MGO–CA adduct could match with the decarboxylation of CA and subsequent loss of the MGO moiety. Major fragments at m/z 205 and m/z 190 could be obtained by cyclization followed by α-cleavage in the MGO moiety as highlighted in Figure S3 panel B. In MS/MS spectra of di-MGO–CA, fragment ions at m/z 277, m/z 251, and m/z 207 indicated the structure of mono-MGO–CA with the same fragmentation profile. This result suggested that MGO could be attached to unsubstituted carbons in the benzene ring of CA, following a similar reaction scheme as proposed for carbonyl trapping reactions of epicatechins and olive phenols. (12,53)
We hypothesized that also in physiological conditions, the reaction mechanism between CA and MGO can lead to the formation of two isomers as depicted in Figure 6. Several studies suggested that phenolic compounds undergo electrophilic aromatic substitution reactions with GO or MGO at physiological conditions, with the hydroxy group in the MGO moiety close to the aromatic ring. (53−55) However, Hidalgo and co-workers (56) observed that the carbonyl group was conjugated with the aromatic ring after heating GO and resorcinol together at 100 °C for 3 h, which implies that isomerization may also occur under physiological conditions to extend the conjugation. The unsubstituted carbon 2 and 6 should be the major active site for scavenging DCs. Specifically, the trapping reactions between phenols and DCs are hydroxyalkylation and aromatic substitution reactions, and the hydroxyl groups in the aromatic ring could increase the reactivity of unsubstituted carbon atoms to attack carbonyl carbon atoms. Conversely, the replacement of hydroxyl in C3 by methoxyl leads to the loss of MGO trapping capacity of FA and [6]-shogaol, (11) which means that the replaced methoxyl group decreases the activity of C2 and C6 because both hydroxyl and methoxyl are ortho–para directing groups.

Figure 6

Figure 6. Proposed mechanism of reaction for trapping of MGO by CA under simulated physiological conditions.

High Resolution Image
Download MS PowerPoint Slide
Concerning HMW-CM as sources of hydroxycinnamic acids, especially CGAs and CA, the presence of melanoidin-bound phenolic structures may also enhance DC trapping efficacy of each other as a result of additive effects. The ability of melanoidin-bound phenolics in scavenging DCs follows recently pointed out effects of the food matrix in modulating chemical reactivity: (57) structural organization at the molecular and macroscopic level is responsible of the reaction routes in a specific food environment.
In summary, the present study revealed that polyphenol-rich melanoidins, such as HMW-CM and HMW-COM, can scavenge DCs, thus mitigating the negative consequences of their reaction with other macromolecules in physiological conditions. This is the first report that presents the tentative detection of mono- and di-MGO adducts of CA, which indicates that CA scavenges DCs through trapping reactions. Partial hydrolysis and the release of melanoidin-bound phenolic compounds illustrate that phenolic compounds bound to macromolecules are still active to scavenge DCs in vitro and confirm the possibility of using antioxidant dietary fibers as functional ingredients to quench dicarbonyl species along the gastrointestinal tract.

Supporting Information

ARTICLE SECTIONS
Jump To

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.jafc.9b03744.

  • Chromatograms of the (A) standard mixture, (B) saline-treated HMW-CM, (C) acid-hydrolyzed HMW-CM, and (D) alkali-hydrolyzed HMW-CM; dose-dependent results for GO, MGO, and DA trapping capacities (168 h) of CA, 3-CQA, and FA (0.128-0.853 mmol/L); and main fragmentation patterns of CA (A), mono-MGO-CA (B), and di-MGO-CA (C) in the negative-ion mode (PDF)

Terms & Conditions

Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

Author Information

ARTICLE SECTIONS
Jump To
  • Corresponding Author
  • Authors
    • Hao Zhang - School of Food Science and Technology, Jiangnan University, Wuxi 214122, China;  Food Quality & Design Group, Wageningen University & Research, Wageningen NL-6708 WG, Netherlands
    • Hui Zhang - School of Food Science and Technology, Jiangnan University, Wuxi 214122, China;  Orcidhttp://orcid.org/0000-0002-0756-9334
    • Antonio Dario Troise - Department of Agricultural Sciences, University of Naples ‘‘Federico II’’, 80055 Portici, Italy
  • Notes
    The authors declare no competing financial interest.

Acknowledgments

ARTICLE SECTIONS
Jump To

We gratefully acknowledge the financial support from the China Scholarship Council.

Abbreviations

ARTICLE SECTIONS
Jump To
3-CQA

3-caffeoylquinic acid

2-MQX

2-methylquinoxaline

2,3-MQX

2,3-dimethylquinoxaline

CA

caffeic acid

CGAs

chlorogenic acids

DA

diacetyl

DCs

dicarbonyl compounds

DETAPAC

diethylenetriaminepentaacetic acid

EDTA

ethylenediaminetetraacetic acid

EIC

extracted ion chromatogram

FA

ferulic acid

GO

glyoxal

HMW-CM

high-molecular weight coffee melanoidins

HMW-COM

high-molecular weight cocoa melanoidins

HMW-BM

high-molecular weight bread melanoidins

MGO

methylglyoxal

OPD

o-phenylenediamine

PM

pyridoxamine

QX

quinoxaline

LC–MS/MS

liquid chromatography–tandem mass spectrometry

SIM

selected ion monitoring

SRM

selected reaction monitoring

TIC

total ion chromatogram

References

ARTICLE SECTIONS
Jump To

This article references 57 other publications.

  1. 1
    Smuda, M.; Glomb, M. A. Fragmentation Pathways during Maillard-Induced Carbohydrate Degradation. J. Agric. Food Chem. 2013, 61, 10198– 10208,  DOI: 10.1021/jf305117s
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    1
    Fragmentation pathways during Maillard-induced carbohydrate degradation
    Smuda, Mareen; Glomb, Marcus A.
    Journal of Agricultural and Food Chemistry (2013), 61 (43), 10198-10208CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    A review. The Maillard reaction network with focus on the chem. of dicarbonyl structures causes considerable interest of research groups in food chem. and medical science, resp. Dicarbonyl compds. are well established as the central intermediates in the nonenzymic browning reaction and have been verified to be responsible for advanced glycation endproduct (AGE) formation. A multitude of Maillard dicarbonyls covering the range of the intact carbon backbone down to C3 and C2 fragments were detected in several carbohydrate systems, for example, in glucose, maltose, or ascorbic acid reactions. By definition, dicarbonyls with a C2-C5 carbon backbone must originate by fission of the original carbon skeleton. The present review deals with the five major mechanisms reported in the literature for dicarbonyl decompn.: (i) retro-aldol fragmentation, (ii) hydrolytic α-dicarbonyl cleavage, (iii) oxidative α-dicarbonyl cleavage, (iv) hydrolytic β-dicarbonyl cleavage, and (v) amine-induced β-dicarbonyl cleavage.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXivVWgsrc%253D&md5=35e66a63d971683e9b73747f2dac5019
  2. 2
    Thornalley, P. J.; Langborg, A.; Minhas, H. S. Formation of Glyoxal, Methylglyoxal and 8-Deoxyglucosone in the Glycation of Proteins by Glucose. Biochem. J. 1999, 344, 109– 116,  DOI: 10.1042/bj3440109
    [Crossref], [PubMed], [CAS], Google Scholar
    2
    Formation of glyoxal, methylglyoxal and 3-deoxyglucosone in the glycation of proteins by glucose
    Thornalley, Paul J.; Langborg, Annika; Minhas, Harjit S.
    Biochemical Journal (1999), 344 (1), 109-116CODEN: BIJOAK; ISSN:0264-6021. (Portland Press Ltd.)
    The glycation of proteins by glucose has been linked to the development of diabetic complications and other diseases. Early glycation is thought to involve the reaction of glucose with N-terminal and lysyl side chain amino groups to form Schiff's base and fructosamine adducts. The formation of the α-oxoaldehydes, glyoxal, methylglyoxal and 3-deoxyglucosone, in early glycation was investigated. Glucose (50 mM) degraded slowly at pH 7.4 and 37°C to form glyoxal, methylglyoxal and 3-deoxyglucosone throughout a 3-wk incubation period. Addn. of t-BOC-lysine and human serum albumin increased the rate of formation of α-oxoaldehydes - except glyoxal and methylglyoxal concns. were low with albumin, as expected from the high reactivity of glyoxal and methylglyoxal with arginine residues. The degrdn. of fructosyl-lysine also formed glyoxal, methylglyoxal and 3-deoxyglucosone. α-Oxoaldehyde formation was dependent on the concn. of phosphate buffer and availability of trace metal ions. This suggests that α-oxoaldehydes were formed in early glycation from the degrdn. of glucose and Schiff's base adduct. Since α-oxoaldehydes are important precursors of advanced glycation adducts, these adducts may be formed from early and advanced glycation processes. Short periods of hyperglycemia, as occur in impaired glucose tolerance, may be sufficient to increase the concns. of α-oxoaldehydes in vivo.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1MXns1yjtrY%253D&md5=ba9ad4d19d895cb31724d48dfeaeac8a
  3. 3
    Hollnagel, A.; Kroh, L. W. Formation of α-Dicarbonyl Fragments from Mono- and Disaccharides under Caramelization and Maillard Reaction Conditions. Z. Lebensmittelunters. Forsch. A 1998, 207, 50– 54,  DOI: 10.1007/s002170050294
    [Crossref], [CAS], Google Scholar
    3
    Formation of α-dicarbonyl fragments from mono- and disaccharides under caramelization and Maillard reaction conditions
    Hollnagel, A.; Kroh, L. W.
    Zeitschrift fuer Lebensmittel-Untersuchung und -Forschung A: Food Research and Technology (1998), 207 (1), 50-54CODEN: ZLFAFA; ISSN:1431-4630. (Springer-Verlag)
    Glyoxal, methylglyoxal, and diacetyl were identified as reaction products from non-enzymic browning of D-glucose (Glc), D-fructose (Fru), maltose, and maltulose. The α-dicarbonyl compds. were quantified throughout the reaction. Monosaccharides formed more dicarbonyl fragments than disaccharides and Glc formed more than Fru. It is suggested that Fru tends to yield cyclic products rather than fragmentation products under the reaction conditions used. Furthermore, a mechanism for the fragmentation of disaccharides is proposed.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1cXkslCgsrw%253D&md5=d28458b612c96689233938dcd00fb5ce
  4. 4
    Delgado-Andrade, C.; Fogliano, V. Dietary Advanced Glycosylation End-Products (DAGEs) and Melanoidins Formed through the Maillard Reaction: Physiological Consequences of Their Intake. Annu. Rev. Food Sci. Technol. 2018, 9, 271– 291,  DOI: 10.1146/annurev-food-030117-012441
    [Crossref], [PubMed], [CAS], Google Scholar
    4
    Dietary Advanced Glycosylation End-Products (dAGEs) and Melanoidins Formed through the Maillard Reaction: Physiological Consequences of their Intake
    Delgado-Andrade, Cristina; Fogliano, Vincenzo
    Annual Review of Food Science and Technology (2018), 9 (), 271-291CODEN: ARFSBV; ISSN:1941-1413. (Annual Reviews)
    The main purpose of this review is to clarify whether the consumption of food rich in melanoidins and dietary advanced glycosylation end-products (dAGEs) is harmful or beneficial for human health. There are conflicting results on their harmful effects in the literature, partly due to a methodol. issue in how dAGEs are detd. in food. Melanoidins have pos. functions particularly within the gastrointestinal tract, whereas the intake of dAGEs has controversial physiol. consequences. Most of the in vivo intervention trials were done comparing boiled vs. roasted diet (low and high dAGE, resp.). However, these studies can be biased by different lipid oxidn. and by different calorie d. of foods in the two conditions. The attraction that humans have to cooked foods is linked to the benefits they have had during mankind's evolution. The goal for food technologists is to design low-energy-dense products that can satisfy humans' attraction to rewarding cooked foods.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhtlOguro%253D&md5=bdd63b459d68bc22272ea8a035fc0142
  5. 5
    Rabbani, N.; Thornalley, P. J. Methylglyoxal, Glyoxalase 1 and the Dicarbonyl Proteome. Amino Acids 2012, 42, 1133– 1142,  DOI: 10.1007/s00726-010-0783-0
    [Crossref], [PubMed], [CAS], Google Scholar
    5
    Methylglyoxal, glyoxalase 1 and the dicarbonyl proteome
    Rabbani, Naila; Thornalley, Paul J.
    Amino Acids (2012), 42 (4), 1133-1142CODEN: AACIE6; ISSN:0939-4451. (SpringerWienNewYork)
    A review. Methylglyoxal (MG) is a potent protein glycating agent. Glycation is directed to guanidino groups of arginine residues forming mainly hydroimidazolone Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) residues. MG-H1 formation is damaging to the proteome as modification is often directed to functionally important Arg residues. MG-H1 content of proteins is quantified by stable isotopic diln. anal. tandem mass spectrometry and also by immunoblotting with specific monoclonal antibodies. MG-glycated proteins undergo cellular proteolysis and release MG-H1 free adduct for excretion. MG-H1 residues were found in proteins of animals, plants, bacteria, fungi and protoctista. MG-H1 is often the major advanced glycation endproduct in proteins of tissues and body fluids, increasing in diabetes and assocd. vascular complications, renal failure, cirrhosis, Alzheimer's disease, arthritis, Parkinson's disease and aging. Glyoxalase 1 and aldo-keto reductase 1B1 metabolize >99% MG to innocuous products and thereby protect the proteome, providing an enzymic defense against MG-mediated glycation. Proteins susceptible to MG modification with related functional impairment are called the "dicarbonyl proteome" (DCP). DCP includes albumin, Hb, transcription factors, mitochondrial proteins, extracellular matrix proteins, lens crystallins and other proteins. DCP component proteins are linked to mitochondrial dysfunction in diabetes and aging, oxidative stress, dyslipidemia, cell detachment and anoikis and apoptosis. Biochem. and physiol. susceptibility of a protein to modification by MG and sensitivity of biochem. pathways and physiol. systems to related functional impairment under challenge of physiol. relevant increases in MG exposure are key concepts. Improved understanding of the DCP will likely have profound importance for human health, longevity and treatment of disease.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XjsVWhsrc%253D&md5=717865fe0bf51f81c51df0c21e130541
  6. 6
    Ahmad, S.; Moinuddin, M.; Shahab, U.; Habib, S.; Salman Khan, M.; Alam, K.; Ali, A. Glycoxidative Damage to Human DNA: Neo-Antigenic Epitopes on DNA Molecule Could Be a Possible Reason for Autoimmune Response in Type 1 Diabetes. Glycobiology 2014, 24, 281– 291,  DOI: 10.1093/glycob/cwt109
    [Crossref], [PubMed], [CAS], Google Scholar
    6
    Glycoxidative damage to human DNA: Neo-antigenic epitopes on DNA molecule could be a possible reason for autoimmune response in type 1 diabetes
    Ahmad, Saheem; Moinuddin; Shahab, Uzma; Habib, Safia; Salman Khan, M.; Alam, Khursheed; Ali, Asif
    Glycobiology (2014), 24 (3), 281-291CODEN: GLYCE3; ISSN:0959-6658. (Oxford University Press)
    Advanced glycation end-products (AGEs) are known to be mutagenic, diabetogenic and vascular disease risk factors. Methylglyoxal (MG) is a dicarbonyl species that reacts with biol. macromol. (proteins, DNA and lipids) to give AGEs. Nonenzymic glycation of MG with lysine (Lys) in the presence of copper (Cu2+) is reported to generate reactive oxygen species (ROS) capable of causing DNA damage. We show that DNA modification in MG-Lys-Cu2+ system results in the generation of strand breaks, base modification, hyperchromicity and increased fluorescence intensity. Superoxide generation in the MG-Lys system was found to be significantly higher when compared with that in the MG and Lys alone. Moreover, D-penicillamine and pyridoxal phosphate significantly inhibited the formation of glycation products. The presence of a major DNA glycation adduct, N2-carboxyethyl-2'-deoxyguanosine (CEdG), was detected by high performance liq. chromatog. (HPLC) and confirmed by NMR (NMR). As reported earlier, modified DNA (MG-Lys-Cu2+-DNA) was highly immunogenic in exptl. animals. Furthermore, induced anti-MG-Lys-Cu2+-DNA antibodies were effective probe for detecting glycoxidative lesions in human genomic DNA of type I diabetes patients. Our results clearly imply that interaction of MG-Lys and Cu2+ leads to the formation of AGEs and also the prodn. of potent ROS, capable of causing DNA damage, thereby playing an important role in diabetes mellitus.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFWku7w%253D&md5=50fd79691a7ee0d7fd82ed560767f52e
  7. 7
    Sato, T.; Iwaki, M.; Shimogaito, N.; Wu, X.; Yamagishi, S.-i.; Takeuchi, M. TAGE (Toxic AGEs) Theory in Diabetic Complications. Curr. Mol. Med. 2006, 6, 351– 358,  DOI: 10.2174/156652406776894536
    [Crossref], [PubMed], [CAS], Google Scholar
    7
    TAGE (toxic AGEs) theory in diabetic complications
    Sato, Takashi; Iwaki, Mina; Shimogaito, Noriko; Wu, Xuegang; Yamagishi, Sho-ichi; Takeuchi, Masayoshi
    Current Molecular Medicine (2006), 6 (3), 351-358CODEN: CMMUBP; ISSN:1566-5240. (Bentham Science Publishers Ltd.)
    A review. Diabetic complication is a leading cause of acquired blindness, end-stage renal failure, a variety of neuropathies and accelerated atherosclerosis. Chronic hyperglycemia is initially involved in the pathogenesis of diabetic micro- and macro-vascular complications via various metabolic derangements. High glucose increased prodn. of various types of advanced glycation end-products (AGEs). Recently, we found that glyceraldehyde-derived AGEs (AGE-2) play an important role in the pathogenesis of angiopathy in diabetic patients. There is considerable interest in receptor for AGEs (RAGE) found on many cell types, particularly those affected in diabetes. Recent studies suggest that interaction of AGE-2 (predominantly structure of toxic AGEs; TAGE) with RAGE alters intracellular signaling, gene expression, release of pro-inflammatory mols. and prodn. of reactive oxygen species (ROS) that contribute towards the pathol. of diabetic complications. We propose three pathways for the in vivo formation of AGE-2 precursor, glyceraldehyde, such as i) glycolytic pathway, ii) polyol pathway, and iii) fructose metabolic pathway. Glyceraldehyde can be transported or can leak passively across the plasma membrane. It can react non-enzymically with proteins to lead to accelerated formation of TAGE at both intracellularly and extracellularly. In this review, we discuss the mol. mechanisms of diabetic complications, esp. focusing on toxic AGEs (TAGE) and their receptor (RAGE) system.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XlsVGmtr4%253D&md5=40c9d078d42073205fab0927d140e140
  8. 8
    Gaens, K. H.; Stehouwer, C. D.; Schalkwijk, C. G. Advanced Glycation Endproducts and Its Receptor for Advanced Glycation Endproducts in Obesity. Curr. Opin. Lipidol. 2013, 24, 4– 11,  DOI: 10.1097/mol.0b013e32835aea13
    [Crossref], [PubMed], [CAS], Google Scholar
    8
    Advanced glycation endproducts and its receptor for advanced glycation endproducts in obesity
    Gaens, Katrien Hj.; Stehouwer, Coen Da.; Schalkwijk, Casper G.
    Current Opinion in Lipidology (2013), 24 (1), 4-11CODEN: COPLEU; ISSN:0957-9672. (Lippincott Williams & Wilkins)
    Purpose of review: To highlight the potential importance of advanced glycation endproducts (AGEs) and advanced-lipoxidn. endproducts (ALEs) in obesity and obesity-related complications, and the contribution of the receptor for advanced glycation endproducts (RAGE) and the glyoxylase defense system therein. Recent findings: Formation of AGEs/ALEs and its precursors, including methylglyoxal (MGO), are increased in conditions characterized by hyperglycemia, hyperlipidemia and enhanced oxidative stress. This metabolic profile is generally considered typical for obesity. Increased plasma and/or tissue levels of MGO and of specific AGEs/ALEs, such as N-(carboxymethyl)lysine (CML), in obesity have recently been described. In addn. to increased formation, the suppressed defense system in obesity against AGEs/ALEs formation, i.e., the glyoxylase system, will further contribute to AGEs/ALEs formation in obesity. AGEs/ALEs are not inert. In-vitro studies showed that AGEs induced the prodn. of inflammatory mediators in adipocytes and macrophages via RAGE activation, which may subsequently contribute to the development of obesity-related complications. Summary: The recognition of an enhanced AGEs/ALEs formation in adipose tissue and the biol. consequences thereof may lead to a further understanding of underlying mechanisms in dysregulated prodn. of adipokines in obesity.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXktlWmsA%253D%253D&md5=692b48aa746f329931abc8b24815f412
  9. 9
    Wellsknecht, K. J.; Zyzak, D. V.; Litchfield, J. E.; Thorpe, S. R.; Baynes, J. W. Identification of Glyoxal As the Dicarbonyl Sugar Formed on Autoxidation of Glucose - Relevance To Pathways of the Maillard Reaction in-Vivo. Diabetes 1994, 43, A96
    Google Scholar
    There is no corresponding record for this reference.
  10. 10
    Glomb, M. A.; Monnier, V. M. Mechanism of Protein Modification by Glyoxal and Glycolaldehyde, Reactive Intermediates of the Maillard Reaction. J. Biol. Chem. 1995, 270, 10017– 10026,  DOI: 10.1074/jbc.270.17.10017
    [Crossref], [PubMed], [CAS], Google Scholar
    10
    Mechanism of protein modification by glyoxal and glycolaldehyde, reactive intermediates of the Maillard reaction
    Glomb, Marcus A.; Monnier, Vincent M.
    Journal of Biological Chemistry (1995), 270 (17), 10017-26CODEN: JBCHA3; ISSN:0021-9258. (American Society for Biochemistry and Molecular Biology)
    The role of glyoxal and glycolaldehyde in protein crosslinking and Nε-(carboxymethyl)lysine (CML) formation during Maillard reaction under physiol. conditions was investigated. Incubation of bovine serum albumin with these reagents lead to rapid formation of C-2-imine cross-links and CML. Initial CML formation rate from glyoxal was not dependent on oxidn., suggesting an intramol. Cannizzaro reaction. CML formation from glucose/lysine or Amadori product of both was strongly dependent on oxidn. Blocking of Amadori product by boric acid totally suppressed CML formation from Amadori product, but only by 37% in the glucose/lysine system. Trapping of glyoxal with aminoguanidine hardly suppressed CML formation from Amadori product, whereas it blocked 50% of CML prodn. in the glucose/lysine system. While these results would support a significant role for glucose autoxidn. in CML formation, the addn. of lysine to a glucose/aminoguanidine incubation system catalyzed glyoxal-triazine formation 7-fold, thereby strongly suggesting that glucose autoxidn. is not a factor for glyoxal-mediated CML formation. Based on these results, it can be estd. that approx. 50% of the CML forming in a glucose/lysine system originates from oxidn. of Amadori product, and 40-50% originates from a pre-Amadori stage largely independent from glucose autoxidn.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2MXltlWnsrY%253D&md5=87bb958f71d4878ef88e3f476d851442
  11. 11
    Huang, Q.; Wang, P.; Zhu, Y.; Lv, L.; Sang, S. Additive Capacity of 6 -Shogaol and Epicatechin To Trap Methylglyoxal. J. Agric. Food Chem. 2017, 65, 8356– 8362,  DOI: 10.1021/acs.jafc.7b02917
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    11
    Additive Capacity of [6]-Shogaol and Epicatechin To Trap Methylglyoxal
    Huang, Qiju; Wang, Pei; Zhu, Yingdong; Lv, Lishuang; Sang, Shengmin
    Journal of Agricultural and Food Chemistry (2017), 65 (38), 8356-8362CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    Methylglyoxal (MGO), a reactive dicarbonyl species, is thought to contribute to the development of long-term pathol. diabetes as a direct toxin or as an active precursor of advanced glycation end products (AGEs). Trapping MGO by dietary phenols to inhibit the MGO induced AGE formation is an approach for alleviating diabetic complications. The present study investigated whether dietary compds. with different structures and active sites have the additive capacity to trap MGO. Ginger phenolic constituent [6]-shogaol and tea flavonoid (-)-epicatechin were selected and tested under simulated physiol. conditions, showing that they additively trapped about 41% MGO at a concn. of 10 μM within 24 h. Furthermore, whether [6]-shogaol and epicatechin can retain their MGO trapping efficacy in vivo or a biotransformation limits their MGO trapping capacity remain virtually unknown. An acute mouse study was carried out by giving a single dose of [6]-shogaol, epicatechin, and the combination of both ([6]-shogaol + epicatechin) through oral gavage. A mono-MGO adduct of [6]-shogaol was identified from [6]-shogaol and [6]-shogaol + epicatechin treated mice, and mono- and di-MGO adducts of epicatechin and its metabolite, 3'-O-Me epicatechin, were detected in urine samples collected from epicatechin and [6]-shogaol + epicatechin treated mice. To the knowledge, this is the first study demonstrating the additive MGO trapping efficacy of [6]-shogaol and epicatechin and that [6]-shogaol and epicatechin retained their MGO trapping capacity in mice.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsVagu7jP&md5=85ec2ece4042f3f316dbef152db930b1
  12. 12
    Troise, A. D.; Fiore, A.; Colantuono, A.; Kokkinidou, S.; Peterson, D. G.; Fogliano, V. Effect of Olive Mill Wastewater Phenol Compounds on Reactive Carbonyl Species and Maillard Reaction End-Products in Ultrahigh-Temperature-Treated Milk. J. Agric. Food Chem. 2014, 62, 10092– 10100,  DOI: 10.1021/jf503329d
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    12
    Effect of Olive Mill Wastewater Phenol Compounds on Reactive Carbonyl Species and Maillard Reaction End-Products in Ultrahigh-Temperature-Treated Milk
    Troise, Antonio Dario; Fiore, Alberto; Colantuono, Antonio; Kokkinidou, Smaro; Peterson, Devin G.; Fogliano, Vincenzo
    Journal of Agricultural and Food Chemistry (2014), 62 (41), 10092-10100CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    Thermal processing and Maillard reaction (MR) affect the nutritional and sensorial qualities of milk. In this paper an olive mill wastewater phenolic powder (OMW) was tested as a functional ingredient for inhibiting MR development in ultrahigh-temp. (UHT)-treated milk. OMW was added to milk at 0.1 and 0.05% w/v before UHT treatment, and the concn. of MR products was monitored to verify the effect of OMW phenols in controlling the MR. Results revealed that OMW is able to trap the reactive carbonyl species such as hydroxycarbonyls and dicarbonyls, which in turn led to the increase of Maillard-derived off-flavor development. The effect of OMW on the formation of Amadori products and N-ε-(carboxymethyl)-lysine (CML) showed that oxidative cleavage, C2-C6 cyclization, and the consequent reactive carbonyl species formation were also inhibited by OMW. Data indicated that OMW is a functional ingredient able to control the MR and to improve the nutritional and sensorial attributes of milk.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsFygtb7M&md5=3b522fb86b94e04f67c5e2311883b603
  13. 13
    Gugliucci, A.; Bastos, D. H. M.; Schulze, J.; Souza, M. F. F. Caffeic and Chlorogenic Acids in Ilex Paraguariensis Extracts Are the Main Inhibitors of AGE Generation by Methylglyoxal in Model Proteins. Fitoterapia 2009, 80, 339– 344,  DOI: 10.1016/j.fitote.2009.04.007
    [Crossref], [PubMed], [CAS], Google Scholar
    13
    Caffeic and chlorogenic acids in Ilex paraguariensis extracts are the main inhibitors of AGE generation by methylglyoxal in model proteins
    Gugliucci, A.; Bastos, Deborah H. Markowicz; Schulze, John; Souza, Marina F. Ferreira
    Fitoterapia (2009), 80 (6), 339-344CODEN: FTRPAE; ISSN:0367-326X. (Elsevier B.V.)
    The present study concs. on the evaluation of the anti-glycation effect of some bioactive substances present in yerba mate (Ilex paraguariensis): 5-caffeoylquinic acid, caffeic acid and a sapogenin (oleanolic acid). Bovine serum albumin and histones were incubated in the presence of methylglyoxal with or without the addn. of 5-caffeoylquinic acid, caffeic acid and oleanolic acid. After the incubation period, advanced glycation end product (AGE) fluorescence spectra were performed and protein structural changes were evaluated by Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis. Chlorogenic acid, caffeic acid are the main substances responsible for the anti-glycation effect of mate tea.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXoslWksro%253D&md5=2a40f5d42b904e3cf824b590d8b13c03
  14. 14
    Treibmann, S.; Spengler, F.; Degen, J.; Löbner, J.; Henle, T. Studies on the Formation of 3-Deoxyglucosone- and Methylglyoxal-Derived Hydroimidazolones of Creatine during Heat Treatment of Meat. J. Agric. Food Chem. 2019, 67, 5874– 5881,  DOI: 10.1021/acs.jafc.9b01243
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    14
    Studies on the Formation of 3-Deoxyglucosone- and Methylglyoxal-Derived Hydroimidazolones of Creatine during Heat Treatment of Meat
    Treibmann, Stephanie; Spengler, Franz; Degen, Julia; Loebner, Juergen; Henle, Thomas
    Journal of Agricultural and Food Chemistry (2019), 67 (20), 5874-5881CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    Dicarbonyl compds. such as methylglyoxal (MGO) and 3-deoxyglucosone (3-DG) are formed via caramelization and the Maillard reaction in food during heating or in vivo as byproducts of glycolysis. Recently, it was shown that creatine, an amino compd. linked to the energy metab. in vertebrate muscle, reacts rapidly with methylglyoxal under physiol. conditions to form N-(4-methyl-5-oxo-1-imidazolin-2-yl)sarcosine (MG-HCr), a methylglyoxal-derived hydroimidazolone of creatine. Based on the observation that heated meat contains only small amts. of MGO and 3-DG when compared to many other foodstuffs, the aim of this study was to investigate a possible reaction of creatine with 3-DG and MGO in meat. From incubation mixts. consisting of 3-DG and creatine, a new hydroimidazolone of creatine, namely N-(4-butyl-1,2,3-triol-5-oxo-1-imidazolin-2-yl)sarcosine (3-DG-HCr), was isolated and characterized via spectroscopic means. To quantitate 3-DG-HCr and MG-HCr, meat and fish products were analyzed via HPLC-MS/MS using isotopically labeled std. material. Whereas samples of raw fish and meat contained only trace amts. of the hydroimidazolones (below 5 μg/kg), up to 28.3 mg/kg MG-HCr and up to 15.3 mg/kg 3-DG-HCr were found in meat and fish products. The concns. were dependent on the heat treatment and presumably on the smoking process. In comparison to the lysine and arginine derivs. CEL, pyrraline, and MG-H1, the derivatization rate of creatine as MG-HCr and 3-DG-HCr was higher than of lysine and arginine, which clearly demonstrates the 1,2-dicarbonyl scavenging properties of creatine in meat.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXoslSlsrc%253D&md5=d3eacbc65f86542c4458a333000b1327
  15. 15
    Löbner, J.; Degen, J.; Henle, T. Creatine Is a Scavenger for Methylglyoxal under Physiological Conditions via Formation of N -(4-Methyl-5-Oxo-1-Imidazolin-2-Yl)Sarcosine (MG-HCr). J. Agric. Food Chem. 2015, 63, 2249– 2256,  DOI: 10.1021/jf505998z
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    15
    Creatine is a scavenger for methylglyoxal under physiological conditions via formation of N-(4-methyl-5-oxo-1-imidazolin-2-yl)sarcosine (MG-HCr)
    Lobner Jurgen; Degen Julia; Henle Thomas
    Journal of agricultural and food chemistry (2015), 63 (8), 2249-56 ISSN:.
    Following incubation of methylglyoxal and creatine under physiological conditions, N-(4-methyl-5-oxo-1-imidazolin-2-yl)sarcosine (MG-HCr) was isolated and identified by NMR and mass spectrometry. Due to its rapid formation, MG-HCr represents a specific product following "scavenging" of methylglyoxal by creatine. Using hydrophilic interaction chromatography coupled to mass spectrometry, MG-HCr was analyzed in urine samples of healthy volunteers. Daily MG-HCr excretion of nonvegetarians ranged from 0.35 to 3.84 μmol/24 h urine (median: 0.90 μmol/24 h urine) and of vegetarians from 0.11 to 0.31 μmol/24 h urine (median: 0.19 μmol/24 h urine), indicating that formation of MG-HCr in vivo is influenced by the dietary intake of creatine. The trapping of methylglyoxal by creatine may delay the formation of advanced glycation compounds in vivo and, therefore, could be of special importance in situations in which the body has to deal with pathophysiologically increased amounts of dicarbonyl compounds ("carbonyl stress"), for instance in diabetic patients.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC2MrjtVCrtg%253D%253D&md5=05e9b53c0367acac620c6ee705c54dc8
  16. 16
    Rabbani, N.; Xue, M.; Thornalley, P. J. Dicarbonyls and Glyoxalase in Disease Mechanisms and Clinical Therapeutics. Glycoconjugate J. 2016, 33, 513– 525,  DOI: 10.1007/s10719-016-9705-z
    [Crossref], [PubMed], [CAS], Google Scholar
    16
    Dicarbonyls and glyoxalase in disease mechanisms and clinical therapeutics
    Rabbani, Naila; Xue, Mingzhan; Thornalley, Paul J.
    Glycoconjugate Journal (2016), 33 (4), 513-525CODEN: GLJOEW; ISSN:0282-0080. (Springer)
    The reactive dicarbonyl metabolite methylglyoxal (MG) is the precursor of the major quant. advanced glycation endproducts (AGEs) in physiol. systems - arginine-derived hydroimidazolones and deoxyguanosine-derived imidazopurinones. The glyoxalase system in the cytoplasm of cells provides the primary defense against dicarbonyl glycation by catalyzing the metab. of MG and related reactive dicarbonyls. Dicarbonyl stress is the abnormal accumulation of dicarbonyl metabolites leading to increased protein and DNA modification contributing to cell and tissue dysfunction in ageing and disease. It is produced endogenously by increased formation and/or decreased metab. of dicarbonyl metabolites. Dicarbonyl stress contributes to ageing, disease and activity of cytotoxic chemotherapeutic agents. It contributes to ageing through age-related decline in glyoxalase 1 (Glo-1) activity. Glo-1 has a dual role in cancer as a tumor suppressor protein prior to tumor development and mediator of multi-drug resistance in cancer treatment, implicating dicarbonyl glycation of DNA in carcinogenesis and dicarbonyl-driven cytotoxicity in mechanism of action of anticancer drugs. Glo-1 is a driver of cardiovascular disease, likely through dicarbonyl stress-driven dyslipidemia and vascular cell dysfunction. Dicarbonyl stress is also a contributing mediator of obesity and vascular complications of diabetes. There are also emerging roles in neurol. disorders. Glo-1 responds to dicarbonyl stress to enhance cytoprotection at the transcriptional level through stress-responsive increase of Glo-1 expression. Small mol. Glo-1 inducers are in clin. development for improved metabolic, vascular and renal health and Glo-1 inhibitors in preclin. development for multidrug resistant cancer chemotherapy.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhtFGlsbjF&md5=b397a992b016d4b78d39f6081437d196
  17. 17
    Baynes, J. W.; Thorpe, S. R. Glycoxidation and Lipoxidation in Atherogenesis. Free Radical Biol. Med. 2000, 28, 1708– 1716,  DOI: 10.1016/s0891-5849(00)00228-8
    [Crossref], [PubMed], [CAS], Google Scholar
    17
    Glycoxidation and lipoxidation in atherogenesis
    Baynes, J. W.; Thorpe, S. R.
    Free Radical Biology & Medicine (2000), 28 (12), 1708-1716CODEN: FRBMEH; ISSN:0891-5849. (Elsevier Science Inc.)
    A review with 73 refs. Atherosclerosis may be viewed as an age-related disease initiated by nonenzymic, chem. reactions in a biol. system. The peroxidn. of lipids in lipoproteins in the vascular wall leads to local prodn. of reactive carbonyl species that mediate recruitment of macrophages, cellular activation and proliferation, and chem. modification of vascular proteins by advanced lipoxidn. end-products (ALEs). The ALEs and their precursors affect the structure and function of the vascular wall, setting the stage for atherogenesis. The increased risk for atherosclerosis in diabetes may result from addnl. carbonyl prodn. from carbohydrates and addnl. chem. modification of proteins by advanced glycation end-products (AGEs). Failure to maintain homeostasis and the increase in oxidizable substrate (lipid) alone, rather than oxidative stress, is the likely source of the increase in reactive carbonyl precursors and the resultant ALEs and AGEs in atherosclerosis. Nucleophilic AGE-inhibitors, such as aminoguanidine and pyridoxamine, which trap reactive carbonyls and inhibit the formation of AGEs in diabetes, also trap bioactive lipids and precursors of ALEs in atherosclerosis. These drugs should be effective in retarding the development of atherosclerosis, even in nondiabetic patients.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3cXls1Giu7k%253D&md5=8ab4fef4917dd773e9c794f2f97a0ef8
  18. 18
    Davies, M. J. Protein Oxidation and Peroxidation. Biochem. J. 2016, 473, 805– 825,  DOI: 10.1042/bj20151227
    [Crossref], [PubMed], [CAS], Google Scholar
    18
    Protein oxidation and peroxidation
    Davies, Michael J.
    Biochemical Journal (2016), 473 (7), 805-825CODEN: BIJOAK; ISSN:0264-6021. (Portland Press Ltd.)
    Proteins are major targets for radicals and two-electron oxidants in biol. systems due to their abundance and high rate consts. for reaction. With highly reactive radicals damage occurs at multiple side-chain and backbone sites. Less reactive species show greater selectivity with regard to the residues targeted and their spatial location. Modification can result in increased side-chain hydrophilicity, side-chain and backbone fragmentation, aggregation via covalent crosslinking or hydrophobic interactions, protein unfolding and altered conformation, altered interactions with biol. partners and modified turnover. In the presence of O2, high yields of peroxyl radicals and peroxides (protein peroxidn.) are formed; the latter account for up to 70% of the initial oxidant flux. Protein peroxides can oxidize both proteins and other targets. One-electron redn. results in addnl. radicals and chain reactions with alcs. and carbonyls as major products; the latter are commonly used markers of protein damage. Direct oxidn. of cysteine (and less commonly) methionine residues is a major reaction; this is typically faster than with H2O2, and results in altered protein activity and function. Unlike H2O2, which is rapidly removed by protective enzymes, protein peroxides are only slowly removed, and catabolism is a major fate. Although turnover of modified proteins by proteasomal and lysosomal enzymes, and other proteases (e.g. mitochondrial Lon), can be efficient, protein hydroperoxides inhibit these pathways and this may contribute to the accumulation of modified proteins in cells. Available evidence supports an assocn. between protein oxidn. and multiple human pathologies, but whether this link is causal remains to be established.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XkvFClsLg%253D&md5=fd1192a5ac27edeb8583228d439afca9
  19. 19
    Van den Eynde, M. D. G.; Geleijnse, J. M.; Scheijen, J. L. J. M.; Hanssen, N. M. J.; Dower, J. I.; Afman, L. A.; Stehouwer, C. D. A.; Hollman, P. C. H.; Schalkwijk, C. G. Quercetin, but Not Epicatechin, Decreases Plasma Concentrations of Methylglyoxal in Adults in a Randomized, Double-Blind, Placebo-Controlled, Crossover Trial with Pure Flavonoids. J. Nutr. 2018, 148, 1911– 1916,  DOI: 10.1093/jn/nxy236
    [Crossref], [PubMed], [CAS], Google Scholar
    19
    Quercetin, but Not Epicatechin, Decreases Plasma Concentrations of Methylglyoxal in Adults in a Randomized, Double-Blind, Placebo-Controlled, Crossover Trial with Pure Flavonoids
    Van den Eynde Mathias D G; Scheijen Jean L J M; Hanssen Nordin M J; Stehouwer Coen D A; Schalkwijk Casper G; Van den Eynde Mathias D G; Scheijen Jean L J M; Hanssen Nordin M J; Stehouwer Coen D A; Schalkwijk Casper G; Geleijnse Johanna M; Dower James I; Afman Lydia A; Hollman Peter C H
    The Journal of nutrition (2018), 148 (12), 1911-1916 ISSN:.
    Background: Methylglyoxal (MGO) is the most potent precursor of advanced glycation end products (AGEs). MGO and AGEs have been associated with diabetes, its complications, and other age-related diseases. Experimental studies have shown that the flavonoids quercetin and epicatechin are able to scavenge MGO and lower AGE formation. Objective: Data on the effects of these flavonoids on MGO and AGE concentrations in humans are not yet available. We therefore investigated the effect of quercetin and epicatechin on the concentrations of MGO and AGEs in a post hoc analysis. Methods: Thirty-seven apparently healthy, nonsmoking adults with a systolic blood pressure between 125 and 160 mm Hg at screening were included in a randomized, double-blind, placebo-controlled crossover trial. Participants ingested (-)-epicatechin (100 mg/d), quercetin 3-glucoside (160 mg/d), or placebo capsules for periods of 4 wk separated by 4-wk washout periods. Fasting blood samples were collected at the start and end of each intervention period. Liquid chromatography-tandem mass spectrometry was used to determine plasma concentrations of the dicarbonyl compounds MGO, glyoxal (GO), and 3-deoxyglucosone (3-DG) and free and protein-bound AGEs. Gene expression of glyoxalase 1 (GLO1), the enzyme involved in the degradation of MGO, was determined by either microarray or quantitative reverse transcriptase-polymerase chain reaction. Results: The treatment effect (Δtreatment - Δplacebo) of quercetin on MGO was -40.2 nmol/L (95% CI: -73.6, -6.8 nmol/L; P = 0.019), a decrease of 11% from baseline values, whereas GO, 3-DG, and free and protein-bound AGEs did not change significantly. Epicatechin did not affect the concentrations of dicarbonyls and free and protein-bound AGEs. We did not find a significant change in expression of GLO1. Conclusions: In apparently healthy (pre)hypertensive men and women, quercetin but not epicatechin decreased plasma MGO concentrations. Quercetin may potentially form a new treatment strategy for diseases in which MGO plays a pivotal role. This study was registered at clinicaltrials.gov as NCT01691404.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BB3cvntVGlsw%253D%253D&md5=177bef325087ca769c3df5710f4f6700
  20. 20
    Palma-Duran, S. A.; Lean, M. E. J.; Combet, E. Roasted Instant Coffees: Analysis of (Poly) Phenols and Melanoidins Antioxidant Capacity, Potassium and Sodium Contents. Proc. Nutr. Soc. 2016, 75, E63  DOI: 10.1017/s0029665116000537
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  21. 21
    Rufián-Henares, J. A.; Morales, F. J. A New Application of a Commercial Microtiter Plate-Based Assay for Assessing the Antimicrobial Activity of Maillard Reaction Products. Food Res. Int. 2006, 39, 33– 39,  DOI: 10.1016/j.foodres.2005.06.002
    [Crossref], [CAS], Google Scholar
    21
    A new application of a commercial microtiter plate-based assay for assessing the antimicrobial activity of Maillard reaction products
    Rufian-Henares, Jose A.; Morales, Francisco J.
    Food Research International (2005), 39 (1), 33-39CODEN: FORIEU; ISSN:0963-9969. (Elsevier B.V.)
    A new application of a com. microtiter plate-based assay was developed for the quant. screening of antimicrobial compds. formed during the thermal treatment of foods. Such compds. called Maillard reaction products (MRP) are widely distributed in the diet of western countries. The reported method is fast, cheap and easy and facilitates the generation of a dose-response curve which allows calcg. the antimicrobial activity of most substances at the same time as min. inhibitory concn. (MIC) or as oxytetracyclin equiv. value (OTEV). The test is accurate and highly reproducible (inter- and intra-day variation of 2.3% and 1.8%, resp.). For the tested samples, the higher antimicrobial activity was found in coffee melanoidins (high mol. wt. fraction of MRP) although non-covalently melanoidins-linked compds. showed antimicrobial activity too. In addn., melanoidins from more severely treated samples exerted higher inhibitory bacterial growing activity, such as CTn60 coffee (highest roasting degree) and dark beer.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXhtFWhtrvO&md5=c1c1488d4a649ba22f0c65f374b2b33d
  22. 22
    Morales, F. J.; Somoza, V.; Fogliano, V. Physiological Relevance of Dietary Melanoidins. Amino Acids 2012, 42, 1097– 1109,  DOI: 10.1007/s00726-010-0774-1
    [Crossref], [PubMed], [CAS], Google Scholar
    22
    Physiological relevance of dietary melanoidins
    Morales, Francisco J.; Somoza, Veronika; Fogliano, Vincenzo
    Amino Acids (2012), 42 (4), 1097-1109CODEN: AACIE6; ISSN:0939-4451. (SpringerWienNewYork)
    A review. Melanoidins are the final products of the Maillard reaction. The main dietary sources of melanoidins are coffee, bread crust, bakery products, black beer and cocoa. Although the chem. structures of melanoidins are widely unknown, data from gravimetric techniques allow to roughly est. a daily intake in the order of 10 g with a Western diet. Melanoidins contribute to the sensorial properties, modulating texture and flavor of foods. Growing evidence also suggests that melanoidins have health beneficial properties, such as chemopreventive, antioxidant and antimicrobial activities, and the ability to chelate different minerals. In the gastrointestinal tract, melanoidins behave not only as antioxidants, but also as dietary fiber by promoting the growth of bifidobacteria. This array of biol. activities suggests the need for anal. techniques to identify the melanoidin structures and to control their formation during thermal food processing.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XjsVWhsrw%253D&md5=4608f3bdd551881aa804e65bc42f8a4d
  23. 23
    Borrelli, R. C.; Esposito, F.; Napolitano, A.; Ritieni, A.; Fogliano, V. Characterization of a New Potential Functional Ingredient: Coffee Silverskin. J. Agric. Food Chem. 2004, 52, 1338– 1343,  DOI: 10.1021/jf034974x
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    23
    Characterization of a New Potential Functional Ingredient: Coffee Silverskin
    Borrelli, Rosa Cinzia; Esposito, Fabrizio; Napolitano, Aurora; Ritieni, Alberto; Fogliano, Vincenzo
    Journal of Agricultural and Food Chemistry (2004), 52 (5), 1338-1343CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    Dietary fiber (DF) is one of the main dietary factors contributing to consumers' well-being. In this work the possibility of using the roasted coffee silverskin (CS), a byproduct of roasted coffee beans, as a DF-rich ingredient has been evaluated. The results showed that this material has 60% total DF, with a relevant component (14%) of sol. DF. Although a small amt. of free phenol compds. is present in CS, it has a marked antioxidative activity, which can be attributed to the huge amt. of Maillard reaction products, the melanoidins. Static batch culture fermn. expts. showed that CS induces preferential growth of bifidobacteria rather than clostridia and Bacteroides spp. CS can be proposed as a new potential functional ingredient in consideration of the high content of sol. DF, the marked antioxidant activity, and the potential prebiotic activity.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXps1emsQ%253D%253D&md5=41fee00afd193a4d477582d7f0fd7c76
  24. 24
    Summa, C.; McCourt, J.; Cämmerer, B.; Fiala, A.; Probst, M.; Kun, S.; Anklam, E.; Wagner, K.-H. Radical Scavenging Activity, Anti-Bacterial and Mutagenic Effects of Cocoa Bean Maillard Reaction Products with Degree of Roasting. Mol. Nutr. Food Res. 2008, 52, 342– 351,  DOI: 10.1002/mnfr.200700403
    [Crossref], [PubMed], [CAS], Google Scholar
    24
    Radical scavenging activity, anti-bacterial and mutagenic effects of Cocoa bean Maillard Reaction products with degree of roasting
    Summa, Carmelina; McCourt, Josephine; Cammerer, Bettina; Fiala, Annette; Probst, Martina; Kun, Szillard; Anklam, Elke; Wagner, Karl-Heinz
    Molecular Nutrition & Food Research (2008), 52 (3), 342-351CODEN: MNFRCV; ISSN:1613-4125. (Wiley-VCH Verlag GmbH & Co. KGaA)
    Raw, pre-roasted and roasted Cocoa samples were sepd. into 4 different mol. wt. fractions (> 30, 30-10, 10-5 and < 5 kDa) with ultrafiltration and tested for their antibacterial, mutagenic, as well as their radical-scavenging effects. Radical-scavenging effects were tested with electro paramagnetic resonance spectroscopy, anti-mutagenicity in the Salmonella microsome assay (with and without metabolic activation), and antibacterial effects by incubating the fractions with several strains of Bifidobacteria, Enterobacter and Escherichia, and observing their growth. The radical-scavenging activity and reducing substance concns. increased, particularly in the 5-10-kDa roasted fraction. Chromaticity testing elucidated that the 10-5-kDa fraction was one of the darkest fractions. The Salmonella microsome assay showed neither mutagenic nor anti-mutagenic effects in any of the samples at any of the different concns. applied when using TA98, TA100 and TA102. All fractions reduced the growth of pathogenic bacteria, in particular at the highest concn. of 100 μg/mL; however, the same trends were also obsd. for Bifidobacteria.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXktVemu70%253D&md5=3b35098f3249ced3bdf663f3c227f6c5
  25. 25
    Fogliano, V.; Morales, F. J. Estimation of Dietary Intake of Melanoidins from Coffee and Bread. Food Funct. 2011, 2, 117– 123,  DOI: 10.1039/c0fo00156b
    [Crossref], [PubMed], [CAS], Google Scholar
    25
    Estimation of dietary intake of melanoidins from coffee and bread
    Fogliano, Vincenzo; Morales, Francisco J.
    Food & Function (2011), 2 (2), 117-123CODEN: FFOUAI; ISSN:2042-6496. (Royal Society of Chemistry)
    Melanoidins are defined as polymeric high mol. wt., brown-colored Maillard reaction end-products, contg. nitrogen. They escape digestion and pass through the upper gastrointestinal tract and can interact with the different microbial species present in the colon. Major dietary sources of melanoidins are coffee and bread crust. Both coffee and bread crust melanoidins can be fermented by the human hindgut microflora thus sharing some of the properties attributed to dietary fiber. Despite the emerging pos. physiol. properties of such dietary constituents their intake has not been estd. yet. To this aim melanoidin content in different type of coffee brews, bread and dry biscuits was detd. by sequential ultrafiltration and enzymic digestion. Despite some drawbacks and limiting steps in the calcn., such as the lack of a ref. material, an educated guess on the dietary intake of melanoidins has been put forward. Data indicated that the intake of coffee melanoidins ranged between 0.5 to 2.0 g per day for moderate and heavy consumers, resp. For bread and dry biscuits an intake in the ranges of 1.8-15.0 and 3.2-8.5 g per day has been calcd. These figures suggest that a realistic estn. of melanoidins dietary intake for general population would be close to 10 g per day considering all the possible alimentary sources.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhs1yltr0%253D&md5=39cd9f122ab2840e7d15a059aecf4c7a
  26. 26
    Nunes, F. M.; Coimbra, M. A. Chemical Characterization of the High Molecular Weight Material Extracted with Hot Water from Green and Roasted Arabica Coffee. J. Agric. Food Chem. 2001, 49, 1773– 1782,  DOI: 10.1021/jf0012953
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    26
    Chemical Characterization of the High Molecular Weight Material Extracted with Hot Water from Green and Roasted Arabica Coffee
    Nunes, Fernando M.; Coimbra, Manuel A.
    Journal of Agricultural and Food Chemistry (2001), 49 (4), 1773-1782CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    The polysaccharides present in coffee infusions are known to contribute to the organoleptic characteristics of the drink, such as the creamy sensation perceived in the mouth known as "body", the release of aroma substances, and the stability of espresso coffee foam. To increase the knowledge about the origin, compn., and structure of the polysaccharide fraction, the high mol. wt. material (HMWM) was extd. with hot water from 2 green and roasted ground arabica coffees: Costa Rica (wet processed) and Brazil (dry processed). The polysaccharides present in the green coffees HMWM were arabinogalactans (62%), galactomannans (24%), and glucans, and those found in roasted coffees were galactomannans (69%) and arabinogalactans (28%). The polysaccharides of the HMWM of the roasted coffees were less branched than those of the green coffees. The major green coffee proteins had mol. wts. of 58 and 38 kDa, and the 58 kDa protein had two subunits, of 38 and 20 kDa, possibly linked by disulfide bonds. The protein fraction obtained from roasted coffees had only a defined band with ≤14 kDa and a diffuse band with >200 kDa. The majority of the galactomannans were pptd. with solns. of 50% ethanol, and the size-exclusion chromatog. of the roasted fractions showed Co-elution of polysaccharides, proteins, phenolics, and brown compds. The use of strong hydrogen and hydrophobic dissocn. conditions allowed us to conclude that the phenolics and brown compds. were linked by covalent bonds to the polymeric material.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXhsFKhur8%253D&md5=541c8b6305d1404560c915b2090d709b
  27. 27
    Summa, C.; Raposo, F. C.; McCourt, J.; Scalzo, R. L.; Wagner, K.-H.; Elmadfa, I.; Anklam, E. Effect of Roasting on the Radical Scavenging Activity of Cocoa Beans. Eur. Food Res. Technol. 2006, 222, 368– 375,  DOI: 10.1007/s00217-005-0005-2
    [Crossref], [CAS], Google Scholar
    27
    Effect of roasting on the radical scavenging activity of cocoa beans
    Summa, Carmelina; Raposo, Fernando Cordeiro; McCourt, Josephine; Lo Scalzo, Roberto; Wagner, Karl-Heinz; Elmadfa, Ibrahim; Anklam, Elke
    European Food Research and Technology (2006), 222 (3-4), 368-375CODEN: EFRTFO; ISSN:1438-2377. (Springer GmbH)
    The free-radical scavenging activity of cocoa samples subjected to different roasting treatments was detd. The samples (raw, pre-roasted and roasted) were sepd. into 4 mol. wt. fractions per sample (>30, 30-10, 10-5, and <5 kDa). The free-radical scavenging activity was detd. with the DPPH• (1,1-dipheny-2-picrylhydrazyl), and ABTS•+ [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] free-radical scavenging assays for all samples. Both tests were compared in terms of sensitivity and measurement precision, at different reaction times. Comparing the results from each test, the free-radical scavenging activity trends were similar for each fraction but with notable differences in the sensitivity of the assays. Anal. of the concn. of reducing substances, such as water sol. phenolics, melanoidins, carbohydrates, etc, in these fractions by the photometric Folin-Ciocalteu assay, showed a similar pattern to the free-radical scavenging activity trend. Moreover, this comparison showed that there were significantly (P < 0.05) more reducing substances and free-radical scavenging activity in the 10-5 kDa roasted cocoa bean fraction.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28Xht1Cnu7o%253D&md5=d6c232f1d39a0a9ef5c0bf717ff90d2d
  28. 28
    Borrelli, R. C.; Mennella, C.; Barba, F.; Russo, M.; Russo, G. L.; Krome, K.; Erbersdobler, H. F.; Faist, V.; Fogliano, V. Characterization of Coloured Compounds Obtained by Enzymatic Extraction of Bakery Products. Food Chem. Toxicol. 2003, 41, 1367– 1374,  DOI: 10.1016/s0278-6915(03)00140-6
    [Crossref], [PubMed], [CAS], Google Scholar
    28
    Characterization of coloured compounds obtained by enzymatic extraction of bakery products
    Borrelli, R. C.; Mennella, C.; Barba, F.; Russo, M.; Russo, G. L.; Krome, K.; Erbersdobler, H. F.; Faist, V.; Fogliano, V.
    Food and Chemical Toxicology (2003), 41 (10), 1367-1374CODEN: FCTOD7; ISSN:0278-6915. (Elsevier Science B.V.)
    Melanoidins, the brown-colored polymers formed through Maillard type reaction in several heat-treated foods, represent a significant part of our diet, with an av. intake of grams per day. Most of the studies on the physiol. effects of these compds. have been performed using the water sol. melanoidin fractions. But dietary melanoidins formed on the surface of bakery products are poorly sol. in water as well as in org. solvents. An enzymic solubilization procedure was developed on a gluten-glucose model system and it was applied to bread and biscuits. The sol. material obtained was tested for its antioxidant activity, for its effect on phase-I and phase-II xenobiotic enzymes and for potential cytotoxic effects. Sol. melanoidins from model system and biscuits exhibit a strong antioxidant activity and do not show any cytotoxicity on Caco-2 cells. Melanoidins extd. from biscuits was able to inhibit the activity of Phase I (NADPH-cytochrome-c reductase) and Phase II (Glutathione-S-transferase) enzymes, whereas the low mol. wt. melanoidins isolated from gluten-glucose model system inhibit the activity of NADPH-cytochrome-c reductase.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXlvFGhsL0%253D&md5=efc9f599aae89afaba9a2bfc67475bcc
  29. 29
    Glomb, M. A.; Tschirnich, R. Detection of α-Dicarbonyl Compounds in Maillard Reaction Systems and in Vivo. J. Agric. Food Chem. 2001, 49, 5543– 5550,  DOI: 10.1021/jf010148h
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    29
    Detection of α-Dicarbonyl Compounds in Maillard Reaction Systems and in Vivo
    Glomb, Marcus A.; Tschirnich, Roswitha
    Journal of Agricultural and Food Chemistry (2001), 49 (11), 5543-5550CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    α-Dicarbonyl compds. are of major interest in food chem. and biochem. as important precursors of, for example, protein modifications and flavor. Due to their high reactivity most of the published structures were identified and quantitated as stable derivs. after reaction with trapping reagents. However, the present study showed for the 1st time that the trapping reagents are of dramatic impact on the final qual. and quant. α-dicarbonyl spectrum. As important representatives, aminoguanidine and o-phenylenediamine were used to compare trapping characteristics and to monitor the dicarbonyl structures arising from the degrdn. of an Amadori compd. Dicarbonyl structures with a reductone moiety could not be or were only insufficiently detected by slow-reacting reagents such as aminoguanidine. On the other hand, fast-reacting chems. such as o-phenylenediamine imposed high oxidative stress on the investigated system and led to enhanced or false pos. formation of dicarbonyl compds. generated by oxidative pathways.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXnvVOltrs%253D&md5=55122455d9fb9d35594acbd8bf060060
  30. 30
    Hellwig, M.; Gensberger-Reigl, S.; Henle, T.; Pischetsrieder, M. Food-Derived 1,2-Dicarbonyl Compounds and Their Role in Diseases. Seminars in Cancer Biology; Elsevier, 2018; Vol. 49, pp 1– 8.
    [Crossref], Google Scholar
    There is no corresponding record for this reference.
  31. 31
    Delgado-Andrade, C.; Morales, F. J. Unraveling the Contribution of Melanoidins to the Antioxidant Activity of Coffee Brews. J. Agric. Food Chem. 2005, 53, 1403– 1407,  DOI: 10.1021/jf048500p
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    31
    Unraveling the contribution of melanoidins to the antioxidant activity of coffee brews
    Delgado-Andrade, Cristina; Morales, Francisco J.
    Journal of Agricultural and Food Chemistry (2005), 53 (5), 1403-1407CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    Instant coffees produced from the same green coffee beans were supplied from a company in different roasting degrees, light, medium, and dark. Melanoidins were obtained by ultrafiltration (10 kDa) and subsequent diafiltration. Pure melanoidins were isolated from melanoidins after overnight incubation in 2 M NaCl. The antioxidant activities of instant coffees, melanoidins, and pure melanoidins were tested using the conjugated diene formation from a 2,2'-azobis(2-amidinopropane) dihydrochloride-induced linoleic acid oxidn. in an aq. system. No significant differences were found between melanoidins and pure melanoidins with different roasting degrees. Therefore, the contribution of the pure melanoidin fraction to the total antioxidant activity of melanoidins was significantly lower. More than 50% of the antioxidant activity of melanoidins is due to low mol. wt. compds. linked non-covalently to the melanoidin skeleton. A new concept of the overall antioxidant properties of food melanoidins is described, where chelating ability toward low mol. wt. antioxidant compds. is connected to the stabilization of these compds. involved in the shelf life of the product.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXhtFegsbY%253D&md5=71b9723d18d86e229381bf7be2f91144
  32. 32
    Oracz, J.; Nebesny, E.; Żyżelewicz, D. Identification and Quantification of Free and Bound Phenolic Compounds Contained in the High-Molecular Weight Melanoidin Fractions Derived from Two Different Types of Cocoa Beans by UHPLC-DAD-ESI-HR-MSn. Food Res. Int. 2019, 115, 135– 149,  DOI: 10.1016/j.foodres.2018.08.028
    [Crossref], [PubMed], [CAS], Google Scholar
    32
    Identification and quantification of free and bound phenolic compounds contained in the high-molecular weight melanoidin fractions derived from two different types of cocoa beans by UHPLC-DAD-ESI-HR-MSn
    Oracz, Joanna; Nebesny, Ewa; Zyzelewicz, Dorota
    Food Research International (2019), 115 (), 135-149CODEN: FORIEU; ISSN:0963-9969. (Elsevier B.V.)
    The aim of the present study was to establish the profiles of sol. free phenolics (SFPs) and bound phenolics (BPs) in high mol. wt. (HMW) melanoidin fractions isolated from raw and roasted beans of two Theobroma cacao L. varieties. Samples were prepd. using three methods (saline treatment and acidic and alk. hydrolysis) to obtain different forms of phenolic compds. A total of fifteen phenolics, including three flavan-3-ols, seven phenolic acids, one phenolic aldehyde, and four N-phenylpropenoyl-L-amino acids (NPAs), were identified using ultra-high-performance liq. chromatog. coupled to diode array detection and electrospray ionization high-resoln. mass spectrometry (UHPLC-DAD-ESI-HR-MSn). In HMW fractions from both studied cocoa types, the main SFPs were N-caffeoyl-L-Asp and procyanidin B2, whereas the main BPs were catechin, epicatechin, ellagic acid, protocatechualdehyde, and N-caffeoyl-L-Asp. The concns. of individual BPs were much higher than the content of total SFPs. It was also found that, as compared to alk. hydrolysis, acid hydrolysis released a significantly higher amt. of BPs from HMW melanoidin fractions. A comprehensive quant. anal. indicated significant variation in the investigated phenolic compds. depending on the cocoa type and roasting conditions. An increase in treatment temp. from 110 to 150 °C led to a decline in SFPs and an increment in BPs. The HMW fractions of unroasted Criollo beans exhibited the highest content of SFPs and the lowest content of BPs. The highest BP concns. were obtained for both cocoa bean varieties roasted at 150 °C. The present study revealed that HMW melanoidin fractions from cocoa beans of different varieties roasted at higher temps. are a good source of phenolic compds. that can be released under both acidic and alk. conditions.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhsFCjtr7F&md5=80997c7cfa41efb888ea9d1d18d78e29
  33. 33
    Coelho, C.; Ribeiro, M.; Cruz, A. C. S.; Domingues, M. R. M.; Coimbra, M. A.; Bunzel, M.; Nunes, F. M. Nature of Phenolic Compounds in Coffee Melanoidins. J. Agric. Food Chem. 2014, 62, 7843– 7853,  DOI: 10.1021/jf501510d
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    33
    Nature of Phenolic Compounds in Coffee Melanoidins
    Coelho, Carina; Ribeiro, Miguel; Cruz, Ana C. S.; Domingues, M. Rosario M.; Coimbra, Manuel A.; Bunzel, Mirko; Nunes, Fernando M.
    Journal of Agricultural and Food Chemistry (2014), 62 (31), 7843-7853CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    Phenolic compds. are incorporated into coffee melanoidins during roasting mainly in condensed form (42-62 mmol/100 g) and also in ester-linked form (1.1-1.6 mmol/100 g), with incorporation levels depending on the green coffee chlorogenic acid content. The phenolic compds. are incorporated in different coffee melanoidin populations, but mainly in those sol. in 75% ethanol (82%), a significant correlation between the amt. of phenolic compds. and the amt. of protein and color characteristics of the different melanoidin populations being obsd. The incorporation of phenolic compds. into coffee melanoidins is a significant pathway of chlorogenic acid degrdn. during roasting, representing 23% of the chlorogenic acids lost. These account for the nearly 26% of the material not accounted for by polysaccharides and proteins present in coffee melanodins. The cleavage mechanism and the efficiency of alk. fusion used to release condensed phenolics from coffee melanoidins suggest that the phenolic compds. can be linked to the polymeric material by aryl-ether, stilbene type, and/or biphenyl linkages.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFShs7fP&md5=2395e80cf0ff96142064ad4e40d4d4ed
  34. 34
    Fernandez-Gomez, B.; Ullate, M.; Picariello, G.; Ferranti, P.; Mesa, M. D.; del Castillo, M. D. New Knowledge on the Antiglycoxidative Mechanism of Chlorogenic Acid. Food Funct. 2015, 6, 2081– 2090,  DOI: 10.1039/c5fo00194c
    [Crossref], [PubMed], [CAS], Google Scholar
    34
    New knowledge on the antiglycoxidative mechanism of chlorogenic acid
    Fernandez-Gomez, Beatriz; Ullate, Monica; Picariello, Gianluca; Ferranti, Pasquale; Mesa, Maria Dolores; del Castillo, Maria Dolores
    Food & Function (2015), 6 (6), 2081-2090CODEN: FFOUAI; ISSN:2042-6496. (Royal Society of Chemistry)
    The role of chlorogenic acid (CGA) in the formation of advanced glycation end-products (AGEs) (glycoxidn. reaction) was studied. Model systems composed of bovine serum albumin (BSA) (1 mg mL-1) and methylglyoxal (5 mM) under mimicked physiol. conditions (pH 7.4, 37 °C) were used to evaluate the antiglycoxidative effect of CGA (10 mM). The stability of CGA under reaction conditions was assayed by HPLC and MALDI-TOF MS. The glycoxidn. reaction was estd. by anal. of free amino groups by the OPA assay, spectral anal. of fluorescent AGEs and total AGEs by ELISA, and color formation by absorbance at 420 nm. Structural changes in protein were evaluated by anal. of phenol bound to the protein backbone using the Folin reaction, UV-Vis spectral anal. and MALDI-TOF-MS, while changes in protein function were measured by detg. the antioxidant capacity using the ABTS radical cation decolorisation assay. CGA was isomerized and oxidized under our exptl. conditions. Evidence of binding between BSA and multiple CGA and/or its deriv. mols. (isomers and oxidn. products) was found. CGA inhibited (p < 0.05) the formation of fluorescent and total AGEs at 72 h of reaction by 91.2 and 69.7%, resp. The binding of phenols to BSA significantly increased (p < 0.001) its antioxidant capacity. Correlations between free amino group content, phenol bound to protein and antioxidant capacity were found. Results indicate that CGA simultaneously inhibits the formation of potentially harmful compds. (AGEs) and promotes the generation of neoantioxidant structures.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXotlKjtbk%253D&md5=9874dedc1f770b2603386361d40b6f97
  35. 35
    Meade, S. J.; Miller, A. G.; Gerrard, J. A. The Role of Dicarbonyl Compounds in Non-Enzymatic Crosslinking: A Structure-Activity Study. Bioorg. Med. Chem. 2003, 11, 853– 862,  DOI: 10.1016/s0968-0896(02)00564-3
    [Crossref], [PubMed], [CAS], Google Scholar
    35
    The role of dicarbonyl compounds in non-enzymatic crosslinking: a structure-activity study
    Meade, Susie J.; Miller, Antonia G.; Gerrard, Juliet A.
    Bioorganic & Medicinal Chemistry (2003), 11 (6), 853-862CODEN: BMECEP; ISSN:0968-0896. (Elsevier Science Ltd.)
    The Maillard reaction is a complex network of reactions that has been shown to result in the non-enzymic crosslinking of proteins. Recent attention has focussed on the role of α-dicarbonyl compds. as important in vivo contributors to protein crosslinking but, despite extensive research, the mol. mechanisms of the crosslinking reaction remain open to conjecture. In particular, no relationship between the structure of the carbonyl-contg. compds. and their activity as crosslinking agents has been established. In an effort to elucidate a structure-reactivity relationship, a wide range of dicarbonyl compds., including linear, cyclic, di-aldehyde and di-ketone compds., were reacted with the model protein RNase A and their crosslinking activity assessed. Methylglyoxal and glutaraldehyde were found to be the most efficient crosslinkers, while closely related mols. effected crosslinking at a much lower rate. Cyclopentan-1,2-dione was also shown to be a reactive crosslinking agent. The efficiency of methylglyoxal and glutaraldehyde at crosslinking is thought to be related to their ability to form stable heterocyclic compds. that are the basis of protein crosslinks. The reasons for the striking reactivity of these two compds., compared to closely related structures is explained by subtle balances between competing pathways in a complex reaction network.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXhsVCitL8%253D&md5=46f3ae8dc852bbf2ef46fd50abdfc842
  36. 36
    Voziyan, P. A.; Metz, T. O.; Baynes, J. W.; Hudson, B. G. A Post-Amadori Inhibitor Pyridoxamine Also Inhibits Chemical Modification of Proteins by Scavenging Carbonyl Intermediates of Carbohydrate and Lipid Degradation. J. Biol. Chem. 2002, 277, 3397– 3403,  DOI: 10.1074/jbc.m109935200
    [Crossref], [PubMed], [CAS], Google Scholar
    36
    A post-Amadori inhibitor pyridoxamine also inhibits chemical modification of proteins by scavenging carbonyl intermediates of carbohydrate and lipid degradation
    Voziyan, Paul A.; Metz, Thomas O.; Baynes, John W.; Hudson, Billy G.
    Journal of Biological Chemistry (2002), 277 (5), 3397-3403CODEN: JBCHA3; ISSN:0021-9258. (American Society for Biochemistry and Molecular Biology)
    Reactive carbonyl compds. are formed during autoxidn. of carbohydrates and peroxidn. of lipids. These compds. are intermediates in the formation of advanced glycation end products (AGE) and advanced lipoxidn. end products (ALE) in tissue proteins during aging and in chronic disease. We studied the reaction of carbonyl compds. glyoxal (GO) and glycolaldehyde (GLA) with pyridoxamine (PM), a potent post-Amadori inhibitor of AGE formation in vitro and of development of renal and retinal pathol. in diabetic animals. PM reacted rapidly with GO and GLA in neutral, aq. buffer, forming a Schiff base intermediate that cyclized to a hemiaminal adduct by intramol. reaction with the phenolic hydroxyl group of PM. This bicyclic intermediate dimerized to form a five-ring compd. with a central piperazine ring, which was characterized by electrospray ionization-liq. chromatog./mass spectrometry, NMR, and x-ray crystallog. PM also inhibited the modification of lysine residues and loss of enzymic activity of RNase in the presence of GO and GLA and inhibited formation of the AGE/ALE Nε-(carboxymethyl)lysine during reaction of GO and GLA with bovine serum albumin. Our data suggest that the AGE/ALE inhibitory activity and the therapeutic effects of PM obsd. in diabetic animal models depend, at least in part, on its ability to trap reactive carbonyl intermediates in AGE/ALE formation, thereby inhibiting the chem. modification of tissue proteins.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XhtVaktrw%253D&md5=311b3afcfb1e69474b1b24841f2afa3d
  37. 37
    Rogalla, P.; Lembcke, A.; Rückert, J. C.; Hein, E.; Bollow, M.; Rogalla, N. E.; Hamm, B. Spasmolysis at CT Colonography: Butyl Scopolamine versus Glucagon. Radiology 2005, 236, 184– 188,  DOI: 10.1148/radiol.2353040007
    [Crossref], [PubMed], [CAS], Google Scholar
    37
    Spasmolysis at CT colonography: butyl scopolamine versus glucagon
    Rogalla Patrik; Lembcke Alexander; Ruckert Jens C; Hein Eike; Bollow Matthias; Rogalla Noga E; Hamm Bernd
    Radiology (2005), 236 (1), 184-8 ISSN:0033-8419.
    PURPOSE: To retrospectively determine if the use of butyl scopolamine or glucagon in the supine patient improves colonic distention and reduces the number of collapsed intestinal segments at computed tomographic (CT) colonography. MATERIALS AND METHODS: This study had institutional review board approval; subject informed consent was not required. CT colonography was performed without the administration of an intravenous spasmolytic in 80 asymptomatic subjects (group 1; 45 women, 35 men; age range, 48-77 years; mean, 61.9 years). These subjects were matched with two groups of 80 subjects who were similar in age but were premedicated with glucagon (group 2; 41 women, 39 men; age range, 43-76 years; mean, 63.1 years) or butyl scopolamine (group 3; 43 women, 37 men; age range, 34-77 years; mean, 63.4 years). All 240 subjects were examined in the supine position with multisection CT and a section thickness of 1 mm after intravenous contrast agent administration and rectal carbon dioxide insufflation. The colon was divided into seven segments, and the colon length, total volume, radial distensibility, and number of non-distended segments were calculated for each subject and compared among the three groups. Statistical analysis was performed with analysis of variance and chi2 testing. RESULTS: Mean bowel length was not significantly different among the groups. Mean colon volumes and radial distensibilities, respectively, were 1.84 L and 3.69 cm in group 1, 2.14 L and 3.98 cm in group 2, and 2.35 L and 4.23 cm in group 3; differences in colon volume and radial distensibility were significant only between group 1 and group 3 (P < .001). At CT colonography, 29 segments in 20 group 1 subjects were collapsed, 23 segments in 12 group 2 subjects were collapsed, and 11 segments in six group 3 subjects were collapsed (P = .016). CONCLUSION: Premedication with butyl scopolamine or, less effectively, glucagon improves colonic distention in the supine subject.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BD2MzjslGjsA%253D%253D&md5=758a7119bdf0144e76668ba5d3be8745
  38. 38
    Vitaglione, P.; Fogliano, V.; Pellegrini, N. Coffee, Colon Function and Colorectal Cancer. Food Funct. 2012, 3, 916– 922,  DOI: 10.1039/c2fo30037k
    [Crossref], [PubMed], [CAS], Google Scholar
    38
    Coffee, colon function and colorectal cancer
    Vitaglione, Paola; Fogliano, Vincenzo; Pellegrini, Nicoletta
    Food & Function (2012), 3 (9), 916-922CODEN: FFOUAI; ISSN:2042-6496. (Royal Society of Chemistry)
    A review. For several years the physiol. effects of coffee have been focused on its caffeine content, disregarding the hundreds of bioactive coffee components, such as polyphenols, melanoidins, carbohydrates, diterpenes, etc. These compds. may exert their protection against colorectal cancer (CRC), the third most common cancer worldwide. However, the amt. and type of compds. ingested with the beverage may be highly different depending on the variety of coffee used, the roasting degree, the type of brewing method as well as the serving size. In this frame, this paper reviews the mechanisms by which coffee may influence the risk of CRC development focusing on espresso and filtered coffee, as well as on the components that totally or partially reach the colon i.e. polyphenols and dietary fiber, including melanoidins. In particular the effects of coffee on some colon conditions whose deregulation may lead to cancer, namely microbiota compn. and lumen reducing environment, were considered. Taken together the discussed studies indicated that, due to their in vivo metab. and compn., both coffee chlorogenic acids and dietary fiber, including melanoidins, may reduce CRC risk, increasing colon motility and antioxidant status. Further studies should finally assess whether the coffee benefits for colon are driven through a prebiotic effect.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xht1GjurjL&md5=521f154d06ef6ff1fe7060bf0513a4a2
  39. 39
    Mesías, M.; Navarro, M.; Martínez-Saez, N.; Ullate, M.; del Castillo, M. D.; Morales, F. J. Antiglycative and Carbonyl Trapping Properties of the Water Soluble Fraction of Coffee Silverskin. Food Res. Int. 2014, 62, 1120– 1126,  DOI: 10.1016/j.foodres.2014.05.058
    [Crossref], [CAS], Google Scholar
    39
    Antiglycative and carbonyl trapping properties of the water soluble fraction of coffee silverskin
    Mesias, M.; Navarro, M.; Martinez-Saez, N.; Ullate, M.; del Castillo, M. D.; Morales, F. J.
    Food Research International (2014), 62 (), 1120-1126CODEN: FORIEU; ISSN:0963-9969. (Elsevier B.V.)
    Carbonyl stress and accumulation of advanced glycation end-products (AGEs) in human tissues are involved in diabetic complications, atherosclerosis, Alzheimer's disease and aging. The objective of this study was to evaluate the in vitro protective effect of aq. exts. of coffee silverskin (CS) in the formation of AGEs and trapping of carbonyl reactive species such as methylglyoxal (MGO). Aq. exts. of CS from Arabica and Robusta coffee varieties were obtained under environment friendly extn. conditions. CS exts. were characterized by the anal. of dietary fiber, caffeine, chlorogenic acids (CGAs), total phenolic compds., browning, melanoidins, and antioxidant capacity. CS exts. and CGA exhibited a dose-dependent anti-AGE capacity in the protein-glucose model system (37 °C/21 days) with an IC50 of 0.6 mg/mL and 0.4 mg/mL, resp. Caffeine did not prevent AGE formation under the studied conditions. Regardless to protein-MGO assay (37 °C/14 days), the anti-AGE capacity of CS exts. and CGA was also dose-dependent with an IC50 of 1.3 mg/mL and 0.1 mg/mL, resp. Caffeine weakly inhibited the reaction of protein and MGO. The MGO trapping capacity was established as a model for protection against carbonyl stress. Robusta CS was very effective for the direct trapping of MGO with an IC50 of 0.055 mg/mL as compared with Arabica CS (IC50 of 0.6 mg/mL). CGA and caffeine showed an IC50 for MGO trapping capacity of 0.14 mg/mL and > 10 mg/mL, resp. The highest CGA content in the Robusta CS ext. could explain its higher MGO trapping activity as compared with the Arabica CS ext. The anti-AGE and MGO trapping capacities of CS may be assocd. to other chem. components besides CGA. In conclusion, aq. CS ext. may be considered as a natural source of inhibitors of in vitro formation of AGEs and carbonyl stress. The inhibitory effect of the coffee exts. may be assocd. to their carbonyl trapping capacity.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFSqsbjF&md5=14b280e48f840cdfc842bb4b832b2261
  40. 40
    Yoon, S.-R.; Shim, S.-M. Inhibitory Effect of Polyphenols in Houttuynia Cordata on Advanced Glycation End-Products (AGEs) by Trapping Methylglyoxal. LWT-Food Sci. Technol. 2015, 61, 158– 163,  DOI: 10.1016/j.lwt.2014.11.014
    [Crossref], [CAS], Google Scholar
    40
    Inhibitory effect of polyphenols in Houttuynia cordata on advanced glycation end-products (AGEs) by trapping methylglyoxal
    Yoon, So-Ra; Shim, Soon-Mi
    LWT--Food Science and Technology (2015), 61 (1), 158-163CODEN: LSTWB3; ISSN:0023-6438. (Elsevier Ltd.)
    The inhibitory effect of bioactive components from Houttuynia cordata (H. cordata) on advanced glycation end-products (AGEs) by trapping methylglyoxal (MGO) was investigated. MGO and its adducts of quercitrin, chlorogenic acid, rutin was analyzed by using liq. chromatog.-mass spectrometry (LC-MS/MSn). The remaining MGO were 52.3, 26.7, and 9.4% for chlorogenic acid, quercitrin, and rutin, resp. and the mono- or di-MGO conjugated adducts of quercitrin and rutin were identified at 24 h of reaction. The formation of AGEs was detected through the reaction of glucose with protein by the fluorescence method. During the glycation reaction, quercitrin, rutin, and methanol ext. of H. cordata decreased the prodn. level of AGEs by 91-94.6 %. H. cordata contg. chlorogenic acid, quercitrin, and rutin may have potential role in minimizing AGEs formation.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvFGisrnP&md5=da001678ca5431ba31156f1bf65988c2
  41. 41
    Moreira, A. S. P.; Nunes, F. M.; Domingues, M. R.; Coimbra, M. A. Coffee Melanoidins: Structures, Mechanisms of Formation and Potential Health Impacts. Food Funct. 2012, 3, 903– 915,  DOI: 10.1039/c2fo30048f
    [Crossref], [PubMed], [CAS], Google Scholar
    41
    Coffee melanoidins: structures, mechanisms of formation and potential health impacts
    Moreira, Ana S. P.; Nunes, Fernando M.; Domingues, M. Rosario; Coimbra, Manuel A.
    Food & Function (2012), 3 (9), 903-915CODEN: FFOUAI; ISSN:2042-6496. (Royal Society of Chemistry)
    A review. During the roasting process, coffee bean components undergo structural changes leading to the formation of melanoidins, which are defined as high mol. wt. nitrogenous and brown-colored compds. As coffee brew is one of the main sources of melanoidins in the human diet, their health implications are of great interest. In fact, several biol. activities, such as antioxidant, antimicrobial, anticariogenic, anti-inflammatory, antihypertensive, and antiglycative activities, have been attributed to coffee melanoidins. To understand the potential of coffee melanoidin health benefits, it is essential to know their chem. structures. The studies undertaken to date dealing with the structural characterization of coffee melanoidins have shown that polysaccharides, proteins, and chlorogenic acids are involved in coffee melanoidin formation. However, exact structures of coffee melanoidins and mechanisms involved in their formation are far from being elucidated. This paper systematizes the available information and provides a crit. overview of the knowledge obtained so far about the structure of coffee melanoidins, mechanisms of their formation, and their potential health implications.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xht1GjurjM&md5=c0d1aaa5d8d68e29fb305c81a264085d
  42. 42
    Xie, C.; Yu, K.; Zhong, D.; Yuan, T.; Ye, F.; Jarrell, J. A.; Millar, A.; Chen, X. Investigation of Isomeric Transformations of Chlorogenic Acid in Buffers and Biological Matrixes by Ultraperformance Liquid Chromatography Coupled with Hybrid Quadrupole/Ion Mobility/Orthogonal Acceleration Time-of-Flight Mass Spectrometry. J. Agric. Food Chem. 2011, 59, 11078– 11087,  DOI: 10.1021/jf203104k
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    42
    Investigation of Isomeric Transformations of Chlorogenic Acid in Buffers and Biological Matrixes by Ultraperformance Liquid Chromatography Coupled with Hybrid Quadrupole/Ion Mobility/Orthogonal Acceleration Time-of-Flight Mass Spectrometry
    Xie, Cen; Yu, Kate; Zhong, Dafang; Yuan, Tao; Ye, Fei; Jarrell, Joseph Andy; Millar, Alan; Chen, Xiaoyan
    Journal of Agricultural and Food Chemistry (2011), 59 (20), 11078-11087CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    Ultraperformance liq. chromatog. coupled with hybrid quadrupole/ion mobility/orthogonal acceleration time-of-flight (oa-TOF) mass spectrometry (UPLC-IM-MS) was used to study the isomeric transformations of trans-5-caffeoylquinic acid, an extremely active compd. present in multiple vegetables, fruits, and beverages. The UPLC/oa-TOF MS results proved that in phosphate buffer (pH 7.4), plasma, or urine sample, trans-5-caffeoylquinic acid first isomerizes to trans-4-caffeoylquinic acid and then to trans-3-caffeoylquinic acid by intramol. acyl migration. When exposed to UV light, trans-3-, -4-, and -5-caffeoylquinic acids undergo cis/trans isomerization to form cis isomers. The isomerization was solely dependent on the pH of the matrix, as well as the incubation temp., and was independent of metabolic enzymes. UPLC-IM-MS results revealed that a reversible cis/trans isomerization of caffeoylquinic acids could also be induced by the elec. field in an electrospray source. Thus, understanding the possible role of elec. field-induced isomerization of caffeoylquinic acids may help lessen the confusion between gas phase phenomena and liq. state chem. when applying IM-MS anal. The comprehensive understanding of caffeoylquinic acid isomerization transformations is crucial for the appropriate handling of samples and interpretation of exptl. data.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXht1GgtbzF&md5=17a4d4f709c8ddc10e67bb7238495fb0
  43. 43
    Moreira, A. S. P.; Nunes, F. M.; Simões, C.; Maciel, E.; Domingues, P.; Domingues, M. R. M.; Coimbra, M. A. Transglycosylation Reactions, a Main Mechanism of Phenolics Incorporation in Coffee Melanoidins: Inhibition by Maillard Reaction. Food Chem. 2017, 227, 422– 431,  DOI: 10.1016/j.foodchem.2017.01.107
    [Crossref], [PubMed], [CAS], Google Scholar
    43
    Transglycosylation reactions, a main mechanism of phenolics incorporation in coffee melanoidins: Inhibition by Maillard reaction
    Moreira, Ana S. P.; Nunes, Fernando M.; Simoes, Cristiana; Maciel, Elisabete; Domingues, Pedro; Domingues, M. Rosario M.; Coimbra, Manuel A.
    Food Chemistry (2017), 227 (), 422-431CODEN: FOCHDJ; ISSN:0308-8146. (Elsevier Ltd.)
    Under roasting conditions, polysaccharides depolymerize and also are able to polymerize, forming new polymers through non-enzymic transglycosylation reactions (TGRs). TGRs can also occur between carbohydrates and aglycons, such as the phenolic compds. present in daily consumed foods like coffee. In this study, glycosidically-linked phenolic compds. were quantified in coffee melanoidins, the polymeric nitrogenous brown-colored compds. formed during roasting, defined as end-products of Maillard reaction. One third of the phenolics present were in glycosidically-linked form. In addn., the roasting of solid-state mixts. mimicking coffee beans compn. allowed the conclusion that proteins play a regulatory role in TGRs extension and, consequently, modulate melanoidins compn. Overall, the results obtained showed that TGRs are a main mechanism of phenolics incorporation in melanoidins and are inhibited by amino groups through Maillard reaction.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXitVylurs%253D&md5=094a554b5d059120023be51a40fecccd
  44. 44
    Nunes, F. M.; Coimbra, M. A. Melanoidins from Coffee Infusions. Fractionation, Chemical Characterization, and Effect of the Degree of Roast. J. Agric. Food Chem. 2007, 55, 3967– 3977,  DOI: 10.1021/jf063735h
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    44
    Melanoidins from Coffee Infusions. Fractionation, Chemical Characterization, and Effect of the Degree of Roast
    Nunes, Fernando M.; Coimbra, Manuel A.
    Journal of Agricultural and Food Chemistry (2007), 55 (10), 3967-3977CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    A method involving fractionation in ethanol aq. solns., anion exchange chromatog., and immobilized copper chelating chromatog. was developed to obtain high mol. wt. anionic melanoidin populations from coffee infusions. Six anionic fractions with different physicochem. properties (ethanol soly. and chelating ability) and chem. compn. regarding carbohydrate as well as protein nature and content were isolated. Fractions with similar chem. compn. were obtained for light-, medium-, and dark-roasted coffee infusions. These melanoidin fractions accounted for 30-33% of the cold-water sol. high mol. wt. material, independently of the degree of roast in coffee. The nature and abundance of the different polysaccharides in each fraction were dependent on their ethanol soly. The 50% ethanol insol. melanoidin populations contained mostly galactomannan-like carbohydrates, and the fractions obtained with 75% ethanol contained mostly arabinogalactan-like carbohydrates. The melanoidin populations with chelating properties presented significantly lower carbohydrate content and, from these, the 75% ethanol sol. fractions were almost devoid of carbohydrate material. The results obtained suggest that the chelating ability of these coffee melanoidins is modulated by their carbohydrates.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXksFSnsL0%253D&md5=4eeeb1807dcfa24ab5763967dfe9f311
  45. 45
    Monente, C.; Ludwig, I. A.; Irigoyen, A.; De Peña, M.-P.; Cid, C. Assessment of Total (Free and Bound) Phenolic Compounds in Spent Coffee Extracts. J. Agric. Food Chem. 2015, 63, 4327– 4334,  DOI: 10.1021/acs.jafc.5b01619
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    45
    Assessment of Total (Free and Bound) Phenolic Compounds in Spent Coffee Extracts
    Monente, Carmen; Ludwig, Iziar A.; Irigoyen, Angel; De Pena, Maria-Paz; Cid, Concepcion
    Journal of Agricultural and Food Chemistry (2015), 63 (17), 4327-4334CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    Spent coffee is the main byproduct of the brewing process and a potential source of bioactive compds., mainly phenolic acids easily extd. with water. Free and bound caffeoylquinic (3-CQA, 4-CQA, 5-CQA), dicaffeoylquinic (3,4-diCQA, 3,5-diCQA, 4,5-diCQA), caffeic, ferulic, p-coumaric, sinapic, and 4-hydroxybenzoic acids were measured by HPLC, after the application of three treatments (alk., acid, saline) to spent coffee exts. Around 2-fold higher content of total phenolics has been estd. in comparison to free compds. Phenolic compds. with one or more caffeic acid mols. were approx. 54% linked to macromols. such as melanoidins, mainly by noncovalent interactions (up to 81% of bound phenolic compds.). The rest of the quantitated phenolic acids were mainly attached to other structures by covalent bonds (62-97% of total bound compds.). Alk. hydrolysis and saline treatment were suitable to est. total bound and ionically bound phenolic acids, resp., whereas acid hydrolysis is an inadequate method to quantitate coffee phenolic acids.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXms1OgsLc%253D&md5=ec5ceebfd00716ea903a700ad7b3da07
  46. 46
    Vitaglione, P.; Napolitano, A.; Fogliano, V. Cereal Dietary Fibre: A Natural Functional Ingredient to Deliver Phenolic Compounds into the Gut. Trends Food Sci. Technol. 2008, 19, 451– 463,  DOI: 10.1016/j.tifs.2008.02.005
    [Crossref], [CAS], Google Scholar
    46
    Cereal dietary fibre: a natural functional ingredient to deliver phenolic compounds into the gut
    Vitaglione, Paola; Napolitano, Aurora; Fogliano, Vincenzo
    Trends in Food Science & Technology (2008), 19 (9), 451-463CODEN: TFTEEH; ISSN:0924-2244. (Elsevier Ltd.)
    A review. Epidemiol. studies assoc. whole grain consumption with a reduced risk of many diseases. This paper focuses on the antioxidant component of cereal dietary fiber starting from its chem. structure, bioavailability and biol. meaning. By the crit. assessment of the intervention studies performed using cereal bran and whole grains, the hypothesis that the slow and continuous release in the gut of the dietary fiber bound antioxidants dets. the health benefits, is illustrated. In the last part of the work, new perspectives and technol. possibilities to enhance the health potential of this cereal component are also highlighted.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXptVWqsrw%253D&md5=0dda35cf84b89b8a54c860f39228275b
  47. 47
    Saura-Calixto, F. Antioxidant Dietary Fiber Product: A New Concept and a Potential Food Ingredient. J. Agric. Food Chem. 1998, 46, 4303– 4306,  DOI: 10.1021/jf9803841
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    47
    Antioxidant Dietary Fiber Product: A New Concept and a Potential Food Ingredient
    Saura-Calixto, Fulgencio
    Journal of Agricultural and Food Chemistry (1998), 46 (10), 4303-4306CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    The main characteristics of a natural product, antioxidant dietary fiber (ADF), rich in both dietary fiber (DF) and polyphenolic compds. (PP), obtained from red grape pomace is described. Both nonextractable proanthocyanidins (28.6%) and extractable polyphenols (2.0%) are assocd. with the dietary fiber matrix. The antioxidant capacity of this product was detd. in vitro by lipid oxidn. inhibition (LOI) and free radical scavenging (FRE) procedures. One gram of the product showed similar LOI and FRE effects as 400 mg and 100 mg of DL-α-tocopherol, resp. Extractable PP of grape ADF showed higher antioxidant capacity than red wine PP. The physiol. and nutritional significance of ADF is discussed and the requirements of vegetable materials to be considered as ADF is proposed.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1cXmtV2gtbk%253D&md5=653a71cf769037571a87ad781b257104
  48. 48
    López-Galilea, I.; Andueza, S.; Leonardo, I. d.; Paz de Peña, M.; Cid, C. Influence of Torrefacto Roast on Antioxidant and Pro-Oxidant Activity of Coffee. Food Chem. 2006, 94, 75– 80,  DOI: 10.1016/j.foodchem.2004.10.052
    [Crossref], [CAS], Google Scholar
    48
    Influence of torrefacto roast on antioxidant and pro-oxidant activity of coffee
    Lopez-Galilea, Isabel; Andueza, Susana; di Leonardo, Isabella; Paz de Pena, M.; Cid, Concepcion
    Food Chemistry (2005), 94 (1), 75-80CODEN: FOCHDJ; ISSN:0308-8146. (Elsevier B.V.)
    The addn. of sugar at the end of the torrefacto roasting process may influence the antioxidant and pro-oxidant properties of coffee because sugar is one of the main precursors the Maillard reaction. The aim of the work was to study and to compare the antioxidant and pro-oxidant properties of some com. roasted coffees which are selected to represent conventional roasted arabica coffee and arabica/robusta blends, and torrefacto roasted blends. Higher antioxidant activity was obsd. in Colombian coffees than in conventional roasted coffee blends. On the other hand, when the percentage of torrefacto coffee was increased, an increase of the antioxidant activity and a slight tendency to decrease the pro-oxidant activity were obsd. Moreover, principal component anal. allowed sepn. of: (a) brands by PC1 (46.9%), characterized by color parameters defined by roasting degree and (b) torrefacto roasted blends by PC2 (33.7%), characterized by antioxidant/pro-oxidant activity.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXlvV2rsbs%253D&md5=654748126cf95329b720305e35cb4881
  49. 49
    Rufián-Henares, J. A.; Morales, F. J. Effect of in Vitro Enzymatic Digestion on Antioxidant Activity of Coffee Melanoidins and Fractions. J. Agric. Food Chem. 2007, 55, 10016– 10021,  DOI: 10.1021/jf0718291
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    49
    Effect of in vitro enzymatic digestion on antioxidant activity of coffee melanoidins and fractions
    Rufian-Henares, Jose A.; Morales, Francisco J.
    Journal of Agricultural and Food Chemistry (2007), 55 (24), 10016-10021CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    Traditionally antioxidant activity of melanoidins has only been evaluated in food for implication in shelf life but gastrointestinal digestion is necessary to study their potential bioactivity. In addn., the biol. fate of melanoidins has been stressed during the past decade since they did not behave as inert substances. In the present paper a sol. coffee melanoidin isolated from brewed coffee after ultrafiltration with a 10 kDa cutoff membrane was treated ionically and enzymically collecting the resp. high and low mol. wt. fractions. Antioxidant activity of these fractions was evaluated with five well-described assays (DPPH, ABTS, ORAC, HOSC, and FRAP) that were previously setup in a plate reader based automatized anal. Low mol. wt. compds. released from melanoidin after gastrointestinal digestion exerted the highest antioxidant activity, even higher than compds. bound ionically to melanoidins. Gastrointestinal digestion is able to modify coffee melanoidins to some extent, as hypothesized from their abs. antioxidant activities. Two options are plausible: by modifying/releasing the ionically bound compds. and/or by genesis of new more active structures from the melanoidin skeleton after enzymic treatment.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXht1alsbfE&md5=703af6a2c2a09477b4facbd3053d1396
  50. 50
    Borrelli, R. C.; Visconti, A.; Mennella, C.; Anese, M.; Fogliano, V. Chemical Characterization and Antioxidant Properties of Coffee Melanoidins. J. Agric. Food Chem. 2002, 50, 6527– 6533,  DOI: 10.1021/jf025686o
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    50
    Chemical Characterization and Antioxidant Properties of Coffee Melanoidins
    Borrelli, Rosa Cinzia; Visconti, Attilio; Mennella, Carmela; Anese, Monica; Fogliano, Vincenzo
    Journal of Agricultural and Food Chemistry (2002), 50 (22), 6527-6533CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    Melanoidins, the brown polymers formed through Maillard reaction during coffee roasting, constitute up to 25% of the coffee beverages' dry matter. In this study chem. characterization of melanoidins obtained from light-, medium-, and dark-roasted coffee beans, manufd. from the same starting material, was performed. Melanoidins were sepd. by gel filtration chromatog. and studied by MALDI-TOF mass spectrometry. Results showed that the amt. of melanoidins present in the brews increased as the intensity of the thermal treatment increased, while their mol. wt. decreased. The antioxidant activity of melanoidins isolated from the different brews was studied by using different methodologies. Melanoidins antiradical activity detd. by ABTS•+ and DMPD•+ assays decreased as the intensity of roasting increased, but the ability to prevent linoleic acid peroxidn. was higher in the dark-roasted samples. Data suggest that melanoidins must be carefully considered when the relevance of coffee intake in human health is studied.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XntFegs7Y%253D&md5=3ee4c0dbe7fbb89e61fb6e5a5a1cb33b
  51. 51
    Dittrich, R.; Dragonas, C.; Kannenkeril, D.; Hoffmann, I.; Mueller, A.; Beckmann, M. W.; Pischetsrieder, M. A Diet Rich in Maillard Reaction Products Protects LDL against Copper Induced Oxidation Ex Vivo, a Human Intervention Trial. Food Res. Int. 2009, 42, 1315– 1322,  DOI: 10.1016/j.foodres.2009.04.007
    [Crossref], [CAS], Google Scholar
    51
    A diet rich in Maillard reaction products protects LDL against copper induced oxidation ex vivo, a human intervention trial
    Dittrich, R.; Dragonas, C.; Kannenkeril, D.; Hoffmann, I.; Mueller, A.; Beckmann, M. W.; Pischetsrieder, M.
    Food Research International (2009), 42 (9), 1315-1322CODEN: FORIEU; ISSN:0963-9969. (Elsevier B.V.)
    Maillard reaction products (MRPs) have antioxidative properties in vitro but the influence of a diet rich in MRPs on oxidative damage in vivo remains unknown. In this study, the influence of thermally processed foods rich in MRPs on copper induced oxidn. of human low-d. lipoprotein (LDL) in vitro was examd. Moreover, oxidative resistance of LDL (OR) in blood plasma of eight healthy subjects was monitored, who consumed diets poor and rich in MRPs in weekly turn for 3 wk. Dark beer, bread crust, and roasted coffee led to a statistically significant increased OR in vitro compared to pale beer, bread crumb, and raw coffee. The consumption of a diet rich in MRPS significantly increased plasma OR compared to the diet poor in MRPs by 35.5%. This study indicates that thermally processed foods rich in MRPs inhibit the LDL oxidn. in vitro and have the ability to reduce oxidative modification of LDL in vivo.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtVSisbnF&md5=680902b7e4445b05aa993a9b9bcf1f56
  52. 52
    Wu, Z.-J.; Ma, X.-L.; Fang, D.-M.; Qi, H.-Y.; Ren, W.-J.; Zhang, G.-L. Analysis of Caffeic Acid Derivatives from Osmanthus Yunnanensis Using Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry. Eur. J. Mass Spectrom. 2009, 15, 415– 429,  DOI: 10.1255/ejms.992
    [Crossref], [PubMed], [CAS], Google Scholar
    52
    Analysis of caffeic acid derivatives from Osmanthus yunnanensis using electrospray ionization quadrupole time-of-flight mass spectrometry
    Wu, Zhi-Jun; Ma, Xiao-Li; Fang, Dong-Mei; Qi, Hua-Yi; Ren, Wei-Jian; Zhang, Guo-Lin
    European Journal of Mass Spectrometry (2009), 15 (3), 415-429CODEN: EJMSCL; ISSN:1469-0667. (IM Publications)
    A series of six caffeic acid derivs. (1-6) in Osmanthus yunnanensis were investigated by electrospray quadrupole time-of-flight tandem mass spectrometry (ESI-QToF-MS/MS) in both neg.- and pos.-ion modes. High-quality MS/MS spectra of [M + H]+ are generated from high-abundance protonated parent ions obtained by addn. of ammonium chloride to the solns. Fragmentation mechanisms of [M - H]- and [M + H]+ precursor ions were proposed and elemental compns. of most of the product ions were confirmed on the basis of the high-resoln. ESI-collision-induced dissocn. (CID)-MS/MS spectra. It was found that the fragment ions at m/z 179, m/z 161, m/z 135 and m/z 134 in neg.-ion mode and at m/z 163, m/z 145 and m/z 135 in pos. mode should be the characteristic ions of caffeic acid. In addn., the radical fragment ions with high abundance were obsd. for many caffeic acid derivs. esp. for 4. The structural elements of unknown compds. 7 and 8 were tentatively identified on based on tandem mass spectra of known ones.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXmtV2gs7Y%253D&md5=5bb61c2aa010deeba2ea3452e03acc0b
  53. 53
    Totlani, V. M.; Peterson, D. G. Epicatechin Carbonyl-Trapping Reactions in Aqueous Maillard Systems: Identification and Structural Elucidation. J. Agric. Food Chem. 2006, 54, 7311– 7318,  DOI: 10.1021/jf061244r
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    53
    Epicatechin Carbonyl-Trapping Reactions in Aqueous Maillard Systems: Identification and Structural Elucidation
    Totlani, Vandana M.; Peterson, Devin G.
    Journal of Agricultural and Food Chemistry (2006), 54 (19), 7311-7318CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    Recently, the group reported via labeling expts. that epicatechin in Maillard reaction aq. glucose-glycine model systems formed adduct reaction products with C2, C3, and C4 sugar fragments. In the current study, the identity of the sugar fragment precursors responsible for adduct generation by directly comparing the liq. chromatog.-mass spectrometry properties of these reported epicatechin (EC)-sugar fragments adducts with those generated from reactions consisting of only EC and well-known Maillard-generated glucose fragments (i.e., glyoxal, glycolaldehyde, methylglyoxal, glyceraldehyde, etc.) was investigated. The structural properties of an EC-methylglyoxal adduct reaction product were also analyzed by NMR. The most likely precursors for the C2, C3, and C4 sugar moiety of the EC-sugar fragment adducts were identified as glyoxal, hydroxyacetone, and erythrose, resp. 1H NMR anal. of the EC-methylglyoxal indicated that the analyte underwent rapid conformational/constitutional exchange. Using cold temp. (-25 °C) two-dimensional NMR analyses (heteronuclear multiple bond coherence, heteronuclear multiple quantum coherence, and 1H-1H correlation spectroscopy), the structure of one of the isomers was reported to consist of a covalent linkage between the C1 position of the methylglyoxal and either the C6 or the C8 position of the EC A ring, presumably generated by hydroxyalkylation and arom. substitution reactions.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28Xoslaksb4%253D&md5=a94bd8c133d30be87c67fdea155c230a
  54. 54
    Lo, C.-Y.; Hsiao, W.-T.; Chen, X.-Y. Efficiency of Trapping Methylglyoxal by Phenols and Phenolic Acids. J. Food Sci. 2011, 76, H90– H96,  DOI: 10.1111/j.1750-3841.2011.02067.x
    [Crossref], [PubMed], [CAS], Google Scholar
    54
    Efficiency of trapping methylglyoxal by phenols and phenolic acids
    Lo, Chih-Yu; Hsiao, Wen-Tuan; Chen, Xiu-Yu
    Journal of Food Science (2011), 76 (3), H90-H96CODEN: JFDSAZ; ISSN:0022-1147. (Wiley-Blackwell)
    The carbonyl stress that leads to the formation of advanced glycation end products (AGEs) has drawn much attention recently because of its micro- and macrovascular implications. During monitoring of methylglyoxal (MG), the efficiency of phenolics to directly trap MG can be demonstrated. Twenty compds. consisting of a single benzene ring structure with the addn. of at least one hydroxyl group were allowed to react with MG at 37 °C for 1 h under physiol. conditions in pH 7.4 phosphate buffer soln. Compds. composed of a benzene structure with a mono-hydroxyl substitute cannot react with MG. Among benzenediols and di-hydroxyl benzoic acids, only hydroquinone reacted with MG and showed a 13% decrease in MG. Nevertheless, high reactivity was shown for 3 benzenetriols. The percentages of MG remaining were 45%, 51%, and 36% for pyrogallol, 1,2,4-trihydroxybenzene, and 1,3,5-trihydroxybenzene, resp. When a carboxyl group is added to the benzenetriols, steric hindrance and carbon electron charges on benzene ring are the influential factors in reactivity. Using computational chem. calcns., a carbon electron charge of -0.24 was the min. value for high reactivity.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXlt1Sit7w%253D&md5=61dfc8fa0f46322c6598df6eb60e8bde
  55. 55
    Shao, X.; Chen, H.; Zhu, Y.; Sedighi, R.; Ho, C.-T.; Sang, S. Essential Structural Requirements and Additive Effects for Flavonoids to Scavenge Methylglyoxal. J. Agric. Food Chem. 2014, 62, 3202– 3210,  DOI: 10.1021/jf500204s
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    55
    Essential Structural Requirements and Additive Effects for Flavonoids to Scavenge Methylglyoxal
    Shao, Xi; Chen, Huadong; Zhu, Yingdong; Sedighi, Rashin; Ho, Chi-Tang; Sang, Shengmin
    Journal of Agricultural and Food Chemistry (2014), 62 (14), 3202-3210CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    Reactive dicarbonyl species, such as methylglyoxal (MGO), are considered as the major precursors of advanced glycation end products (AGEs), which are believed to be one of the physiol. causes of diabetes and its complications. Scavenging of reactive dicarbonyl species using naturally occurring flavonoids has been proposed as an effective way to prevent diabetic complications. To elucidate the structural requirements of flavonoids in scavenging MGO, seven flavonoids (quercetin, luteolin, epicatechin, genistein, daidzein, apigenin, and phloretin) and five sub-components of the flavonoids (gallic acid, phloroglucinol, pyrogallol, pyrocatechol, and resorcinol) were examd. in this study. The results showed: (1) 1,2,3-trihydroxybenzene (pyrogallol) has higher MGO-scavenging activity than 1,3,5-trihydroxybenzene and 1,2- and 1,3-dihydroxybenzene, and substitution at position 5 of pyrogallol diminished the scavenging activity, indicating that position 5 is the active site of pyrogallol; (2) the A ring is the active site of flavonoids in contributing the MGO-trapping efficacy, and the hydroxyl group at C-5 on the A ring enhances the trapping efficacy; (3) the double bond between C-2 and C-3 on the C ring could facilitate the trapping efficacy; and (4) the no. of hydroxyl groups on the B ring does not significantly influence the trapping efficacy. In addn., the authors found there is an additive effect in MGO trapping by two common flavonoids, quercetin and phloretin, indicating that flavonoid-enriched foods and beverages may be used to prevent the development of diabetic complications.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXkslSgsLk%253D&md5=3a65956cd71c4019be5192a0d507756b
  56. 56
    Hidalgo, F. J.; Aguilar, I.; Zamora, R. Model Studies on the Effect of Aldehyde Structure on Their Selective Trapping by Phenolic Compounds. J. Agric. Food Chem. 2017, 65, 4736– 4743,  DOI: 10.1021/acs.jafc.7b01081
    [ACS Full Text ACS Full Text], [CAS], Google Scholar
    56
    Model Studies on the Effect of Aldehyde Structure on Their Selective Trapping by Phenolic Compounds
    Hidalgo, Francisco J.; Aguilar, Isabel; Zamora, Rosario
    Journal of Agricultural and Food Chemistry (2017), 65 (23), 4736-4743CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
    The reaction among flavor-relevant satd. aldehydes (propanal, 2-methylpropanal, butanal, 2-methylbutanal, 3-methylbutanal, pentanal, hexanal, and glyoxal) and phenolic compds. (resorcinol, 2-methylresorcinol, 2,5-dimethylresorcinol, and orcinol) was studied both to identify and characterize the formed carbonyl-phenol adducts and to understand the differences in the carbonyl-trapping abilities of phenolic compds. The obtained results showed that carbonyl-trapping by phenolics is selective and the formation of carbonyl-phenol adducts depends on the structure of both phenol and aldehyde involved. In relation to the phenolic deriv., the presence of groups that increase the nucleophilicity of phenolic carbons will increase the carbonyl-trapping ability of these compds. On the other hand, the presence of groups that increase the steric hindrance of these positions without affecting nucleophilia, will inhibit the reaction. Analogously, the presence of branching at position 2 of the aldehyde will also inhibit the reaction by steric hindrance. All these results suggest that addn. of phenolics to foods may change food flavor not only because of their sensory properties but also because they can modify the ratio among food odorants by selective reaction of phenolics with detd. carbonyl compds.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXotFOkt70%253D&md5=231b3f0d7a6e0ad682e6c5ba65e4dd13
  57. 57
    Capuano, E.; Oliviero, T.; van Boekel, M. A. J. S. Modeling Food Matrix Effects on Chemical Reactivity: Challenges and Perspectives. Crit. Rev. Food Sci. Nutr. 2018, 58, 2814– 2828,  DOI: 10.1080/10408398.2017.1342595
    [Crossref], [PubMed], [CAS], Google Scholar
    57
    Modeling food matrix effects on chemical reactivity: Challenges and perspectives
    Capuano, Edoardo; Oliviero, Teresa; van Boekel, Martinus A. J. S.
    Critical Reviews in Food Science and Nutrition (2018), 58 (16), 2814-2828CODEN: CRFND6; ISSN:1040-8398. (Taylor & Francis, Inc.)
    The same chem. reaction may be different in terms of its position of the equil. (i.e., thermodn.) and its kinetics when studied in different foods. The diversity in the chem. compn. of food and in its structural organization at macro-, meso-, and microscopic levels, i.e., the food matrix, is responsible for this difference. In this viewpoint paper, the multiple, and interconnected ways the food matrix can affect chem. reactivity are summarized. Moreover, mechanistic and empirical approaches to explain and predict the effect of food matrix on chem. reactivity are described. Mechanistic models aim to quantify the effect of food matrix based on a detailed understanding of the chem. and phys. phenomena occurring in food. Their applicability is limited at the moment to very simple food systems. Empirical modeling based on machine learning combined with data-mining techniques may represent an alternative, useful option to predict the effect of the food matrix on chem. reactivity and to identify chem. and phys. properties to be further tested. In such a way the mechanistic understanding of the effect of the food matrix on chem. reactions can be improved.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsVarsL3F&md5=1f79e27bfbee53ae850df9ee8a1612ac

Cited By

This article is cited by 30 publications.

  1. Ruth Fabiola Peña-Correa, Burçe Ataç Mogol, Christos Fryganas, Vincenzo Fogliano. Fluidized-Bed-Roasted Cocoa Has Different Chemical Characteristics than Conventionally Roasted Cocoa. Journal of Agricultural and Food Chemistry 2023, 71 (26) , 10203-10211. https://doi.org/10.1021/acs.jafc.3c01678
  2. Jilu Feng, Karin Schroën, Sylvain Guyot, Agnès Gacel, Vincenzo Fogliano, Claire C. Berton-Carabin. Physical and Oxidative Stabilization of Oil-In-Water Emulsions by Roasted Coffee Fractions: Interface- and Continuous Phase-Related Effects. Journal of Agricultural and Food Chemistry 2023, 71 (11) , 4717-4728. https://doi.org/10.1021/acs.jafc.2c07365
  3. Heping Cui, Ziyan Wang, Mengyu Ma, Khizar Hayat, Qiang Zhang, Yan Xu, Xiaoming Zhang, Chi-Tang Ho. Maillard Browning Inhibition by Ellagic Acid via Its Adduct Formation with the Amadori Rearrangement Product. Journal of Agricultural and Food Chemistry 2021, 69 (34) , 9924-9933. https://doi.org/10.1021/acs.jafc.1c03481
  4. Rosario Zamora, Cristina M. Lavado-Tena, Francisco J. Hidalgo. Identification of Precursors and Formation Pathway for the Heterocyclic Aromatic Amine 2-Amino-3-methylimidazo(4,5-f)quinoline (IQ). Journal of Agricultural and Food Chemistry 2020, 68 (28) , 7474-7481. https://doi.org/10.1021/acs.jafc.0c02869
  5. Fernanda Machado, Manuel A. Coimbra, Maria Dolores del Castillo, Filipe Coreta-Gomes. Mechanisms of action of coffee bioactive compounds – a key to unveil the coffee paradox. Critical Reviews in Food Science and Nutrition 2023, 137 , 1-23. https://doi.org/10.1080/10408398.2023.2221734
  6. Jilu Feng, Claire C. Berton-Carabin, Sylvain Guyot, Agnès Gacel, Vincenzo Fogliano, Karin Schroën. Coffee melanoidins as emulsion stabilizers. Food Hydrocolloids 2023, 139 , 108522. https://doi.org/10.1016/j.foodhyd.2023.108522
  7. Shahid Adeel, Fazal-Ur Rehman, Ayesha Amin, Nimra Amin, Fatima Batool, Atya Hassan, Meral Ozomay. Sustainable exploration of coffee extracts ( coffea arabica l. ) for dyeing of microwave-treated bio-mordanted cotton fabric. Pigment & Resin Technology 2023, 52 (3) , 331-340. https://doi.org/10.1108/PRT-02-2022-0024
  8. Slim Blidi, Antonio Dario Troise, Moira Ledbetter, Sarah Cottin, Keith Sturrock, Sabrina De Pascale, Andrea Scaloni, Alberto Fiore. α-Dicarbonyl compounds trapping ability and antiglycative effect of high-molecular-weight brewer's spent grain melanoidins. LWT 2023, 180 , 114679. https://doi.org/10.1016/j.lwt.2023.114679
  9. Jinxin Li, Hao Zhang, Xijuan Yang, Ling Zhu, Gangcheng Wu, Hui Zhang. The fiber-bound polyphenols from highland barley with inhibitory effects against carbonyls during in vitro digestion of cookies and French fries. Food Bioscience 2023, 5 , 102685. https://doi.org/10.1016/j.fbio.2023.102685
  10. Joanna Oracz, Monika Prejzner, Joanna Grzelczyk, Gabriela Kowalska, Dorota Żyżelewicz. Bioactive Compounds, Antioxidant Activity and Sensory Properties of Northern Red Oak (Quercus rubra L., syn. Q. borealis F. Michx) Seeds Affected by Roasting Conditions. Molecules 2023, 28 (5) , 2299. https://doi.org/10.3390/molecules28052299
  11. Marlene Machado, Helena Ferreira, M. Beatriz P. P. Oliveira, Rita C. Alves. Coffee by-products: An underexplored source of prebiotic ingredients. Critical Reviews in Food Science and Nutrition 2023, 24 , 1-20. https://doi.org/10.1080/10408398.2023.2181761
  12. Alessandro La Mantia, Federica Ianni, Aurélie Schoubben, Marco Cespi, Klemen Lisjak, Davide Guarnaccia, Roccaldo Sardella, Paolo Blasi. Effect of Cocoa Roasting on Chocolate Polyphenols Evolution. Antioxidants 2023, 12 (2) , 469. https://doi.org/10.3390/antiox12020469
  13. Qiuhui Zhang, Moutong Chen, Teodora Emilia Coldea, Huirong Yang, Haifeng Zhao. Structure, chemical stability and antioxidant activity of melanoidins extracted from dark beer by acetone precipitation and macroporous resin adsorption. Food Research International 2023, 164 , 112045. https://doi.org/10.1016/j.foodres.2022.112045
  14. Nadia Cruz, Marcos Flores, Inés Urquiaga, Felipe Ávila. Modulation of 1,2-Dicarbonyl Compounds in Postprandial Responses Mediated by Food Bioactive Components and Mediterranean Diet. Antioxidants 2022, 11 (8) , 1513. https://doi.org/10.3390/antiox11081513
  15. Ghassan Faisal Mohsin, Franz-Josef Schmitt, Clemens Kanzler, Azalldeen Kazal Alzubaidi, Andrea Hornemann. How alanine catalyzes melanoidin formation and dehydration during synthesis from glucose. European Food Research and Technology 2022, 248 (6) , 1615-1624. https://doi.org/10.1007/s00217-022-03989-x
  16. Jinxin Li, Hao Zhang, Xijuan Yang, Ling Zhu, Gangcheng Wu, Xiguang Qi, Hui Zhang. Trapping of reactive carbonyl species by fiber-bound polyphenols from whole grains under simulated physiological conditions. Food Research International 2022, 156 , 111142. https://doi.org/10.1016/j.foodres.2022.111142
  17. Jéssica Petrine Castro Pereira, Fernanda Aparecida Castro Pereira, Carlos José Pimenta. Benefits of Coffee Consumption for Human Health: An Overview. Current Nutrition & Food Science 2022, 18 (4) , 387-397. https://doi.org/10.2174/1573401318666220111151531
  18. Min Chen, Hua Zhou, Caihuan Huang, Pengzhan Liu, Jia Fei, Juanying Ou, Shiyi Ou, Jie Zheng. Identification and cytotoxic evaluation of the novel rutin–methylglyoxal adducts with dione structures in vivo and in foods. Food Chemistry 2022, 377 , 132008. https://doi.org/10.1016/j.foodchem.2021.132008
  19. Jilu Feng, Claire C. Berton-Carabin, Vincenzo Fogliano, Karin Schroën. Maillard reaction products as functional components in oil-in-water emulsions: A review highlighting interfacial and antioxidant properties. Trends in Food Science & Technology 2022, 121 , 129-141. https://doi.org/10.1016/j.tifs.2022.02.008
  20. Mei Zhi Alcine Chan, Shao-Quan Liu. Coffee brews as food matrices for delivering probiotics: Opportunities, challenges, and potential health benefits. Trends in Food Science & Technology 2022, 119 , 227-242. https://doi.org/10.1016/j.tifs.2021.11.030
  21. Kim Maasen, Simone JPM Eussen, Jean LJM Scheijen, Carla JH van der Kallen, Pieter C Dagnelie, Antoon Opperhuizen, Coen DA Stehouwer, Marleen MJ van Greevenbroek, Casper G Schalkwijk. Higher habitual intake of dietary dicarbonyls is associated with higher corresponding plasma dicarbonyl concentrations and skin autofluorescence: the Maastricht Study. The American Journal of Clinical Nutrition 2022, 115 (1) , 34-44. https://doi.org/10.1093/ajcn/nqab329
  22. Anna Marina Grigoriou, Eftychia Pinakoulaki. Linking the Dynamic Changes in the In Vitro Antioxidant Activity of Carob Kibbles upon Roasting to the Chemical and Structural Changes Revealed by FTIR Spectroscopy. Antioxidants 2021, 10 (12) , 2025. https://doi.org/10.3390/antiox10122025
  23. Zhisong Wang, Shaopeng Li, Zhujun Zhang, Xianglong Zhang, Ting Xia, Yu Zheng, Menglei Xia, Min Wang. Exploring polymerisation of 1,2-dicarbonyl compounds to decipher the formation of nitrogen-free substructures in melanoidins. European Polymer Journal 2021, 161 , 110859. https://doi.org/10.1016/j.eurpolymj.2021.110859
  24. Qiaozhi Zhang, Zhijie Huang, Yong Wang, Yanbo Wang, Linglin Fu, Laijin Su. Chinese bayberry (Myrica rubra) phenolics mitigated protein glycoxidation and formation of advanced glycation end-products: A mechanistic investigation. Food Chemistry 2021, 361 , 130102. https://doi.org/10.1016/j.foodchem.2021.130102
  25. Mei Zhi Alcine Chan, Yuyun Lu, Shao-Quan Liu. In vitro bioactivities of coffee brews fermented with the probiotics Lacticaseibacillus rhamnosus GG and Saccharomyces boulardii CNCM-I745. Food Research International 2021, 149 , 110693. https://doi.org/10.1016/j.foodres.2021.110693
  26. Zhisong Wang, Zhujun Zhang, Shaopeng Li, Xianglong Zhang, Menglei Xia, Ting Xia, Min Wang. Formation mechanisms and characterisation of the typical polymers in melanoidins from vinegar, coffee and model experiments. Food Chemistry 2021, 355 , 129444. https://doi.org/10.1016/j.foodchem.2021.129444
  27. Heping Cui, Junhe Yu, Yun Zhai, Linhui Feng, Pusen Chen, Khizar Hayat, Yan Xu, Xiaoming Zhang, Chi-Tang Ho. Formation and fate of Amadori rearrangement products in Maillard reaction. Trends in Food Science & Technology 2021, 115 , 391-408. https://doi.org/10.1016/j.tifs.2021.06.055
  28. Hao Zhang, Antonio Dario Troise, Yajing Qi, Gangcheng Wu, Hui Zhang, Vincenzo Fogliano. Insoluble dietary fibre scavenges reactive carbonyl species under simulated physiological conditions: The key role of fibre-bound polyphenols. Food Chemistry 2021, 349 , 129018. https://doi.org/10.1016/j.foodchem.2021.129018
  29. Slađana Žilić, Işıl Gürsul Aktağ, Dejan Dodig, Vural Gökmen. Investigations on the formation of Maillard reaction products in sweet cookies made of different cereals. Food Research International 2021, 144 , 110352. https://doi.org/10.1016/j.foodres.2021.110352
  30. Hao Zhang, Antonio Dario Troise, Hui Zhang, Vincenzo Fogliano. Cocoa melanoidins reduce the formation of dietary advanced glycation end-products in dairy mimicking system. Food Chemistry 2021, 345 , 128827. https://doi.org/10.1016/j.foodchem.2020.128827
Download PDF

  • Abstract

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 1

    Figure 1. GO, MGO, and DA trapping capacities of HMW-CM, HMW-COM, and HMW-BM with different concentrations (0.01–2.5 mg/mL) and PM (0.108 mg/mL) at 168 h. Results are expressed as mean ± SD for n = 3. Bars with the same letter are not significantly different according to Tukey’s HSD test at p > 0.05.

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 2

    Figure 2. Dicarbonyl trapping capacity of HMW-CM (1.0 mg/mL), HMW-COM (1.0 mg/mL), and PM (0.108 mg/mL) within 2 h under simulated physiological conditions. The concentration of DCs and melanoidins was calculated according to the estimated daily intake. Results are expressed as mean ± SD for n = 3. Bars with the same letter are not significantly different according to Tukey’s HSD test at p > 0.05.

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 3

    Figure 3. Time-course of GO (A), MGO (B), and DA (C) trapping capacity of PM (0.108 mg/mL), HWM-CM (2 mg/mL), CA (0.115 mg/mL), and 3-CQA (0.227 mg/mL). Results are expressed as mean ± SD for n = 3.

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 4

    Figure 4. GO, MGO, and DA trapping capacities of nontreated, saline-treated, acidic- and alkaline-hydrolyzed HMW-CM after 168 h incubation. Results are expressed as mean ± SD for n = 3. Different letters indicate significant differences according to Tukey’s HSD test at p > 0.05.

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 5

    Figure 5. Total ion chromatogram of the CA (A) and CA–MGO (B) systems after incubation at 37 °C for 3 days, extracted ion chromatogram [M – H]− of mono-MGO–CA adduct [m/z, 251, (C)] and di-MGO–CA adduct [m/z, 323, (D)], and MS/MS spectra of CA (E), mono-MGO–CA adduct (F), and di-MGO–CA adduct (G).

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 6

    Figure 6. Proposed mechanism of reaction for trapping of MGO by CA under simulated physiological conditions.

    High Resolution Image
    Download MS PowerPoint Slide

  • References

    ARTICLE SECTIONS
    Jump To

    This article references 57 other publications.

    1. 1
      Smuda, M.; Glomb, M. A. Fragmentation Pathways during Maillard-Induced Carbohydrate Degradation. J. Agric. Food Chem. 2013, 61, 10198– 10208,  DOI: 10.1021/jf305117s
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      1
      Fragmentation pathways during Maillard-induced carbohydrate degradation
      Smuda, Mareen; Glomb, Marcus A.
      Journal of Agricultural and Food Chemistry (2013), 61 (43), 10198-10208CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      A review. The Maillard reaction network with focus on the chem. of dicarbonyl structures causes considerable interest of research groups in food chem. and medical science, resp. Dicarbonyl compds. are well established as the central intermediates in the nonenzymic browning reaction and have been verified to be responsible for advanced glycation endproduct (AGE) formation. A multitude of Maillard dicarbonyls covering the range of the intact carbon backbone down to C3 and C2 fragments were detected in several carbohydrate systems, for example, in glucose, maltose, or ascorbic acid reactions. By definition, dicarbonyls with a C2-C5 carbon backbone must originate by fission of the original carbon skeleton. The present review deals with the five major mechanisms reported in the literature for dicarbonyl decompn.: (i) retro-aldol fragmentation, (ii) hydrolytic α-dicarbonyl cleavage, (iii) oxidative α-dicarbonyl cleavage, (iv) hydrolytic β-dicarbonyl cleavage, and (v) amine-induced β-dicarbonyl cleavage.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXivVWgsrc%253D&md5=35e66a63d971683e9b73747f2dac5019
    2. 2
      Thornalley, P. J.; Langborg, A.; Minhas, H. S. Formation of Glyoxal, Methylglyoxal and 8-Deoxyglucosone in the Glycation of Proteins by Glucose. Biochem. J. 1999, 344, 109– 116,  DOI: 10.1042/bj3440109
      [Crossref], [PubMed], [CAS], Google Scholar
      2
      Formation of glyoxal, methylglyoxal and 3-deoxyglucosone in the glycation of proteins by glucose
      Thornalley, Paul J.; Langborg, Annika; Minhas, Harjit S.
      Biochemical Journal (1999), 344 (1), 109-116CODEN: BIJOAK; ISSN:0264-6021. (Portland Press Ltd.)
      The glycation of proteins by glucose has been linked to the development of diabetic complications and other diseases. Early glycation is thought to involve the reaction of glucose with N-terminal and lysyl side chain amino groups to form Schiff's base and fructosamine adducts. The formation of the α-oxoaldehydes, glyoxal, methylglyoxal and 3-deoxyglucosone, in early glycation was investigated. Glucose (50 mM) degraded slowly at pH 7.4 and 37°C to form glyoxal, methylglyoxal and 3-deoxyglucosone throughout a 3-wk incubation period. Addn. of t-BOC-lysine and human serum albumin increased the rate of formation of α-oxoaldehydes - except glyoxal and methylglyoxal concns. were low with albumin, as expected from the high reactivity of glyoxal and methylglyoxal with arginine residues. The degrdn. of fructosyl-lysine also formed glyoxal, methylglyoxal and 3-deoxyglucosone. α-Oxoaldehyde formation was dependent on the concn. of phosphate buffer and availability of trace metal ions. This suggests that α-oxoaldehydes were formed in early glycation from the degrdn. of glucose and Schiff's base adduct. Since α-oxoaldehydes are important precursors of advanced glycation adducts, these adducts may be formed from early and advanced glycation processes. Short periods of hyperglycemia, as occur in impaired glucose tolerance, may be sufficient to increase the concns. of α-oxoaldehydes in vivo.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1MXns1yjtrY%253D&md5=ba9ad4d19d895cb31724d48dfeaeac8a
    3. 3
      Hollnagel, A.; Kroh, L. W. Formation of α-Dicarbonyl Fragments from Mono- and Disaccharides under Caramelization and Maillard Reaction Conditions. Z. Lebensmittelunters. Forsch. A 1998, 207, 50– 54,  DOI: 10.1007/s002170050294
      [Crossref], [CAS], Google Scholar
      3
      Formation of α-dicarbonyl fragments from mono- and disaccharides under caramelization and Maillard reaction conditions
      Hollnagel, A.; Kroh, L. W.
      Zeitschrift fuer Lebensmittel-Untersuchung und -Forschung A: Food Research and Technology (1998), 207 (1), 50-54CODEN: ZLFAFA; ISSN:1431-4630. (Springer-Verlag)
      Glyoxal, methylglyoxal, and diacetyl were identified as reaction products from non-enzymic browning of D-glucose (Glc), D-fructose (Fru), maltose, and maltulose. The α-dicarbonyl compds. were quantified throughout the reaction. Monosaccharides formed more dicarbonyl fragments than disaccharides and Glc formed more than Fru. It is suggested that Fru tends to yield cyclic products rather than fragmentation products under the reaction conditions used. Furthermore, a mechanism for the fragmentation of disaccharides is proposed.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1cXkslCgsrw%253D&md5=d28458b612c96689233938dcd00fb5ce
    4. 4
      Delgado-Andrade, C.; Fogliano, V. Dietary Advanced Glycosylation End-Products (DAGEs) and Melanoidins Formed through the Maillard Reaction: Physiological Consequences of Their Intake. Annu. Rev. Food Sci. Technol. 2018, 9, 271– 291,  DOI: 10.1146/annurev-food-030117-012441
      [Crossref], [PubMed], [CAS], Google Scholar
      4
      Dietary Advanced Glycosylation End-Products (dAGEs) and Melanoidins Formed through the Maillard Reaction: Physiological Consequences of their Intake
      Delgado-Andrade, Cristina; Fogliano, Vincenzo
      Annual Review of Food Science and Technology (2018), 9 (), 271-291CODEN: ARFSBV; ISSN:1941-1413. (Annual Reviews)
      The main purpose of this review is to clarify whether the consumption of food rich in melanoidins and dietary advanced glycosylation end-products (dAGEs) is harmful or beneficial for human health. There are conflicting results on their harmful effects in the literature, partly due to a methodol. issue in how dAGEs are detd. in food. Melanoidins have pos. functions particularly within the gastrointestinal tract, whereas the intake of dAGEs has controversial physiol. consequences. Most of the in vivo intervention trials were done comparing boiled vs. roasted diet (low and high dAGE, resp.). However, these studies can be biased by different lipid oxidn. and by different calorie d. of foods in the two conditions. The attraction that humans have to cooked foods is linked to the benefits they have had during mankind's evolution. The goal for food technologists is to design low-energy-dense products that can satisfy humans' attraction to rewarding cooked foods.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhtlOguro%253D&md5=bdd63b459d68bc22272ea8a035fc0142
    5. 5
      Rabbani, N.; Thornalley, P. J. Methylglyoxal, Glyoxalase 1 and the Dicarbonyl Proteome. Amino Acids 2012, 42, 1133– 1142,  DOI: 10.1007/s00726-010-0783-0
      [Crossref], [PubMed], [CAS], Google Scholar
      5
      Methylglyoxal, glyoxalase 1 and the dicarbonyl proteome
      Rabbani, Naila; Thornalley, Paul J.
      Amino Acids (2012), 42 (4), 1133-1142CODEN: AACIE6; ISSN:0939-4451. (SpringerWienNewYork)
      A review. Methylglyoxal (MG) is a potent protein glycating agent. Glycation is directed to guanidino groups of arginine residues forming mainly hydroimidazolone Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) residues. MG-H1 formation is damaging to the proteome as modification is often directed to functionally important Arg residues. MG-H1 content of proteins is quantified by stable isotopic diln. anal. tandem mass spectrometry and also by immunoblotting with specific monoclonal antibodies. MG-glycated proteins undergo cellular proteolysis and release MG-H1 free adduct for excretion. MG-H1 residues were found in proteins of animals, plants, bacteria, fungi and protoctista. MG-H1 is often the major advanced glycation endproduct in proteins of tissues and body fluids, increasing in diabetes and assocd. vascular complications, renal failure, cirrhosis, Alzheimer's disease, arthritis, Parkinson's disease and aging. Glyoxalase 1 and aldo-keto reductase 1B1 metabolize >99% MG to innocuous products and thereby protect the proteome, providing an enzymic defense against MG-mediated glycation. Proteins susceptible to MG modification with related functional impairment are called the "dicarbonyl proteome" (DCP). DCP includes albumin, Hb, transcription factors, mitochondrial proteins, extracellular matrix proteins, lens crystallins and other proteins. DCP component proteins are linked to mitochondrial dysfunction in diabetes and aging, oxidative stress, dyslipidemia, cell detachment and anoikis and apoptosis. Biochem. and physiol. susceptibility of a protein to modification by MG and sensitivity of biochem. pathways and physiol. systems to related functional impairment under challenge of physiol. relevant increases in MG exposure are key concepts. Improved understanding of the DCP will likely have profound importance for human health, longevity and treatment of disease.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XjsVWhsrc%253D&md5=717865fe0bf51f81c51df0c21e130541
    6. 6
      Ahmad, S.; Moinuddin, M.; Shahab, U.; Habib, S.; Salman Khan, M.; Alam, K.; Ali, A. Glycoxidative Damage to Human DNA: Neo-Antigenic Epitopes on DNA Molecule Could Be a Possible Reason for Autoimmune Response in Type 1 Diabetes. Glycobiology 2014, 24, 281– 291,  DOI: 10.1093/glycob/cwt109
      [Crossref], [PubMed], [CAS], Google Scholar
      6
      Glycoxidative damage to human DNA: Neo-antigenic epitopes on DNA molecule could be a possible reason for autoimmune response in type 1 diabetes
      Ahmad, Saheem; Moinuddin; Shahab, Uzma; Habib, Safia; Salman Khan, M.; Alam, Khursheed; Ali, Asif
      Glycobiology (2014), 24 (3), 281-291CODEN: GLYCE3; ISSN:0959-6658. (Oxford University Press)
      Advanced glycation end-products (AGEs) are known to be mutagenic, diabetogenic and vascular disease risk factors. Methylglyoxal (MG) is a dicarbonyl species that reacts with biol. macromol. (proteins, DNA and lipids) to give AGEs. Nonenzymic glycation of MG with lysine (Lys) in the presence of copper (Cu2+) is reported to generate reactive oxygen species (ROS) capable of causing DNA damage. We show that DNA modification in MG-Lys-Cu2+ system results in the generation of strand breaks, base modification, hyperchromicity and increased fluorescence intensity. Superoxide generation in the MG-Lys system was found to be significantly higher when compared with that in the MG and Lys alone. Moreover, D-penicillamine and pyridoxal phosphate significantly inhibited the formation of glycation products. The presence of a major DNA glycation adduct, N2-carboxyethyl-2'-deoxyguanosine (CEdG), was detected by high performance liq. chromatog. (HPLC) and confirmed by NMR (NMR). As reported earlier, modified DNA (MG-Lys-Cu2+-DNA) was highly immunogenic in exptl. animals. Furthermore, induced anti-MG-Lys-Cu2+-DNA antibodies were effective probe for detecting glycoxidative lesions in human genomic DNA of type I diabetes patients. Our results clearly imply that interaction of MG-Lys and Cu2+ leads to the formation of AGEs and also the prodn. of potent ROS, capable of causing DNA damage, thereby playing an important role in diabetes mellitus.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFWku7w%253D&md5=50fd79691a7ee0d7fd82ed560767f52e
    7. 7
      Sato, T.; Iwaki, M.; Shimogaito, N.; Wu, X.; Yamagishi, S.-i.; Takeuchi, M. TAGE (Toxic AGEs) Theory in Diabetic Complications. Curr. Mol. Med. 2006, 6, 351– 358,  DOI: 10.2174/156652406776894536
      [Crossref], [PubMed], [CAS], Google Scholar
      7
      TAGE (toxic AGEs) theory in diabetic complications
      Sato, Takashi; Iwaki, Mina; Shimogaito, Noriko; Wu, Xuegang; Yamagishi, Sho-ichi; Takeuchi, Masayoshi
      Current Molecular Medicine (2006), 6 (3), 351-358CODEN: CMMUBP; ISSN:1566-5240. (Bentham Science Publishers Ltd.)
      A review. Diabetic complication is a leading cause of acquired blindness, end-stage renal failure, a variety of neuropathies and accelerated atherosclerosis. Chronic hyperglycemia is initially involved in the pathogenesis of diabetic micro- and macro-vascular complications via various metabolic derangements. High glucose increased prodn. of various types of advanced glycation end-products (AGEs). Recently, we found that glyceraldehyde-derived AGEs (AGE-2) play an important role in the pathogenesis of angiopathy in diabetic patients. There is considerable interest in receptor for AGEs (RAGE) found on many cell types, particularly those affected in diabetes. Recent studies suggest that interaction of AGE-2 (predominantly structure of toxic AGEs; TAGE) with RAGE alters intracellular signaling, gene expression, release of pro-inflammatory mols. and prodn. of reactive oxygen species (ROS) that contribute towards the pathol. of diabetic complications. We propose three pathways for the in vivo formation of AGE-2 precursor, glyceraldehyde, such as i) glycolytic pathway, ii) polyol pathway, and iii) fructose metabolic pathway. Glyceraldehyde can be transported or can leak passively across the plasma membrane. It can react non-enzymically with proteins to lead to accelerated formation of TAGE at both intracellularly and extracellularly. In this review, we discuss the mol. mechanisms of diabetic complications, esp. focusing on toxic AGEs (TAGE) and their receptor (RAGE) system.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XlsVGmtr4%253D&md5=40c9d078d42073205fab0927d140e140
    8. 8
      Gaens, K. H.; Stehouwer, C. D.; Schalkwijk, C. G. Advanced Glycation Endproducts and Its Receptor for Advanced Glycation Endproducts in Obesity. Curr. Opin. Lipidol. 2013, 24, 4– 11,  DOI: 10.1097/mol.0b013e32835aea13
      [Crossref], [PubMed], [CAS], Google Scholar
      8
      Advanced glycation endproducts and its receptor for advanced glycation endproducts in obesity
      Gaens, Katrien Hj.; Stehouwer, Coen Da.; Schalkwijk, Casper G.
      Current Opinion in Lipidology (2013), 24 (1), 4-11CODEN: COPLEU; ISSN:0957-9672. (Lippincott Williams & Wilkins)
      Purpose of review: To highlight the potential importance of advanced glycation endproducts (AGEs) and advanced-lipoxidn. endproducts (ALEs) in obesity and obesity-related complications, and the contribution of the receptor for advanced glycation endproducts (RAGE) and the glyoxylase defense system therein. Recent findings: Formation of AGEs/ALEs and its precursors, including methylglyoxal (MGO), are increased in conditions characterized by hyperglycemia, hyperlipidemia and enhanced oxidative stress. This metabolic profile is generally considered typical for obesity. Increased plasma and/or tissue levels of MGO and of specific AGEs/ALEs, such as N-(carboxymethyl)lysine (CML), in obesity have recently been described. In addn. to increased formation, the suppressed defense system in obesity against AGEs/ALEs formation, i.e., the glyoxylase system, will further contribute to AGEs/ALEs formation in obesity. AGEs/ALEs are not inert. In-vitro studies showed that AGEs induced the prodn. of inflammatory mediators in adipocytes and macrophages via RAGE activation, which may subsequently contribute to the development of obesity-related complications. Summary: The recognition of an enhanced AGEs/ALEs formation in adipose tissue and the biol. consequences thereof may lead to a further understanding of underlying mechanisms in dysregulated prodn. of adipokines in obesity.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXktlWmsA%253D%253D&md5=692b48aa746f329931abc8b24815f412
    9. 9
      Wellsknecht, K. J.; Zyzak, D. V.; Litchfield, J. E.; Thorpe, S. R.; Baynes, J. W. Identification of Glyoxal As the Dicarbonyl Sugar Formed on Autoxidation of Glucose - Relevance To Pathways of the Maillard Reaction in-Vivo. Diabetes 1994, 43, A96
      Google Scholar
      There is no corresponding record for this reference.
    10. 10
      Glomb, M. A.; Monnier, V. M. Mechanism of Protein Modification by Glyoxal and Glycolaldehyde, Reactive Intermediates of the Maillard Reaction. J. Biol. Chem. 1995, 270, 10017– 10026,  DOI: 10.1074/jbc.270.17.10017
      [Crossref], [PubMed], [CAS], Google Scholar
      10
      Mechanism of protein modification by glyoxal and glycolaldehyde, reactive intermediates of the Maillard reaction
      Glomb, Marcus A.; Monnier, Vincent M.
      Journal of Biological Chemistry (1995), 270 (17), 10017-26CODEN: JBCHA3; ISSN:0021-9258. (American Society for Biochemistry and Molecular Biology)
      The role of glyoxal and glycolaldehyde in protein crosslinking and Nε-(carboxymethyl)lysine (CML) formation during Maillard reaction under physiol. conditions was investigated. Incubation of bovine serum albumin with these reagents lead to rapid formation of C-2-imine cross-links and CML. Initial CML formation rate from glyoxal was not dependent on oxidn., suggesting an intramol. Cannizzaro reaction. CML formation from glucose/lysine or Amadori product of both was strongly dependent on oxidn. Blocking of Amadori product by boric acid totally suppressed CML formation from Amadori product, but only by 37% in the glucose/lysine system. Trapping of glyoxal with aminoguanidine hardly suppressed CML formation from Amadori product, whereas it blocked 50% of CML prodn. in the glucose/lysine system. While these results would support a significant role for glucose autoxidn. in CML formation, the addn. of lysine to a glucose/aminoguanidine incubation system catalyzed glyoxal-triazine formation 7-fold, thereby strongly suggesting that glucose autoxidn. is not a factor for glyoxal-mediated CML formation. Based on these results, it can be estd. that approx. 50% of the CML forming in a glucose/lysine system originates from oxidn. of Amadori product, and 40-50% originates from a pre-Amadori stage largely independent from glucose autoxidn.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2MXltlWnsrY%253D&md5=87bb958f71d4878ef88e3f476d851442
    11. 11
      Huang, Q.; Wang, P.; Zhu, Y.; Lv, L.; Sang, S. Additive Capacity of 6 -Shogaol and Epicatechin To Trap Methylglyoxal. J. Agric. Food Chem. 2017, 65, 8356– 8362,  DOI: 10.1021/acs.jafc.7b02917
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      11
      Additive Capacity of [6]-Shogaol and Epicatechin To Trap Methylglyoxal
      Huang, Qiju; Wang, Pei; Zhu, Yingdong; Lv, Lishuang; Sang, Shengmin
      Journal of Agricultural and Food Chemistry (2017), 65 (38), 8356-8362CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      Methylglyoxal (MGO), a reactive dicarbonyl species, is thought to contribute to the development of long-term pathol. diabetes as a direct toxin or as an active precursor of advanced glycation end products (AGEs). Trapping MGO by dietary phenols to inhibit the MGO induced AGE formation is an approach for alleviating diabetic complications. The present study investigated whether dietary compds. with different structures and active sites have the additive capacity to trap MGO. Ginger phenolic constituent [6]-shogaol and tea flavonoid (-)-epicatechin were selected and tested under simulated physiol. conditions, showing that they additively trapped about 41% MGO at a concn. of 10 μM within 24 h. Furthermore, whether [6]-shogaol and epicatechin can retain their MGO trapping efficacy in vivo or a biotransformation limits their MGO trapping capacity remain virtually unknown. An acute mouse study was carried out by giving a single dose of [6]-shogaol, epicatechin, and the combination of both ([6]-shogaol + epicatechin) through oral gavage. A mono-MGO adduct of [6]-shogaol was identified from [6]-shogaol and [6]-shogaol + epicatechin treated mice, and mono- and di-MGO adducts of epicatechin and its metabolite, 3'-O-Me epicatechin, were detected in urine samples collected from epicatechin and [6]-shogaol + epicatechin treated mice. To the knowledge, this is the first study demonstrating the additive MGO trapping efficacy of [6]-shogaol and epicatechin and that [6]-shogaol and epicatechin retained their MGO trapping capacity in mice.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsVagu7jP&md5=85ec2ece4042f3f316dbef152db930b1
    12. 12
      Troise, A. D.; Fiore, A.; Colantuono, A.; Kokkinidou, S.; Peterson, D. G.; Fogliano, V. Effect of Olive Mill Wastewater Phenol Compounds on Reactive Carbonyl Species and Maillard Reaction End-Products in Ultrahigh-Temperature-Treated Milk. J. Agric. Food Chem. 2014, 62, 10092– 10100,  DOI: 10.1021/jf503329d
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      12
      Effect of Olive Mill Wastewater Phenol Compounds on Reactive Carbonyl Species and Maillard Reaction End-Products in Ultrahigh-Temperature-Treated Milk
      Troise, Antonio Dario; Fiore, Alberto; Colantuono, Antonio; Kokkinidou, Smaro; Peterson, Devin G.; Fogliano, Vincenzo
      Journal of Agricultural and Food Chemistry (2014), 62 (41), 10092-10100CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      Thermal processing and Maillard reaction (MR) affect the nutritional and sensorial qualities of milk. In this paper an olive mill wastewater phenolic powder (OMW) was tested as a functional ingredient for inhibiting MR development in ultrahigh-temp. (UHT)-treated milk. OMW was added to milk at 0.1 and 0.05% w/v before UHT treatment, and the concn. of MR products was monitored to verify the effect of OMW phenols in controlling the MR. Results revealed that OMW is able to trap the reactive carbonyl species such as hydroxycarbonyls and dicarbonyls, which in turn led to the increase of Maillard-derived off-flavor development. The effect of OMW on the formation of Amadori products and N-ε-(carboxymethyl)-lysine (CML) showed that oxidative cleavage, C2-C6 cyclization, and the consequent reactive carbonyl species formation were also inhibited by OMW. Data indicated that OMW is a functional ingredient able to control the MR and to improve the nutritional and sensorial attributes of milk.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsFygtb7M&md5=3b522fb86b94e04f67c5e2311883b603
    13. 13
      Gugliucci, A.; Bastos, D. H. M.; Schulze, J.; Souza, M. F. F. Caffeic and Chlorogenic Acids in Ilex Paraguariensis Extracts Are the Main Inhibitors of AGE Generation by Methylglyoxal in Model Proteins. Fitoterapia 2009, 80, 339– 344,  DOI: 10.1016/j.fitote.2009.04.007
      [Crossref], [PubMed], [CAS], Google Scholar
      13
      Caffeic and chlorogenic acids in Ilex paraguariensis extracts are the main inhibitors of AGE generation by methylglyoxal in model proteins
      Gugliucci, A.; Bastos, Deborah H. Markowicz; Schulze, John; Souza, Marina F. Ferreira
      Fitoterapia (2009), 80 (6), 339-344CODEN: FTRPAE; ISSN:0367-326X. (Elsevier B.V.)
      The present study concs. on the evaluation of the anti-glycation effect of some bioactive substances present in yerba mate (Ilex paraguariensis): 5-caffeoylquinic acid, caffeic acid and a sapogenin (oleanolic acid). Bovine serum albumin and histones were incubated in the presence of methylglyoxal with or without the addn. of 5-caffeoylquinic acid, caffeic acid and oleanolic acid. After the incubation period, advanced glycation end product (AGE) fluorescence spectra were performed and protein structural changes were evaluated by Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis. Chlorogenic acid, caffeic acid are the main substances responsible for the anti-glycation effect of mate tea.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXoslWksro%253D&md5=2a40f5d42b904e3cf824b590d8b13c03
    14. 14
      Treibmann, S.; Spengler, F.; Degen, J.; Löbner, J.; Henle, T. Studies on the Formation of 3-Deoxyglucosone- and Methylglyoxal-Derived Hydroimidazolones of Creatine during Heat Treatment of Meat. J. Agric. Food Chem. 2019, 67, 5874– 5881,  DOI: 10.1021/acs.jafc.9b01243
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      14
      Studies on the Formation of 3-Deoxyglucosone- and Methylglyoxal-Derived Hydroimidazolones of Creatine during Heat Treatment of Meat
      Treibmann, Stephanie; Spengler, Franz; Degen, Julia; Loebner, Juergen; Henle, Thomas
      Journal of Agricultural and Food Chemistry (2019), 67 (20), 5874-5881CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      Dicarbonyl compds. such as methylglyoxal (MGO) and 3-deoxyglucosone (3-DG) are formed via caramelization and the Maillard reaction in food during heating or in vivo as byproducts of glycolysis. Recently, it was shown that creatine, an amino compd. linked to the energy metab. in vertebrate muscle, reacts rapidly with methylglyoxal under physiol. conditions to form N-(4-methyl-5-oxo-1-imidazolin-2-yl)sarcosine (MG-HCr), a methylglyoxal-derived hydroimidazolone of creatine. Based on the observation that heated meat contains only small amts. of MGO and 3-DG when compared to many other foodstuffs, the aim of this study was to investigate a possible reaction of creatine with 3-DG and MGO in meat. From incubation mixts. consisting of 3-DG and creatine, a new hydroimidazolone of creatine, namely N-(4-butyl-1,2,3-triol-5-oxo-1-imidazolin-2-yl)sarcosine (3-DG-HCr), was isolated and characterized via spectroscopic means. To quantitate 3-DG-HCr and MG-HCr, meat and fish products were analyzed via HPLC-MS/MS using isotopically labeled std. material. Whereas samples of raw fish and meat contained only trace amts. of the hydroimidazolones (below 5 μg/kg), up to 28.3 mg/kg MG-HCr and up to 15.3 mg/kg 3-DG-HCr were found in meat and fish products. The concns. were dependent on the heat treatment and presumably on the smoking process. In comparison to the lysine and arginine derivs. CEL, pyrraline, and MG-H1, the derivatization rate of creatine as MG-HCr and 3-DG-HCr was higher than of lysine and arginine, which clearly demonstrates the 1,2-dicarbonyl scavenging properties of creatine in meat.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXoslSlsrc%253D&md5=d3eacbc65f86542c4458a333000b1327
    15. 15
      Löbner, J.; Degen, J.; Henle, T. Creatine Is a Scavenger for Methylglyoxal under Physiological Conditions via Formation of N -(4-Methyl-5-Oxo-1-Imidazolin-2-Yl)Sarcosine (MG-HCr). J. Agric. Food Chem. 2015, 63, 2249– 2256,  DOI: 10.1021/jf505998z
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      15
      Creatine is a scavenger for methylglyoxal under physiological conditions via formation of N-(4-methyl-5-oxo-1-imidazolin-2-yl)sarcosine (MG-HCr)
      Lobner Jurgen; Degen Julia; Henle Thomas
      Journal of agricultural and food chemistry (2015), 63 (8), 2249-56 ISSN:.
      Following incubation of methylglyoxal and creatine under physiological conditions, N-(4-methyl-5-oxo-1-imidazolin-2-yl)sarcosine (MG-HCr) was isolated and identified by NMR and mass spectrometry. Due to its rapid formation, MG-HCr represents a specific product following "scavenging" of methylglyoxal by creatine. Using hydrophilic interaction chromatography coupled to mass spectrometry, MG-HCr was analyzed in urine samples of healthy volunteers. Daily MG-HCr excretion of nonvegetarians ranged from 0.35 to 3.84 μmol/24 h urine (median: 0.90 μmol/24 h urine) and of vegetarians from 0.11 to 0.31 μmol/24 h urine (median: 0.19 μmol/24 h urine), indicating that formation of MG-HCr in vivo is influenced by the dietary intake of creatine. The trapping of methylglyoxal by creatine may delay the formation of advanced glycation compounds in vivo and, therefore, could be of special importance in situations in which the body has to deal with pathophysiologically increased amounts of dicarbonyl compounds ("carbonyl stress"), for instance in diabetic patients.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC2MrjtVCrtg%253D%253D&md5=05e9b53c0367acac620c6ee705c54dc8
    16. 16
      Rabbani, N.; Xue, M.; Thornalley, P. J. Dicarbonyls and Glyoxalase in Disease Mechanisms and Clinical Therapeutics. Glycoconjugate J. 2016, 33, 513– 525,  DOI: 10.1007/s10719-016-9705-z
      [Crossref], [PubMed], [CAS], Google Scholar
      16
      Dicarbonyls and glyoxalase in disease mechanisms and clinical therapeutics
      Rabbani, Naila; Xue, Mingzhan; Thornalley, Paul J.
      Glycoconjugate Journal (2016), 33 (4), 513-525CODEN: GLJOEW; ISSN:0282-0080. (Springer)
      The reactive dicarbonyl metabolite methylglyoxal (MG) is the precursor of the major quant. advanced glycation endproducts (AGEs) in physiol. systems - arginine-derived hydroimidazolones and deoxyguanosine-derived imidazopurinones. The glyoxalase system in the cytoplasm of cells provides the primary defense against dicarbonyl glycation by catalyzing the metab. of MG and related reactive dicarbonyls. Dicarbonyl stress is the abnormal accumulation of dicarbonyl metabolites leading to increased protein and DNA modification contributing to cell and tissue dysfunction in ageing and disease. It is produced endogenously by increased formation and/or decreased metab. of dicarbonyl metabolites. Dicarbonyl stress contributes to ageing, disease and activity of cytotoxic chemotherapeutic agents. It contributes to ageing through age-related decline in glyoxalase 1 (Glo-1) activity. Glo-1 has a dual role in cancer as a tumor suppressor protein prior to tumor development and mediator of multi-drug resistance in cancer treatment, implicating dicarbonyl glycation of DNA in carcinogenesis and dicarbonyl-driven cytotoxicity in mechanism of action of anticancer drugs. Glo-1 is a driver of cardiovascular disease, likely through dicarbonyl stress-driven dyslipidemia and vascular cell dysfunction. Dicarbonyl stress is also a contributing mediator of obesity and vascular complications of diabetes. There are also emerging roles in neurol. disorders. Glo-1 responds to dicarbonyl stress to enhance cytoprotection at the transcriptional level through stress-responsive increase of Glo-1 expression. Small mol. Glo-1 inducers are in clin. development for improved metabolic, vascular and renal health and Glo-1 inhibitors in preclin. development for multidrug resistant cancer chemotherapy.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhtFGlsbjF&md5=b397a992b016d4b78d39f6081437d196
    17. 17
      Baynes, J. W.; Thorpe, S. R. Glycoxidation and Lipoxidation in Atherogenesis. Free Radical Biol. Med. 2000, 28, 1708– 1716,  DOI: 10.1016/s0891-5849(00)00228-8
      [Crossref], [PubMed], [CAS], Google Scholar
      17
      Glycoxidation and lipoxidation in atherogenesis
      Baynes, J. W.; Thorpe, S. R.
      Free Radical Biology & Medicine (2000), 28 (12), 1708-1716CODEN: FRBMEH; ISSN:0891-5849. (Elsevier Science Inc.)
      A review with 73 refs. Atherosclerosis may be viewed as an age-related disease initiated by nonenzymic, chem. reactions in a biol. system. The peroxidn. of lipids in lipoproteins in the vascular wall leads to local prodn. of reactive carbonyl species that mediate recruitment of macrophages, cellular activation and proliferation, and chem. modification of vascular proteins by advanced lipoxidn. end-products (ALEs). The ALEs and their precursors affect the structure and function of the vascular wall, setting the stage for atherogenesis. The increased risk for atherosclerosis in diabetes may result from addnl. carbonyl prodn. from carbohydrates and addnl. chem. modification of proteins by advanced glycation end-products (AGEs). Failure to maintain homeostasis and the increase in oxidizable substrate (lipid) alone, rather than oxidative stress, is the likely source of the increase in reactive carbonyl precursors and the resultant ALEs and AGEs in atherosclerosis. Nucleophilic AGE-inhibitors, such as aminoguanidine and pyridoxamine, which trap reactive carbonyls and inhibit the formation of AGEs in diabetes, also trap bioactive lipids and precursors of ALEs in atherosclerosis. These drugs should be effective in retarding the development of atherosclerosis, even in nondiabetic patients.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3cXls1Giu7k%253D&md5=8ab4fef4917dd773e9c794f2f97a0ef8
    18. 18
      Davies, M. J. Protein Oxidation and Peroxidation. Biochem. J. 2016, 473, 805– 825,  DOI: 10.1042/bj20151227
      [Crossref], [PubMed], [CAS], Google Scholar
      18
      Protein oxidation and peroxidation
      Davies, Michael J.
      Biochemical Journal (2016), 473 (7), 805-825CODEN: BIJOAK; ISSN:0264-6021. (Portland Press Ltd.)
      Proteins are major targets for radicals and two-electron oxidants in biol. systems due to their abundance and high rate consts. for reaction. With highly reactive radicals damage occurs at multiple side-chain and backbone sites. Less reactive species show greater selectivity with regard to the residues targeted and their spatial location. Modification can result in increased side-chain hydrophilicity, side-chain and backbone fragmentation, aggregation via covalent crosslinking or hydrophobic interactions, protein unfolding and altered conformation, altered interactions with biol. partners and modified turnover. In the presence of O2, high yields of peroxyl radicals and peroxides (protein peroxidn.) are formed; the latter account for up to 70% of the initial oxidant flux. Protein peroxides can oxidize both proteins and other targets. One-electron redn. results in addnl. radicals and chain reactions with alcs. and carbonyls as major products; the latter are commonly used markers of protein damage. Direct oxidn. of cysteine (and less commonly) methionine residues is a major reaction; this is typically faster than with H2O2, and results in altered protein activity and function. Unlike H2O2, which is rapidly removed by protective enzymes, protein peroxides are only slowly removed, and catabolism is a major fate. Although turnover of modified proteins by proteasomal and lysosomal enzymes, and other proteases (e.g. mitochondrial Lon), can be efficient, protein hydroperoxides inhibit these pathways and this may contribute to the accumulation of modified proteins in cells. Available evidence supports an assocn. between protein oxidn. and multiple human pathologies, but whether this link is causal remains to be established.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XkvFClsLg%253D&md5=fd1192a5ac27edeb8583228d439afca9
    19. 19
      Van den Eynde, M. D. G.; Geleijnse, J. M.; Scheijen, J. L. J. M.; Hanssen, N. M. J.; Dower, J. I.; Afman, L. A.; Stehouwer, C. D. A.; Hollman, P. C. H.; Schalkwijk, C. G. Quercetin, but Not Epicatechin, Decreases Plasma Concentrations of Methylglyoxal in Adults in a Randomized, Double-Blind, Placebo-Controlled, Crossover Trial with Pure Flavonoids. J. Nutr. 2018, 148, 1911– 1916,  DOI: 10.1093/jn/nxy236
      [Crossref], [PubMed], [CAS], Google Scholar
      19
      Quercetin, but Not Epicatechin, Decreases Plasma Concentrations of Methylglyoxal in Adults in a Randomized, Double-Blind, Placebo-Controlled, Crossover Trial with Pure Flavonoids
      Van den Eynde Mathias D G; Scheijen Jean L J M; Hanssen Nordin M J; Stehouwer Coen D A; Schalkwijk Casper G; Van den Eynde Mathias D G; Scheijen Jean L J M; Hanssen Nordin M J; Stehouwer Coen D A; Schalkwijk Casper G; Geleijnse Johanna M; Dower James I; Afman Lydia A; Hollman Peter C H
      The Journal of nutrition (2018), 148 (12), 1911-1916 ISSN:.
      Background: Methylglyoxal (MGO) is the most potent precursor of advanced glycation end products (AGEs). MGO and AGEs have been associated with diabetes, its complications, and other age-related diseases. Experimental studies have shown that the flavonoids quercetin and epicatechin are able to scavenge MGO and lower AGE formation. Objective: Data on the effects of these flavonoids on MGO and AGE concentrations in humans are not yet available. We therefore investigated the effect of quercetin and epicatechin on the concentrations of MGO and AGEs in a post hoc analysis. Methods: Thirty-seven apparently healthy, nonsmoking adults with a systolic blood pressure between 125 and 160 mm Hg at screening were included in a randomized, double-blind, placebo-controlled crossover trial. Participants ingested (-)-epicatechin (100 mg/d), quercetin 3-glucoside (160 mg/d), or placebo capsules for periods of 4 wk separated by 4-wk washout periods. Fasting blood samples were collected at the start and end of each intervention period. Liquid chromatography-tandem mass spectrometry was used to determine plasma concentrations of the dicarbonyl compounds MGO, glyoxal (GO), and 3-deoxyglucosone (3-DG) and free and protein-bound AGEs. Gene expression of glyoxalase 1 (GLO1), the enzyme involved in the degradation of MGO, was determined by either microarray or quantitative reverse transcriptase-polymerase chain reaction. Results: The treatment effect (Δtreatment - Δplacebo) of quercetin on MGO was -40.2 nmol/L (95% CI: -73.6, -6.8 nmol/L; P = 0.019), a decrease of 11% from baseline values, whereas GO, 3-DG, and free and protein-bound AGEs did not change significantly. Epicatechin did not affect the concentrations of dicarbonyls and free and protein-bound AGEs. We did not find a significant change in expression of GLO1. Conclusions: In apparently healthy (pre)hypertensive men and women, quercetin but not epicatechin decreased plasma MGO concentrations. Quercetin may potentially form a new treatment strategy for diseases in which MGO plays a pivotal role. This study was registered at clinicaltrials.gov as NCT01691404.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BB3cvntVGlsw%253D%253D&md5=177bef325087ca769c3df5710f4f6700
    20. 20
      Palma-Duran, S. A.; Lean, M. E. J.; Combet, E. Roasted Instant Coffees: Analysis of (Poly) Phenols and Melanoidins Antioxidant Capacity, Potassium and Sodium Contents. Proc. Nutr. Soc. 2016, 75, E63  DOI: 10.1017/s0029665116000537
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    21. 21
      Rufián-Henares, J. A.; Morales, F. J. A New Application of a Commercial Microtiter Plate-Based Assay for Assessing the Antimicrobial Activity of Maillard Reaction Products. Food Res. Int. 2006, 39, 33– 39,  DOI: 10.1016/j.foodres.2005.06.002
      [Crossref], [CAS], Google Scholar
      21
      A new application of a commercial microtiter plate-based assay for assessing the antimicrobial activity of Maillard reaction products
      Rufian-Henares, Jose A.; Morales, Francisco J.
      Food Research International (2005), 39 (1), 33-39CODEN: FORIEU; ISSN:0963-9969. (Elsevier B.V.)
      A new application of a com. microtiter plate-based assay was developed for the quant. screening of antimicrobial compds. formed during the thermal treatment of foods. Such compds. called Maillard reaction products (MRP) are widely distributed in the diet of western countries. The reported method is fast, cheap and easy and facilitates the generation of a dose-response curve which allows calcg. the antimicrobial activity of most substances at the same time as min. inhibitory concn. (MIC) or as oxytetracyclin equiv. value (OTEV). The test is accurate and highly reproducible (inter- and intra-day variation of 2.3% and 1.8%, resp.). For the tested samples, the higher antimicrobial activity was found in coffee melanoidins (high mol. wt. fraction of MRP) although non-covalently melanoidins-linked compds. showed antimicrobial activity too. In addn., melanoidins from more severely treated samples exerted higher inhibitory bacterial growing activity, such as CTn60 coffee (highest roasting degree) and dark beer.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXhtFWhtrvO&md5=c1c1488d4a649ba22f0c65f374b2b33d
    22. 22
      Morales, F. J.; Somoza, V.; Fogliano, V. Physiological Relevance of Dietary Melanoidins. Amino Acids 2012, 42, 1097– 1109,  DOI: 10.1007/s00726-010-0774-1
      [Crossref], [PubMed], [CAS], Google Scholar
      22
      Physiological relevance of dietary melanoidins
      Morales, Francisco J.; Somoza, Veronika; Fogliano, Vincenzo
      Amino Acids (2012), 42 (4), 1097-1109CODEN: AACIE6; ISSN:0939-4451. (SpringerWienNewYork)
      A review. Melanoidins are the final products of the Maillard reaction. The main dietary sources of melanoidins are coffee, bread crust, bakery products, black beer and cocoa. Although the chem. structures of melanoidins are widely unknown, data from gravimetric techniques allow to roughly est. a daily intake in the order of 10 g with a Western diet. Melanoidins contribute to the sensorial properties, modulating texture and flavor of foods. Growing evidence also suggests that melanoidins have health beneficial properties, such as chemopreventive, antioxidant and antimicrobial activities, and the ability to chelate different minerals. In the gastrointestinal tract, melanoidins behave not only as antioxidants, but also as dietary fiber by promoting the growth of bifidobacteria. This array of biol. activities suggests the need for anal. techniques to identify the melanoidin structures and to control their formation during thermal food processing.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XjsVWhsrw%253D&md5=4608f3bdd551881aa804e65bc42f8a4d
    23. 23
      Borrelli, R. C.; Esposito, F.; Napolitano, A.; Ritieni, A.; Fogliano, V. Characterization of a New Potential Functional Ingredient: Coffee Silverskin. J. Agric. Food Chem. 2004, 52, 1338– 1343,  DOI: 10.1021/jf034974x
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      23
      Characterization of a New Potential Functional Ingredient: Coffee Silverskin
      Borrelli, Rosa Cinzia; Esposito, Fabrizio; Napolitano, Aurora; Ritieni, Alberto; Fogliano, Vincenzo
      Journal of Agricultural and Food Chemistry (2004), 52 (5), 1338-1343CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      Dietary fiber (DF) is one of the main dietary factors contributing to consumers' well-being. In this work the possibility of using the roasted coffee silverskin (CS), a byproduct of roasted coffee beans, as a DF-rich ingredient has been evaluated. The results showed that this material has 60% total DF, with a relevant component (14%) of sol. DF. Although a small amt. of free phenol compds. is present in CS, it has a marked antioxidative activity, which can be attributed to the huge amt. of Maillard reaction products, the melanoidins. Static batch culture fermn. expts. showed that CS induces preferential growth of bifidobacteria rather than clostridia and Bacteroides spp. CS can be proposed as a new potential functional ingredient in consideration of the high content of sol. DF, the marked antioxidant activity, and the potential prebiotic activity.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXps1emsQ%253D%253D&md5=41fee00afd193a4d477582d7f0fd7c76
    24. 24
      Summa, C.; McCourt, J.; Cämmerer, B.; Fiala, A.; Probst, M.; Kun, S.; Anklam, E.; Wagner, K.-H. Radical Scavenging Activity, Anti-Bacterial and Mutagenic Effects of Cocoa Bean Maillard Reaction Products with Degree of Roasting. Mol. Nutr. Food Res. 2008, 52, 342– 351,  DOI: 10.1002/mnfr.200700403
      [Crossref], [PubMed], [CAS], Google Scholar
      24
      Radical scavenging activity, anti-bacterial and mutagenic effects of Cocoa bean Maillard Reaction products with degree of roasting
      Summa, Carmelina; McCourt, Josephine; Cammerer, Bettina; Fiala, Annette; Probst, Martina; Kun, Szillard; Anklam, Elke; Wagner, Karl-Heinz
      Molecular Nutrition & Food Research (2008), 52 (3), 342-351CODEN: MNFRCV; ISSN:1613-4125. (Wiley-VCH Verlag GmbH & Co. KGaA)
      Raw, pre-roasted and roasted Cocoa samples were sepd. into 4 different mol. wt. fractions (> 30, 30-10, 10-5 and < 5 kDa) with ultrafiltration and tested for their antibacterial, mutagenic, as well as their radical-scavenging effects. Radical-scavenging effects were tested with electro paramagnetic resonance spectroscopy, anti-mutagenicity in the Salmonella microsome assay (with and without metabolic activation), and antibacterial effects by incubating the fractions with several strains of Bifidobacteria, Enterobacter and Escherichia, and observing their growth. The radical-scavenging activity and reducing substance concns. increased, particularly in the 5-10-kDa roasted fraction. Chromaticity testing elucidated that the 10-5-kDa fraction was one of the darkest fractions. The Salmonella microsome assay showed neither mutagenic nor anti-mutagenic effects in any of the samples at any of the different concns. applied when using TA98, TA100 and TA102. All fractions reduced the growth of pathogenic bacteria, in particular at the highest concn. of 100 μg/mL; however, the same trends were also obsd. for Bifidobacteria.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXktVemu70%253D&md5=3b35098f3249ced3bdf663f3c227f6c5
    25. 25
      Fogliano, V.; Morales, F. J. Estimation of Dietary Intake of Melanoidins from Coffee and Bread. Food Funct. 2011, 2, 117– 123,  DOI: 10.1039/c0fo00156b
      [Crossref], [PubMed], [CAS], Google Scholar
      25
      Estimation of dietary intake of melanoidins from coffee and bread
      Fogliano, Vincenzo; Morales, Francisco J.
      Food & Function (2011), 2 (2), 117-123CODEN: FFOUAI; ISSN:2042-6496. (Royal Society of Chemistry)
      Melanoidins are defined as polymeric high mol. wt., brown-colored Maillard reaction end-products, contg. nitrogen. They escape digestion and pass through the upper gastrointestinal tract and can interact with the different microbial species present in the colon. Major dietary sources of melanoidins are coffee and bread crust. Both coffee and bread crust melanoidins can be fermented by the human hindgut microflora thus sharing some of the properties attributed to dietary fiber. Despite the emerging pos. physiol. properties of such dietary constituents their intake has not been estd. yet. To this aim melanoidin content in different type of coffee brews, bread and dry biscuits was detd. by sequential ultrafiltration and enzymic digestion. Despite some drawbacks and limiting steps in the calcn., such as the lack of a ref. material, an educated guess on the dietary intake of melanoidins has been put forward. Data indicated that the intake of coffee melanoidins ranged between 0.5 to 2.0 g per day for moderate and heavy consumers, resp. For bread and dry biscuits an intake in the ranges of 1.8-15.0 and 3.2-8.5 g per day has been calcd. These figures suggest that a realistic estn. of melanoidins dietary intake for general population would be close to 10 g per day considering all the possible alimentary sources.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhs1yltr0%253D&md5=39cd9f122ab2840e7d15a059aecf4c7a
    26. 26
      Nunes, F. M.; Coimbra, M. A. Chemical Characterization of the High Molecular Weight Material Extracted with Hot Water from Green and Roasted Arabica Coffee. J. Agric. Food Chem. 2001, 49, 1773– 1782,  DOI: 10.1021/jf0012953
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      26
      Chemical Characterization of the High Molecular Weight Material Extracted with Hot Water from Green and Roasted Arabica Coffee
      Nunes, Fernando M.; Coimbra, Manuel A.
      Journal of Agricultural and Food Chemistry (2001), 49 (4), 1773-1782CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      The polysaccharides present in coffee infusions are known to contribute to the organoleptic characteristics of the drink, such as the creamy sensation perceived in the mouth known as "body", the release of aroma substances, and the stability of espresso coffee foam. To increase the knowledge about the origin, compn., and structure of the polysaccharide fraction, the high mol. wt. material (HMWM) was extd. with hot water from 2 green and roasted ground arabica coffees: Costa Rica (wet processed) and Brazil (dry processed). The polysaccharides present in the green coffees HMWM were arabinogalactans (62%), galactomannans (24%), and glucans, and those found in roasted coffees were galactomannans (69%) and arabinogalactans (28%). The polysaccharides of the HMWM of the roasted coffees were less branched than those of the green coffees. The major green coffee proteins had mol. wts. of 58 and 38 kDa, and the 58 kDa protein had two subunits, of 38 and 20 kDa, possibly linked by disulfide bonds. The protein fraction obtained from roasted coffees had only a defined band with ≤14 kDa and a diffuse band with >200 kDa. The majority of the galactomannans were pptd. with solns. of 50% ethanol, and the size-exclusion chromatog. of the roasted fractions showed Co-elution of polysaccharides, proteins, phenolics, and brown compds. The use of strong hydrogen and hydrophobic dissocn. conditions allowed us to conclude that the phenolics and brown compds. were linked by covalent bonds to the polymeric material.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXhsFKhur8%253D&md5=541c8b6305d1404560c915b2090d709b
    27. 27
      Summa, C.; Raposo, F. C.; McCourt, J.; Scalzo, R. L.; Wagner, K.-H.; Elmadfa, I.; Anklam, E. Effect of Roasting on the Radical Scavenging Activity of Cocoa Beans. Eur. Food Res. Technol. 2006, 222, 368– 375,  DOI: 10.1007/s00217-005-0005-2
      [Crossref], [CAS], Google Scholar
      27
      Effect of roasting on the radical scavenging activity of cocoa beans
      Summa, Carmelina; Raposo, Fernando Cordeiro; McCourt, Josephine; Lo Scalzo, Roberto; Wagner, Karl-Heinz; Elmadfa, Ibrahim; Anklam, Elke
      European Food Research and Technology (2006), 222 (3-4), 368-375CODEN: EFRTFO; ISSN:1438-2377. (Springer GmbH)
      The free-radical scavenging activity of cocoa samples subjected to different roasting treatments was detd. The samples (raw, pre-roasted and roasted) were sepd. into 4 mol. wt. fractions per sample (>30, 30-10, 10-5, and <5 kDa). The free-radical scavenging activity was detd. with the DPPH• (1,1-dipheny-2-picrylhydrazyl), and ABTS•+ [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] free-radical scavenging assays for all samples. Both tests were compared in terms of sensitivity and measurement precision, at different reaction times. Comparing the results from each test, the free-radical scavenging activity trends were similar for each fraction but with notable differences in the sensitivity of the assays. Anal. of the concn. of reducing substances, such as water sol. phenolics, melanoidins, carbohydrates, etc, in these fractions by the photometric Folin-Ciocalteu assay, showed a similar pattern to the free-radical scavenging activity trend. Moreover, this comparison showed that there were significantly (P < 0.05) more reducing substances and free-radical scavenging activity in the 10-5 kDa roasted cocoa bean fraction.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28Xht1Cnu7o%253D&md5=d6c232f1d39a0a9ef5c0bf717ff90d2d
    28. 28
      Borrelli, R. C.; Mennella, C.; Barba, F.; Russo, M.; Russo, G. L.; Krome, K.; Erbersdobler, H. F.; Faist, V.; Fogliano, V. Characterization of Coloured Compounds Obtained by Enzymatic Extraction of Bakery Products. Food Chem. Toxicol. 2003, 41, 1367– 1374,  DOI: 10.1016/s0278-6915(03)00140-6
      [Crossref], [PubMed], [CAS], Google Scholar
      28
      Characterization of coloured compounds obtained by enzymatic extraction of bakery products
      Borrelli, R. C.; Mennella, C.; Barba, F.; Russo, M.; Russo, G. L.; Krome, K.; Erbersdobler, H. F.; Faist, V.; Fogliano, V.
      Food and Chemical Toxicology (2003), 41 (10), 1367-1374CODEN: FCTOD7; ISSN:0278-6915. (Elsevier Science B.V.)
      Melanoidins, the brown-colored polymers formed through Maillard type reaction in several heat-treated foods, represent a significant part of our diet, with an av. intake of grams per day. Most of the studies on the physiol. effects of these compds. have been performed using the water sol. melanoidin fractions. But dietary melanoidins formed on the surface of bakery products are poorly sol. in water as well as in org. solvents. An enzymic solubilization procedure was developed on a gluten-glucose model system and it was applied to bread and biscuits. The sol. material obtained was tested for its antioxidant activity, for its effect on phase-I and phase-II xenobiotic enzymes and for potential cytotoxic effects. Sol. melanoidins from model system and biscuits exhibit a strong antioxidant activity and do not show any cytotoxicity on Caco-2 cells. Melanoidins extd. from biscuits was able to inhibit the activity of Phase I (NADPH-cytochrome-c reductase) and Phase II (Glutathione-S-transferase) enzymes, whereas the low mol. wt. melanoidins isolated from gluten-glucose model system inhibit the activity of NADPH-cytochrome-c reductase.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXlvFGhsL0%253D&md5=efc9f599aae89afaba9a2bfc67475bcc
    29. 29
      Glomb, M. A.; Tschirnich, R. Detection of α-Dicarbonyl Compounds in Maillard Reaction Systems and in Vivo. J. Agric. Food Chem. 2001, 49, 5543– 5550,  DOI: 10.1021/jf010148h
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      29
      Detection of α-Dicarbonyl Compounds in Maillard Reaction Systems and in Vivo
      Glomb, Marcus A.; Tschirnich, Roswitha
      Journal of Agricultural and Food Chemistry (2001), 49 (11), 5543-5550CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      α-Dicarbonyl compds. are of major interest in food chem. and biochem. as important precursors of, for example, protein modifications and flavor. Due to their high reactivity most of the published structures were identified and quantitated as stable derivs. after reaction with trapping reagents. However, the present study showed for the 1st time that the trapping reagents are of dramatic impact on the final qual. and quant. α-dicarbonyl spectrum. As important representatives, aminoguanidine and o-phenylenediamine were used to compare trapping characteristics and to monitor the dicarbonyl structures arising from the degrdn. of an Amadori compd. Dicarbonyl structures with a reductone moiety could not be or were only insufficiently detected by slow-reacting reagents such as aminoguanidine. On the other hand, fast-reacting chems. such as o-phenylenediamine imposed high oxidative stress on the investigated system and led to enhanced or false pos. formation of dicarbonyl compds. generated by oxidative pathways.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXnvVOltrs%253D&md5=55122455d9fb9d35594acbd8bf060060
    30. 30
      Hellwig, M.; Gensberger-Reigl, S.; Henle, T.; Pischetsrieder, M. Food-Derived 1,2-Dicarbonyl Compounds and Their Role in Diseases. Seminars in Cancer Biology; Elsevier, 2018; Vol. 49, pp 1– 8.
      [Crossref], Google Scholar
      There is no corresponding record for this reference.
    31. 31
      Delgado-Andrade, C.; Morales, F. J. Unraveling the Contribution of Melanoidins to the Antioxidant Activity of Coffee Brews. J. Agric. Food Chem. 2005, 53, 1403– 1407,  DOI: 10.1021/jf048500p
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      31
      Unraveling the contribution of melanoidins to the antioxidant activity of coffee brews
      Delgado-Andrade, Cristina; Morales, Francisco J.
      Journal of Agricultural and Food Chemistry (2005), 53 (5), 1403-1407CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      Instant coffees produced from the same green coffee beans were supplied from a company in different roasting degrees, light, medium, and dark. Melanoidins were obtained by ultrafiltration (10 kDa) and subsequent diafiltration. Pure melanoidins were isolated from melanoidins after overnight incubation in 2 M NaCl. The antioxidant activities of instant coffees, melanoidins, and pure melanoidins were tested using the conjugated diene formation from a 2,2'-azobis(2-amidinopropane) dihydrochloride-induced linoleic acid oxidn. in an aq. system. No significant differences were found between melanoidins and pure melanoidins with different roasting degrees. Therefore, the contribution of the pure melanoidin fraction to the total antioxidant activity of melanoidins was significantly lower. More than 50% of the antioxidant activity of melanoidins is due to low mol. wt. compds. linked non-covalently to the melanoidin skeleton. A new concept of the overall antioxidant properties of food melanoidins is described, where chelating ability toward low mol. wt. antioxidant compds. is connected to the stabilization of these compds. involved in the shelf life of the product.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXhtFegsbY%253D&md5=71b9723d18d86e229381bf7be2f91144
    32. 32
      Oracz, J.; Nebesny, E.; Żyżelewicz, D. Identification and Quantification of Free and Bound Phenolic Compounds Contained in the High-Molecular Weight Melanoidin Fractions Derived from Two Different Types of Cocoa Beans by UHPLC-DAD-ESI-HR-MSn. Food Res. Int. 2019, 115, 135– 149,  DOI: 10.1016/j.foodres.2018.08.028
      [Crossref], [PubMed], [CAS], Google Scholar
      32
      Identification and quantification of free and bound phenolic compounds contained in the high-molecular weight melanoidin fractions derived from two different types of cocoa beans by UHPLC-DAD-ESI-HR-MSn
      Oracz, Joanna; Nebesny, Ewa; Zyzelewicz, Dorota
      Food Research International (2019), 115 (), 135-149CODEN: FORIEU; ISSN:0963-9969. (Elsevier B.V.)
      The aim of the present study was to establish the profiles of sol. free phenolics (SFPs) and bound phenolics (BPs) in high mol. wt. (HMW) melanoidin fractions isolated from raw and roasted beans of two Theobroma cacao L. varieties. Samples were prepd. using three methods (saline treatment and acidic and alk. hydrolysis) to obtain different forms of phenolic compds. A total of fifteen phenolics, including three flavan-3-ols, seven phenolic acids, one phenolic aldehyde, and four N-phenylpropenoyl-L-amino acids (NPAs), were identified using ultra-high-performance liq. chromatog. coupled to diode array detection and electrospray ionization high-resoln. mass spectrometry (UHPLC-DAD-ESI-HR-MSn). In HMW fractions from both studied cocoa types, the main SFPs were N-caffeoyl-L-Asp and procyanidin B2, whereas the main BPs were catechin, epicatechin, ellagic acid, protocatechualdehyde, and N-caffeoyl-L-Asp. The concns. of individual BPs were much higher than the content of total SFPs. It was also found that, as compared to alk. hydrolysis, acid hydrolysis released a significantly higher amt. of BPs from HMW melanoidin fractions. A comprehensive quant. anal. indicated significant variation in the investigated phenolic compds. depending on the cocoa type and roasting conditions. An increase in treatment temp. from 110 to 150 °C led to a decline in SFPs and an increment in BPs. The HMW fractions of unroasted Criollo beans exhibited the highest content of SFPs and the lowest content of BPs. The highest BP concns. were obtained for both cocoa bean varieties roasted at 150 °C. The present study revealed that HMW melanoidin fractions from cocoa beans of different varieties roasted at higher temps. are a good source of phenolic compds. that can be released under both acidic and alk. conditions.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhsFCjtr7F&md5=80997c7cfa41efb888ea9d1d18d78e29
    33. 33
      Coelho, C.; Ribeiro, M.; Cruz, A. C. S.; Domingues, M. R. M.; Coimbra, M. A.; Bunzel, M.; Nunes, F. M. Nature of Phenolic Compounds in Coffee Melanoidins. J. Agric. Food Chem. 2014, 62, 7843– 7853,  DOI: 10.1021/jf501510d
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      33
      Nature of Phenolic Compounds in Coffee Melanoidins
      Coelho, Carina; Ribeiro, Miguel; Cruz, Ana C. S.; Domingues, M. Rosario M.; Coimbra, Manuel A.; Bunzel, Mirko; Nunes, Fernando M.
      Journal of Agricultural and Food Chemistry (2014), 62 (31), 7843-7853CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      Phenolic compds. are incorporated into coffee melanoidins during roasting mainly in condensed form (42-62 mmol/100 g) and also in ester-linked form (1.1-1.6 mmol/100 g), with incorporation levels depending on the green coffee chlorogenic acid content. The phenolic compds. are incorporated in different coffee melanoidin populations, but mainly in those sol. in 75% ethanol (82%), a significant correlation between the amt. of phenolic compds. and the amt. of protein and color characteristics of the different melanoidin populations being obsd. The incorporation of phenolic compds. into coffee melanoidins is a significant pathway of chlorogenic acid degrdn. during roasting, representing 23% of the chlorogenic acids lost. These account for the nearly 26% of the material not accounted for by polysaccharides and proteins present in coffee melanodins. The cleavage mechanism and the efficiency of alk. fusion used to release condensed phenolics from coffee melanoidins suggest that the phenolic compds. can be linked to the polymeric material by aryl-ether, stilbene type, and/or biphenyl linkages.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFShs7fP&md5=2395e80cf0ff96142064ad4e40d4d4ed
    34. 34
      Fernandez-Gomez, B.; Ullate, M.; Picariello, G.; Ferranti, P.; Mesa, M. D.; del Castillo, M. D. New Knowledge on the Antiglycoxidative Mechanism of Chlorogenic Acid. Food Funct. 2015, 6, 2081– 2090,  DOI: 10.1039/c5fo00194c
      [Crossref], [PubMed], [CAS], Google Scholar
      34
      New knowledge on the antiglycoxidative mechanism of chlorogenic acid
      Fernandez-Gomez, Beatriz; Ullate, Monica; Picariello, Gianluca; Ferranti, Pasquale; Mesa, Maria Dolores; del Castillo, Maria Dolores
      Food & Function (2015), 6 (6), 2081-2090CODEN: FFOUAI; ISSN:2042-6496. (Royal Society of Chemistry)
      The role of chlorogenic acid (CGA) in the formation of advanced glycation end-products (AGEs) (glycoxidn. reaction) was studied. Model systems composed of bovine serum albumin (BSA) (1 mg mL-1) and methylglyoxal (5 mM) under mimicked physiol. conditions (pH 7.4, 37 °C) were used to evaluate the antiglycoxidative effect of CGA (10 mM). The stability of CGA under reaction conditions was assayed by HPLC and MALDI-TOF MS. The glycoxidn. reaction was estd. by anal. of free amino groups by the OPA assay, spectral anal. of fluorescent AGEs and total AGEs by ELISA, and color formation by absorbance at 420 nm. Structural changes in protein were evaluated by anal. of phenol bound to the protein backbone using the Folin reaction, UV-Vis spectral anal. and MALDI-TOF-MS, while changes in protein function were measured by detg. the antioxidant capacity using the ABTS radical cation decolorisation assay. CGA was isomerized and oxidized under our exptl. conditions. Evidence of binding between BSA and multiple CGA and/or its deriv. mols. (isomers and oxidn. products) was found. CGA inhibited (p < 0.05) the formation of fluorescent and total AGEs at 72 h of reaction by 91.2 and 69.7%, resp. The binding of phenols to BSA significantly increased (p < 0.001) its antioxidant capacity. Correlations between free amino group content, phenol bound to protein and antioxidant capacity were found. Results indicate that CGA simultaneously inhibits the formation of potentially harmful compds. (AGEs) and promotes the generation of neoantioxidant structures.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXotlKjtbk%253D&md5=9874dedc1f770b2603386361d40b6f97
    35. 35
      Meade, S. J.; Miller, A. G.; Gerrard, J. A. The Role of Dicarbonyl Compounds in Non-Enzymatic Crosslinking: A Structure-Activity Study. Bioorg. Med. Chem. 2003, 11, 853– 862,  DOI: 10.1016/s0968-0896(02)00564-3
      [Crossref], [PubMed], [CAS], Google Scholar
      35
      The role of dicarbonyl compounds in non-enzymatic crosslinking: a structure-activity study
      Meade, Susie J.; Miller, Antonia G.; Gerrard, Juliet A.
      Bioorganic & Medicinal Chemistry (2003), 11 (6), 853-862CODEN: BMECEP; ISSN:0968-0896. (Elsevier Science Ltd.)
      The Maillard reaction is a complex network of reactions that has been shown to result in the non-enzymic crosslinking of proteins. Recent attention has focussed on the role of α-dicarbonyl compds. as important in vivo contributors to protein crosslinking but, despite extensive research, the mol. mechanisms of the crosslinking reaction remain open to conjecture. In particular, no relationship between the structure of the carbonyl-contg. compds. and their activity as crosslinking agents has been established. In an effort to elucidate a structure-reactivity relationship, a wide range of dicarbonyl compds., including linear, cyclic, di-aldehyde and di-ketone compds., were reacted with the model protein RNase A and their crosslinking activity assessed. Methylglyoxal and glutaraldehyde were found to be the most efficient crosslinkers, while closely related mols. effected crosslinking at a much lower rate. Cyclopentan-1,2-dione was also shown to be a reactive crosslinking agent. The efficiency of methylglyoxal and glutaraldehyde at crosslinking is thought to be related to their ability to form stable heterocyclic compds. that are the basis of protein crosslinks. The reasons for the striking reactivity of these two compds., compared to closely related structures is explained by subtle balances between competing pathways in a complex reaction network.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXhsVCitL8%253D&md5=46f3ae8dc852bbf2ef46fd50abdfc842
    36. 36
      Voziyan, P. A.; Metz, T. O.; Baynes, J. W.; Hudson, B. G. A Post-Amadori Inhibitor Pyridoxamine Also Inhibits Chemical Modification of Proteins by Scavenging Carbonyl Intermediates of Carbohydrate and Lipid Degradation. J. Biol. Chem. 2002, 277, 3397– 3403,  DOI: 10.1074/jbc.m109935200
      [Crossref], [PubMed], [CAS], Google Scholar
      36
      A post-Amadori inhibitor pyridoxamine also inhibits chemical modification of proteins by scavenging carbonyl intermediates of carbohydrate and lipid degradation
      Voziyan, Paul A.; Metz, Thomas O.; Baynes, John W.; Hudson, Billy G.
      Journal of Biological Chemistry (2002), 277 (5), 3397-3403CODEN: JBCHA3; ISSN:0021-9258. (American Society for Biochemistry and Molecular Biology)
      Reactive carbonyl compds. are formed during autoxidn. of carbohydrates and peroxidn. of lipids. These compds. are intermediates in the formation of advanced glycation end products (AGE) and advanced lipoxidn. end products (ALE) in tissue proteins during aging and in chronic disease. We studied the reaction of carbonyl compds. glyoxal (GO) and glycolaldehyde (GLA) with pyridoxamine (PM), a potent post-Amadori inhibitor of AGE formation in vitro and of development of renal and retinal pathol. in diabetic animals. PM reacted rapidly with GO and GLA in neutral, aq. buffer, forming a Schiff base intermediate that cyclized to a hemiaminal adduct by intramol. reaction with the phenolic hydroxyl group of PM. This bicyclic intermediate dimerized to form a five-ring compd. with a central piperazine ring, which was characterized by electrospray ionization-liq. chromatog./mass spectrometry, NMR, and x-ray crystallog. PM also inhibited the modification of lysine residues and loss of enzymic activity of RNase in the presence of GO and GLA and inhibited formation of the AGE/ALE Nε-(carboxymethyl)lysine during reaction of GO and GLA with bovine serum albumin. Our data suggest that the AGE/ALE inhibitory activity and the therapeutic effects of PM obsd. in diabetic animal models depend, at least in part, on its ability to trap reactive carbonyl intermediates in AGE/ALE formation, thereby inhibiting the chem. modification of tissue proteins.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XhtVaktrw%253D&md5=311b3afcfb1e69474b1b24841f2afa3d
    37. 37
      Rogalla, P.; Lembcke, A.; Rückert, J. C.; Hein, E.; Bollow, M.; Rogalla, N. E.; Hamm, B. Spasmolysis at CT Colonography: Butyl Scopolamine versus Glucagon. Radiology 2005, 236, 184– 188,  DOI: 10.1148/radiol.2353040007
      [Crossref], [PubMed], [CAS], Google Scholar
      37
      Spasmolysis at CT colonography: butyl scopolamine versus glucagon
      Rogalla Patrik; Lembcke Alexander; Ruckert Jens C; Hein Eike; Bollow Matthias; Rogalla Noga E; Hamm Bernd
      Radiology (2005), 236 (1), 184-8 ISSN:0033-8419.
      PURPOSE: To retrospectively determine if the use of butyl scopolamine or glucagon in the supine patient improves colonic distention and reduces the number of collapsed intestinal segments at computed tomographic (CT) colonography. MATERIALS AND METHODS: This study had institutional review board approval; subject informed consent was not required. CT colonography was performed without the administration of an intravenous spasmolytic in 80 asymptomatic subjects (group 1; 45 women, 35 men; age range, 48-77 years; mean, 61.9 years). These subjects were matched with two groups of 80 subjects who were similar in age but were premedicated with glucagon (group 2; 41 women, 39 men; age range, 43-76 years; mean, 63.1 years) or butyl scopolamine (group 3; 43 women, 37 men; age range, 34-77 years; mean, 63.4 years). All 240 subjects were examined in the supine position with multisection CT and a section thickness of 1 mm after intravenous contrast agent administration and rectal carbon dioxide insufflation. The colon was divided into seven segments, and the colon length, total volume, radial distensibility, and number of non-distended segments were calculated for each subject and compared among the three groups. Statistical analysis was performed with analysis of variance and chi2 testing. RESULTS: Mean bowel length was not significantly different among the groups. Mean colon volumes and radial distensibilities, respectively, were 1.84 L and 3.69 cm in group 1, 2.14 L and 3.98 cm in group 2, and 2.35 L and 4.23 cm in group 3; differences in colon volume and radial distensibility were significant only between group 1 and group 3 (P < .001). At CT colonography, 29 segments in 20 group 1 subjects were collapsed, 23 segments in 12 group 2 subjects were collapsed, and 11 segments in six group 3 subjects were collapsed (P = .016). CONCLUSION: Premedication with butyl scopolamine or, less effectively, glucagon improves colonic distention in the supine subject.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BD2MzjslGjsA%253D%253D&md5=758a7119bdf0144e76668ba5d3be8745
    38. 38
      Vitaglione, P.; Fogliano, V.; Pellegrini, N. Coffee, Colon Function and Colorectal Cancer. Food Funct. 2012, 3, 916– 922,  DOI: 10.1039/c2fo30037k
      [Crossref], [PubMed], [CAS], Google Scholar
      38
      Coffee, colon function and colorectal cancer
      Vitaglione, Paola; Fogliano, Vincenzo; Pellegrini, Nicoletta
      Food & Function (2012), 3 (9), 916-922CODEN: FFOUAI; ISSN:2042-6496. (Royal Society of Chemistry)
      A review. For several years the physiol. effects of coffee have been focused on its caffeine content, disregarding the hundreds of bioactive coffee components, such as polyphenols, melanoidins, carbohydrates, diterpenes, etc. These compds. may exert their protection against colorectal cancer (CRC), the third most common cancer worldwide. However, the amt. and type of compds. ingested with the beverage may be highly different depending on the variety of coffee used, the roasting degree, the type of brewing method as well as the serving size. In this frame, this paper reviews the mechanisms by which coffee may influence the risk of CRC development focusing on espresso and filtered coffee, as well as on the components that totally or partially reach the colon i.e. polyphenols and dietary fiber, including melanoidins. In particular the effects of coffee on some colon conditions whose deregulation may lead to cancer, namely microbiota compn. and lumen reducing environment, were considered. Taken together the discussed studies indicated that, due to their in vivo metab. and compn., both coffee chlorogenic acids and dietary fiber, including melanoidins, may reduce CRC risk, increasing colon motility and antioxidant status. Further studies should finally assess whether the coffee benefits for colon are driven through a prebiotic effect.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xht1GjurjL&md5=521f154d06ef6ff1fe7060bf0513a4a2
    39. 39
      Mesías, M.; Navarro, M.; Martínez-Saez, N.; Ullate, M.; del Castillo, M. D.; Morales, F. J. Antiglycative and Carbonyl Trapping Properties of the Water Soluble Fraction of Coffee Silverskin. Food Res. Int. 2014, 62, 1120– 1126,  DOI: 10.1016/j.foodres.2014.05.058
      [Crossref], [CAS], Google Scholar
      39
      Antiglycative and carbonyl trapping properties of the water soluble fraction of coffee silverskin
      Mesias, M.; Navarro, M.; Martinez-Saez, N.; Ullate, M.; del Castillo, M. D.; Morales, F. J.
      Food Research International (2014), 62 (), 1120-1126CODEN: FORIEU; ISSN:0963-9969. (Elsevier B.V.)
      Carbonyl stress and accumulation of advanced glycation end-products (AGEs) in human tissues are involved in diabetic complications, atherosclerosis, Alzheimer's disease and aging. The objective of this study was to evaluate the in vitro protective effect of aq. exts. of coffee silverskin (CS) in the formation of AGEs and trapping of carbonyl reactive species such as methylglyoxal (MGO). Aq. exts. of CS from Arabica and Robusta coffee varieties were obtained under environment friendly extn. conditions. CS exts. were characterized by the anal. of dietary fiber, caffeine, chlorogenic acids (CGAs), total phenolic compds., browning, melanoidins, and antioxidant capacity. CS exts. and CGA exhibited a dose-dependent anti-AGE capacity in the protein-glucose model system (37 °C/21 days) with an IC50 of 0.6 mg/mL and 0.4 mg/mL, resp. Caffeine did not prevent AGE formation under the studied conditions. Regardless to protein-MGO assay (37 °C/14 days), the anti-AGE capacity of CS exts. and CGA was also dose-dependent with an IC50 of 1.3 mg/mL and 0.1 mg/mL, resp. Caffeine weakly inhibited the reaction of protein and MGO. The MGO trapping capacity was established as a model for protection against carbonyl stress. Robusta CS was very effective for the direct trapping of MGO with an IC50 of 0.055 mg/mL as compared with Arabica CS (IC50 of 0.6 mg/mL). CGA and caffeine showed an IC50 for MGO trapping capacity of 0.14 mg/mL and > 10 mg/mL, resp. The highest CGA content in the Robusta CS ext. could explain its higher MGO trapping activity as compared with the Arabica CS ext. The anti-AGE and MGO trapping capacities of CS may be assocd. to other chem. components besides CGA. In conclusion, aq. CS ext. may be considered as a natural source of inhibitors of in vitro formation of AGEs and carbonyl stress. The inhibitory effect of the coffee exts. may be assocd. to their carbonyl trapping capacity.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFSqsbjF&md5=14b280e48f840cdfc842bb4b832b2261
    40. 40
      Yoon, S.-R.; Shim, S.-M. Inhibitory Effect of Polyphenols in Houttuynia Cordata on Advanced Glycation End-Products (AGEs) by Trapping Methylglyoxal. LWT-Food Sci. Technol. 2015, 61, 158– 163,  DOI: 10.1016/j.lwt.2014.11.014
      [Crossref], [CAS], Google Scholar
      40
      Inhibitory effect of polyphenols in Houttuynia cordata on advanced glycation end-products (AGEs) by trapping methylglyoxal
      Yoon, So-Ra; Shim, Soon-Mi
      LWT--Food Science and Technology (2015), 61 (1), 158-163CODEN: LSTWB3; ISSN:0023-6438. (Elsevier Ltd.)
      The inhibitory effect of bioactive components from Houttuynia cordata (H. cordata) on advanced glycation end-products (AGEs) by trapping methylglyoxal (MGO) was investigated. MGO and its adducts of quercitrin, chlorogenic acid, rutin was analyzed by using liq. chromatog.-mass spectrometry (LC-MS/MSn). The remaining MGO were 52.3, 26.7, and 9.4% for chlorogenic acid, quercitrin, and rutin, resp. and the mono- or di-MGO conjugated adducts of quercitrin and rutin were identified at 24 h of reaction. The formation of AGEs was detected through the reaction of glucose with protein by the fluorescence method. During the glycation reaction, quercitrin, rutin, and methanol ext. of H. cordata decreased the prodn. level of AGEs by 91-94.6 %. H. cordata contg. chlorogenic acid, quercitrin, and rutin may have potential role in minimizing AGEs formation.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvFGisrnP&md5=da001678ca5431ba31156f1bf65988c2
    41. 41
      Moreira, A. S. P.; Nunes, F. M.; Domingues, M. R.; Coimbra, M. A. Coffee Melanoidins: Structures, Mechanisms of Formation and Potential Health Impacts. Food Funct. 2012, 3, 903– 915,  DOI: 10.1039/c2fo30048f
      [Crossref], [PubMed], [CAS], Google Scholar
      41
      Coffee melanoidins: structures, mechanisms of formation and potential health impacts
      Moreira, Ana S. P.; Nunes, Fernando M.; Domingues, M. Rosario; Coimbra, Manuel A.
      Food & Function (2012), 3 (9), 903-915CODEN: FFOUAI; ISSN:2042-6496. (Royal Society of Chemistry)
      A review. During the roasting process, coffee bean components undergo structural changes leading to the formation of melanoidins, which are defined as high mol. wt. nitrogenous and brown-colored compds. As coffee brew is one of the main sources of melanoidins in the human diet, their health implications are of great interest. In fact, several biol. activities, such as antioxidant, antimicrobial, anticariogenic, anti-inflammatory, antihypertensive, and antiglycative activities, have been attributed to coffee melanoidins. To understand the potential of coffee melanoidin health benefits, it is essential to know their chem. structures. The studies undertaken to date dealing with the structural characterization of coffee melanoidins have shown that polysaccharides, proteins, and chlorogenic acids are involved in coffee melanoidin formation. However, exact structures of coffee melanoidins and mechanisms involved in their formation are far from being elucidated. This paper systematizes the available information and provides a crit. overview of the knowledge obtained so far about the structure of coffee melanoidins, mechanisms of their formation, and their potential health implications.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xht1GjurjM&md5=c0d1aaa5d8d68e29fb305c81a264085d
    42. 42
      Xie, C.; Yu, K.; Zhong, D.; Yuan, T.; Ye, F.; Jarrell, J. A.; Millar, A.; Chen, X. Investigation of Isomeric Transformations of Chlorogenic Acid in Buffers and Biological Matrixes by Ultraperformance Liquid Chromatography Coupled with Hybrid Quadrupole/Ion Mobility/Orthogonal Acceleration Time-of-Flight Mass Spectrometry. J. Agric. Food Chem. 2011, 59, 11078– 11087,  DOI: 10.1021/jf203104k
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      42
      Investigation of Isomeric Transformations of Chlorogenic Acid in Buffers and Biological Matrixes by Ultraperformance Liquid Chromatography Coupled with Hybrid Quadrupole/Ion Mobility/Orthogonal Acceleration Time-of-Flight Mass Spectrometry
      Xie, Cen; Yu, Kate; Zhong, Dafang; Yuan, Tao; Ye, Fei; Jarrell, Joseph Andy; Millar, Alan; Chen, Xiaoyan
      Journal of Agricultural and Food Chemistry (2011), 59 (20), 11078-11087CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      Ultraperformance liq. chromatog. coupled with hybrid quadrupole/ion mobility/orthogonal acceleration time-of-flight (oa-TOF) mass spectrometry (UPLC-IM-MS) was used to study the isomeric transformations of trans-5-caffeoylquinic acid, an extremely active compd. present in multiple vegetables, fruits, and beverages. The UPLC/oa-TOF MS results proved that in phosphate buffer (pH 7.4), plasma, or urine sample, trans-5-caffeoylquinic acid first isomerizes to trans-4-caffeoylquinic acid and then to trans-3-caffeoylquinic acid by intramol. acyl migration. When exposed to UV light, trans-3-, -4-, and -5-caffeoylquinic acids undergo cis/trans isomerization to form cis isomers. The isomerization was solely dependent on the pH of the matrix, as well as the incubation temp., and was independent of metabolic enzymes. UPLC-IM-MS results revealed that a reversible cis/trans isomerization of caffeoylquinic acids could also be induced by the elec. field in an electrospray source. Thus, understanding the possible role of elec. field-induced isomerization of caffeoylquinic acids may help lessen the confusion between gas phase phenomena and liq. state chem. when applying IM-MS anal. The comprehensive understanding of caffeoylquinic acid isomerization transformations is crucial for the appropriate handling of samples and interpretation of exptl. data.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXht1GgtbzF&md5=17a4d4f709c8ddc10e67bb7238495fb0
    43. 43
      Moreira, A. S. P.; Nunes, F. M.; Simões, C.; Maciel, E.; Domingues, P.; Domingues, M. R. M.; Coimbra, M. A. Transglycosylation Reactions, a Main Mechanism of Phenolics Incorporation in Coffee Melanoidins: Inhibition by Maillard Reaction. Food Chem. 2017, 227, 422– 431,  DOI: 10.1016/j.foodchem.2017.01.107
      [Crossref], [PubMed], [CAS], Google Scholar
      43
      Transglycosylation reactions, a main mechanism of phenolics incorporation in coffee melanoidins: Inhibition by Maillard reaction
      Moreira, Ana S. P.; Nunes, Fernando M.; Simoes, Cristiana; Maciel, Elisabete; Domingues, Pedro; Domingues, M. Rosario M.; Coimbra, Manuel A.
      Food Chemistry (2017), 227 (), 422-431CODEN: FOCHDJ; ISSN:0308-8146. (Elsevier Ltd.)
      Under roasting conditions, polysaccharides depolymerize and also are able to polymerize, forming new polymers through non-enzymic transglycosylation reactions (TGRs). TGRs can also occur between carbohydrates and aglycons, such as the phenolic compds. present in daily consumed foods like coffee. In this study, glycosidically-linked phenolic compds. were quantified in coffee melanoidins, the polymeric nitrogenous brown-colored compds. formed during roasting, defined as end-products of Maillard reaction. One third of the phenolics present were in glycosidically-linked form. In addn., the roasting of solid-state mixts. mimicking coffee beans compn. allowed the conclusion that proteins play a regulatory role in TGRs extension and, consequently, modulate melanoidins compn. Overall, the results obtained showed that TGRs are a main mechanism of phenolics incorporation in melanoidins and are inhibited by amino groups through Maillard reaction.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXitVylurs%253D&md5=094a554b5d059120023be51a40fecccd
    44. 44
      Nunes, F. M.; Coimbra, M. A. Melanoidins from Coffee Infusions. Fractionation, Chemical Characterization, and Effect of the Degree of Roast. J. Agric. Food Chem. 2007, 55, 3967– 3977,  DOI: 10.1021/jf063735h
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      44
      Melanoidins from Coffee Infusions. Fractionation, Chemical Characterization, and Effect of the Degree of Roast
      Nunes, Fernando M.; Coimbra, Manuel A.
      Journal of Agricultural and Food Chemistry (2007), 55 (10), 3967-3977CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      A method involving fractionation in ethanol aq. solns., anion exchange chromatog., and immobilized copper chelating chromatog. was developed to obtain high mol. wt. anionic melanoidin populations from coffee infusions. Six anionic fractions with different physicochem. properties (ethanol soly. and chelating ability) and chem. compn. regarding carbohydrate as well as protein nature and content were isolated. Fractions with similar chem. compn. were obtained for light-, medium-, and dark-roasted coffee infusions. These melanoidin fractions accounted for 30-33% of the cold-water sol. high mol. wt. material, independently of the degree of roast in coffee. The nature and abundance of the different polysaccharides in each fraction were dependent on their ethanol soly. The 50% ethanol insol. melanoidin populations contained mostly galactomannan-like carbohydrates, and the fractions obtained with 75% ethanol contained mostly arabinogalactan-like carbohydrates. The melanoidin populations with chelating properties presented significantly lower carbohydrate content and, from these, the 75% ethanol sol. fractions were almost devoid of carbohydrate material. The results obtained suggest that the chelating ability of these coffee melanoidins is modulated by their carbohydrates.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXksFSnsL0%253D&md5=4eeeb1807dcfa24ab5763967dfe9f311
    45. 45
      Monente, C.; Ludwig, I. A.; Irigoyen, A.; De Peña, M.-P.; Cid, C. Assessment of Total (Free and Bound) Phenolic Compounds in Spent Coffee Extracts. J. Agric. Food Chem. 2015, 63, 4327– 4334,  DOI: 10.1021/acs.jafc.5b01619
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      45
      Assessment of Total (Free and Bound) Phenolic Compounds in Spent Coffee Extracts
      Monente, Carmen; Ludwig, Iziar A.; Irigoyen, Angel; De Pena, Maria-Paz; Cid, Concepcion
      Journal of Agricultural and Food Chemistry (2015), 63 (17), 4327-4334CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      Spent coffee is the main byproduct of the brewing process and a potential source of bioactive compds., mainly phenolic acids easily extd. with water. Free and bound caffeoylquinic (3-CQA, 4-CQA, 5-CQA), dicaffeoylquinic (3,4-diCQA, 3,5-diCQA, 4,5-diCQA), caffeic, ferulic, p-coumaric, sinapic, and 4-hydroxybenzoic acids were measured by HPLC, after the application of three treatments (alk., acid, saline) to spent coffee exts. Around 2-fold higher content of total phenolics has been estd. in comparison to free compds. Phenolic compds. with one or more caffeic acid mols. were approx. 54% linked to macromols. such as melanoidins, mainly by noncovalent interactions (up to 81% of bound phenolic compds.). The rest of the quantitated phenolic acids were mainly attached to other structures by covalent bonds (62-97% of total bound compds.). Alk. hydrolysis and saline treatment were suitable to est. total bound and ionically bound phenolic acids, resp., whereas acid hydrolysis is an inadequate method to quantitate coffee phenolic acids.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXms1OgsLc%253D&md5=ec5ceebfd00716ea903a700ad7b3da07
    46. 46
      Vitaglione, P.; Napolitano, A.; Fogliano, V. Cereal Dietary Fibre: A Natural Functional Ingredient to Deliver Phenolic Compounds into the Gut. Trends Food Sci. Technol. 2008, 19, 451– 463,  DOI: 10.1016/j.tifs.2008.02.005
      [Crossref], [CAS], Google Scholar
      46
      Cereal dietary fibre: a natural functional ingredient to deliver phenolic compounds into the gut
      Vitaglione, Paola; Napolitano, Aurora; Fogliano, Vincenzo
      Trends in Food Science & Technology (2008), 19 (9), 451-463CODEN: TFTEEH; ISSN:0924-2244. (Elsevier Ltd.)
      A review. Epidemiol. studies assoc. whole grain consumption with a reduced risk of many diseases. This paper focuses on the antioxidant component of cereal dietary fiber starting from its chem. structure, bioavailability and biol. meaning. By the crit. assessment of the intervention studies performed using cereal bran and whole grains, the hypothesis that the slow and continuous release in the gut of the dietary fiber bound antioxidants dets. the health benefits, is illustrated. In the last part of the work, new perspectives and technol. possibilities to enhance the health potential of this cereal component are also highlighted.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXptVWqsrw%253D&md5=0dda35cf84b89b8a54c860f39228275b
    47. 47
      Saura-Calixto, F. Antioxidant Dietary Fiber Product: A New Concept and a Potential Food Ingredient. J. Agric. Food Chem. 1998, 46, 4303– 4306,  DOI: 10.1021/jf9803841
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      47
      Antioxidant Dietary Fiber Product: A New Concept and a Potential Food Ingredient
      Saura-Calixto, Fulgencio
      Journal of Agricultural and Food Chemistry (1998), 46 (10), 4303-4306CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      The main characteristics of a natural product, antioxidant dietary fiber (ADF), rich in both dietary fiber (DF) and polyphenolic compds. (PP), obtained from red grape pomace is described. Both nonextractable proanthocyanidins (28.6%) and extractable polyphenols (2.0%) are assocd. with the dietary fiber matrix. The antioxidant capacity of this product was detd. in vitro by lipid oxidn. inhibition (LOI) and free radical scavenging (FRE) procedures. One gram of the product showed similar LOI and FRE effects as 400 mg and 100 mg of DL-α-tocopherol, resp. Extractable PP of grape ADF showed higher antioxidant capacity than red wine PP. The physiol. and nutritional significance of ADF is discussed and the requirements of vegetable materials to be considered as ADF is proposed.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1cXmtV2gtbk%253D&md5=653a71cf769037571a87ad781b257104
    48. 48
      López-Galilea, I.; Andueza, S.; Leonardo, I. d.; Paz de Peña, M.; Cid, C. Influence of Torrefacto Roast on Antioxidant and Pro-Oxidant Activity of Coffee. Food Chem. 2006, 94, 75– 80,  DOI: 10.1016/j.foodchem.2004.10.052
      [Crossref], [CAS], Google Scholar
      48
      Influence of torrefacto roast on antioxidant and pro-oxidant activity of coffee
      Lopez-Galilea, Isabel; Andueza, Susana; di Leonardo, Isabella; Paz de Pena, M.; Cid, Concepcion
      Food Chemistry (2005), 94 (1), 75-80CODEN: FOCHDJ; ISSN:0308-8146. (Elsevier B.V.)
      The addn. of sugar at the end of the torrefacto roasting process may influence the antioxidant and pro-oxidant properties of coffee because sugar is one of the main precursors the Maillard reaction. The aim of the work was to study and to compare the antioxidant and pro-oxidant properties of some com. roasted coffees which are selected to represent conventional roasted arabica coffee and arabica/robusta blends, and torrefacto roasted blends. Higher antioxidant activity was obsd. in Colombian coffees than in conventional roasted coffee blends. On the other hand, when the percentage of torrefacto coffee was increased, an increase of the antioxidant activity and a slight tendency to decrease the pro-oxidant activity were obsd. Moreover, principal component anal. allowed sepn. of: (a) brands by PC1 (46.9%), characterized by color parameters defined by roasting degree and (b) torrefacto roasted blends by PC2 (33.7%), characterized by antioxidant/pro-oxidant activity.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXlvV2rsbs%253D&md5=654748126cf95329b720305e35cb4881
    49. 49
      Rufián-Henares, J. A.; Morales, F. J. Effect of in Vitro Enzymatic Digestion on Antioxidant Activity of Coffee Melanoidins and Fractions. J. Agric. Food Chem. 2007, 55, 10016– 10021,  DOI: 10.1021/jf0718291
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      49
      Effect of in vitro enzymatic digestion on antioxidant activity of coffee melanoidins and fractions
      Rufian-Henares, Jose A.; Morales, Francisco J.
      Journal of Agricultural and Food Chemistry (2007), 55 (24), 10016-10021CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      Traditionally antioxidant activity of melanoidins has only been evaluated in food for implication in shelf life but gastrointestinal digestion is necessary to study their potential bioactivity. In addn., the biol. fate of melanoidins has been stressed during the past decade since they did not behave as inert substances. In the present paper a sol. coffee melanoidin isolated from brewed coffee after ultrafiltration with a 10 kDa cutoff membrane was treated ionically and enzymically collecting the resp. high and low mol. wt. fractions. Antioxidant activity of these fractions was evaluated with five well-described assays (DPPH, ABTS, ORAC, HOSC, and FRAP) that were previously setup in a plate reader based automatized anal. Low mol. wt. compds. released from melanoidin after gastrointestinal digestion exerted the highest antioxidant activity, even higher than compds. bound ionically to melanoidins. Gastrointestinal digestion is able to modify coffee melanoidins to some extent, as hypothesized from their abs. antioxidant activities. Two options are plausible: by modifying/releasing the ionically bound compds. and/or by genesis of new more active structures from the melanoidin skeleton after enzymic treatment.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXht1alsbfE&md5=703af6a2c2a09477b4facbd3053d1396
    50. 50
      Borrelli, R. C.; Visconti, A.; Mennella, C.; Anese, M.; Fogliano, V. Chemical Characterization and Antioxidant Properties of Coffee Melanoidins. J. Agric. Food Chem. 2002, 50, 6527– 6533,  DOI: 10.1021/jf025686o
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      50
      Chemical Characterization and Antioxidant Properties of Coffee Melanoidins
      Borrelli, Rosa Cinzia; Visconti, Attilio; Mennella, Carmela; Anese, Monica; Fogliano, Vincenzo
      Journal of Agricultural and Food Chemistry (2002), 50 (22), 6527-6533CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      Melanoidins, the brown polymers formed through Maillard reaction during coffee roasting, constitute up to 25% of the coffee beverages' dry matter. In this study chem. characterization of melanoidins obtained from light-, medium-, and dark-roasted coffee beans, manufd. from the same starting material, was performed. Melanoidins were sepd. by gel filtration chromatog. and studied by MALDI-TOF mass spectrometry. Results showed that the amt. of melanoidins present in the brews increased as the intensity of the thermal treatment increased, while their mol. wt. decreased. The antioxidant activity of melanoidins isolated from the different brews was studied by using different methodologies. Melanoidins antiradical activity detd. by ABTS•+ and DMPD•+ assays decreased as the intensity of roasting increased, but the ability to prevent linoleic acid peroxidn. was higher in the dark-roasted samples. Data suggest that melanoidins must be carefully considered when the relevance of coffee intake in human health is studied.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XntFegs7Y%253D&md5=3ee4c0dbe7fbb89e61fb6e5a5a1cb33b
    51. 51
      Dittrich, R.; Dragonas, C.; Kannenkeril, D.; Hoffmann, I.; Mueller, A.; Beckmann, M. W.; Pischetsrieder, M. A Diet Rich in Maillard Reaction Products Protects LDL against Copper Induced Oxidation Ex Vivo, a Human Intervention Trial. Food Res. Int. 2009, 42, 1315– 1322,  DOI: 10.1016/j.foodres.2009.04.007
      [Crossref], [CAS], Google Scholar
      51
      A diet rich in Maillard reaction products protects LDL against copper induced oxidation ex vivo, a human intervention trial
      Dittrich, R.; Dragonas, C.; Kannenkeril, D.; Hoffmann, I.; Mueller, A.; Beckmann, M. W.; Pischetsrieder, M.
      Food Research International (2009), 42 (9), 1315-1322CODEN: FORIEU; ISSN:0963-9969. (Elsevier B.V.)
      Maillard reaction products (MRPs) have antioxidative properties in vitro but the influence of a diet rich in MRPs on oxidative damage in vivo remains unknown. In this study, the influence of thermally processed foods rich in MRPs on copper induced oxidn. of human low-d. lipoprotein (LDL) in vitro was examd. Moreover, oxidative resistance of LDL (OR) in blood plasma of eight healthy subjects was monitored, who consumed diets poor and rich in MRPs in weekly turn for 3 wk. Dark beer, bread crust, and roasted coffee led to a statistically significant increased OR in vitro compared to pale beer, bread crumb, and raw coffee. The consumption of a diet rich in MRPS significantly increased plasma OR compared to the diet poor in MRPs by 35.5%. This study indicates that thermally processed foods rich in MRPs inhibit the LDL oxidn. in vitro and have the ability to reduce oxidative modification of LDL in vivo.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtVSisbnF&md5=680902b7e4445b05aa993a9b9bcf1f56
    52. 52
      Wu, Z.-J.; Ma, X.-L.; Fang, D.-M.; Qi, H.-Y.; Ren, W.-J.; Zhang, G.-L. Analysis of Caffeic Acid Derivatives from Osmanthus Yunnanensis Using Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry. Eur. J. Mass Spectrom. 2009, 15, 415– 429,  DOI: 10.1255/ejms.992
      [Crossref], [PubMed], [CAS], Google Scholar
      52
      Analysis of caffeic acid derivatives from Osmanthus yunnanensis using electrospray ionization quadrupole time-of-flight mass spectrometry
      Wu, Zhi-Jun; Ma, Xiao-Li; Fang, Dong-Mei; Qi, Hua-Yi; Ren, Wei-Jian; Zhang, Guo-Lin
      European Journal of Mass Spectrometry (2009), 15 (3), 415-429CODEN: EJMSCL; ISSN:1469-0667. (IM Publications)
      A series of six caffeic acid derivs. (1-6) in Osmanthus yunnanensis were investigated by electrospray quadrupole time-of-flight tandem mass spectrometry (ESI-QToF-MS/MS) in both neg.- and pos.-ion modes. High-quality MS/MS spectra of [M + H]+ are generated from high-abundance protonated parent ions obtained by addn. of ammonium chloride to the solns. Fragmentation mechanisms of [M - H]- and [M + H]+ precursor ions were proposed and elemental compns. of most of the product ions were confirmed on the basis of the high-resoln. ESI-collision-induced dissocn. (CID)-MS/MS spectra. It was found that the fragment ions at m/z 179, m/z 161, m/z 135 and m/z 134 in neg.-ion mode and at m/z 163, m/z 145 and m/z 135 in pos. mode should be the characteristic ions of caffeic acid. In addn., the radical fragment ions with high abundance were obsd. for many caffeic acid derivs. esp. for 4. The structural elements of unknown compds. 7 and 8 were tentatively identified on based on tandem mass spectra of known ones.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXmtV2gs7Y%253D&md5=5bb61c2aa010deeba2ea3452e03acc0b
    53. 53
      Totlani, V. M.; Peterson, D. G. Epicatechin Carbonyl-Trapping Reactions in Aqueous Maillard Systems: Identification and Structural Elucidation. J. Agric. Food Chem. 2006, 54, 7311– 7318,  DOI: 10.1021/jf061244r
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      53
      Epicatechin Carbonyl-Trapping Reactions in Aqueous Maillard Systems: Identification and Structural Elucidation
      Totlani, Vandana M.; Peterson, Devin G.
      Journal of Agricultural and Food Chemistry (2006), 54 (19), 7311-7318CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      Recently, the group reported via labeling expts. that epicatechin in Maillard reaction aq. glucose-glycine model systems formed adduct reaction products with C2, C3, and C4 sugar fragments. In the current study, the identity of the sugar fragment precursors responsible for adduct generation by directly comparing the liq. chromatog.-mass spectrometry properties of these reported epicatechin (EC)-sugar fragments adducts with those generated from reactions consisting of only EC and well-known Maillard-generated glucose fragments (i.e., glyoxal, glycolaldehyde, methylglyoxal, glyceraldehyde, etc.) was investigated. The structural properties of an EC-methylglyoxal adduct reaction product were also analyzed by NMR. The most likely precursors for the C2, C3, and C4 sugar moiety of the EC-sugar fragment adducts were identified as glyoxal, hydroxyacetone, and erythrose, resp. 1H NMR anal. of the EC-methylglyoxal indicated that the analyte underwent rapid conformational/constitutional exchange. Using cold temp. (-25 °C) two-dimensional NMR analyses (heteronuclear multiple bond coherence, heteronuclear multiple quantum coherence, and 1H-1H correlation spectroscopy), the structure of one of the isomers was reported to consist of a covalent linkage between the C1 position of the methylglyoxal and either the C6 or the C8 position of the EC A ring, presumably generated by hydroxyalkylation and arom. substitution reactions.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28Xoslaksb4%253D&md5=a94bd8c133d30be87c67fdea155c230a
    54. 54
      Lo, C.-Y.; Hsiao, W.-T.; Chen, X.-Y. Efficiency of Trapping Methylglyoxal by Phenols and Phenolic Acids. J. Food Sci. 2011, 76, H90– H96,  DOI: 10.1111/j.1750-3841.2011.02067.x
      [Crossref], [PubMed], [CAS], Google Scholar
      54
      Efficiency of trapping methylglyoxal by phenols and phenolic acids
      Lo, Chih-Yu; Hsiao, Wen-Tuan; Chen, Xiu-Yu
      Journal of Food Science (2011), 76 (3), H90-H96CODEN: JFDSAZ; ISSN:0022-1147. (Wiley-Blackwell)
      The carbonyl stress that leads to the formation of advanced glycation end products (AGEs) has drawn much attention recently because of its micro- and macrovascular implications. During monitoring of methylglyoxal (MG), the efficiency of phenolics to directly trap MG can be demonstrated. Twenty compds. consisting of a single benzene ring structure with the addn. of at least one hydroxyl group were allowed to react with MG at 37 °C for 1 h under physiol. conditions in pH 7.4 phosphate buffer soln. Compds. composed of a benzene structure with a mono-hydroxyl substitute cannot react with MG. Among benzenediols and di-hydroxyl benzoic acids, only hydroquinone reacted with MG and showed a 13% decrease in MG. Nevertheless, high reactivity was shown for 3 benzenetriols. The percentages of MG remaining were 45%, 51%, and 36% for pyrogallol, 1,2,4-trihydroxybenzene, and 1,3,5-trihydroxybenzene, resp. When a carboxyl group is added to the benzenetriols, steric hindrance and carbon electron charges on benzene ring are the influential factors in reactivity. Using computational chem. calcns., a carbon electron charge of -0.24 was the min. value for high reactivity.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXlt1Sit7w%253D&md5=61dfc8fa0f46322c6598df6eb60e8bde
    55. 55
      Shao, X.; Chen, H.; Zhu, Y.; Sedighi, R.; Ho, C.-T.; Sang, S. Essential Structural Requirements and Additive Effects for Flavonoids to Scavenge Methylglyoxal. J. Agric. Food Chem. 2014, 62, 3202– 3210,  DOI: 10.1021/jf500204s
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      55
      Essential Structural Requirements and Additive Effects for Flavonoids to Scavenge Methylglyoxal
      Shao, Xi; Chen, Huadong; Zhu, Yingdong; Sedighi, Rashin; Ho, Chi-Tang; Sang, Shengmin
      Journal of Agricultural and Food Chemistry (2014), 62 (14), 3202-3210CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      Reactive dicarbonyl species, such as methylglyoxal (MGO), are considered as the major precursors of advanced glycation end products (AGEs), which are believed to be one of the physiol. causes of diabetes and its complications. Scavenging of reactive dicarbonyl species using naturally occurring flavonoids has been proposed as an effective way to prevent diabetic complications. To elucidate the structural requirements of flavonoids in scavenging MGO, seven flavonoids (quercetin, luteolin, epicatechin, genistein, daidzein, apigenin, and phloretin) and five sub-components of the flavonoids (gallic acid, phloroglucinol, pyrogallol, pyrocatechol, and resorcinol) were examd. in this study. The results showed: (1) 1,2,3-trihydroxybenzene (pyrogallol) has higher MGO-scavenging activity than 1,3,5-trihydroxybenzene and 1,2- and 1,3-dihydroxybenzene, and substitution at position 5 of pyrogallol diminished the scavenging activity, indicating that position 5 is the active site of pyrogallol; (2) the A ring is the active site of flavonoids in contributing the MGO-trapping efficacy, and the hydroxyl group at C-5 on the A ring enhances the trapping efficacy; (3) the double bond between C-2 and C-3 on the C ring could facilitate the trapping efficacy; and (4) the no. of hydroxyl groups on the B ring does not significantly influence the trapping efficacy. In addn., the authors found there is an additive effect in MGO trapping by two common flavonoids, quercetin and phloretin, indicating that flavonoid-enriched foods and beverages may be used to prevent the development of diabetic complications.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXkslSgsLk%253D&md5=3a65956cd71c4019be5192a0d507756b
    56. 56
      Hidalgo, F. J.; Aguilar, I.; Zamora, R. Model Studies on the Effect of Aldehyde Structure on Their Selective Trapping by Phenolic Compounds. J. Agric. Food Chem. 2017, 65, 4736– 4743,  DOI: 10.1021/acs.jafc.7b01081
      [ACS Full Text ACS Full Text], [CAS], Google Scholar
      56
      Model Studies on the Effect of Aldehyde Structure on Their Selective Trapping by Phenolic Compounds
      Hidalgo, Francisco J.; Aguilar, Isabel; Zamora, Rosario
      Journal of Agricultural and Food Chemistry (2017), 65 (23), 4736-4743CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)
      The reaction among flavor-relevant satd. aldehydes (propanal, 2-methylpropanal, butanal, 2-methylbutanal, 3-methylbutanal, pentanal, hexanal, and glyoxal) and phenolic compds. (resorcinol, 2-methylresorcinol, 2,5-dimethylresorcinol, and orcinol) was studied both to identify and characterize the formed carbonyl-phenol adducts and to understand the differences in the carbonyl-trapping abilities of phenolic compds. The obtained results showed that carbonyl-trapping by phenolics is selective and the formation of carbonyl-phenol adducts depends on the structure of both phenol and aldehyde involved. In relation to the phenolic deriv., the presence of groups that increase the nucleophilicity of phenolic carbons will increase the carbonyl-trapping ability of these compds. On the other hand, the presence of groups that increase the steric hindrance of these positions without affecting nucleophilia, will inhibit the reaction. Analogously, the presence of branching at position 2 of the aldehyde will also inhibit the reaction by steric hindrance. All these results suggest that addn. of phenolics to foods may change food flavor not only because of their sensory properties but also because they can modify the ratio among food odorants by selective reaction of phenolics with detd. carbonyl compds.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXotFOkt70%253D&md5=231b3f0d7a6e0ad682e6c5ba65e4dd13
    57. 57
      Capuano, E.; Oliviero, T.; van Boekel, M. A. J. S. Modeling Food Matrix Effects on Chemical Reactivity: Challenges and Perspectives. Crit. Rev. Food Sci. Nutr. 2018, 58, 2814– 2828,  DOI: 10.1080/10408398.2017.1342595
      [Crossref], [PubMed], [CAS], Google Scholar
      57
      Modeling food matrix effects on chemical reactivity: Challenges and perspectives
      Capuano, Edoardo; Oliviero, Teresa; van Boekel, Martinus A. J. S.
      Critical Reviews in Food Science and Nutrition (2018), 58 (16), 2814-2828CODEN: CRFND6; ISSN:1040-8398. (Taylor & Francis, Inc.)
      The same chem. reaction may be different in terms of its position of the equil. (i.e., thermodn.) and its kinetics when studied in different foods. The diversity in the chem. compn. of food and in its structural organization at macro-, meso-, and microscopic levels, i.e., the food matrix, is responsible for this difference. In this viewpoint paper, the multiple, and interconnected ways the food matrix can affect chem. reactivity are summarized. Moreover, mechanistic and empirical approaches to explain and predict the effect of food matrix on chem. reactivity are described. Mechanistic models aim to quantify the effect of food matrix based on a detailed understanding of the chem. and phys. phenomena occurring in food. Their applicability is limited at the moment to very simple food systems. Empirical modeling based on machine learning combined with data-mining techniques may represent an alternative, useful option to predict the effect of the food matrix on chem. reactivity and to identify chem. and phys. properties to be further tested. In such a way the mechanistic understanding of the effect of the food matrix on chem. reactions can be improved.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsVarsL3F&md5=1f79e27bfbee53ae850df9ee8a1612ac

  • Supporting Information

    Supporting Information

    ARTICLE SECTIONS
    Jump To

    The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.jafc.9b03744.

    • Chromatograms of the (A) standard mixture, (B) saline-treated HMW-CM, (C) acid-hydrolyzed HMW-CM, and (D) alkali-hydrolyzed HMW-CM; dose-dependent results for GO, MGO, and DA trapping capacities (168 h) of CA, 3-CQA, and FA (0.128-0.853 mmol/L); and main fragmentation patterns of CA (A), mono-MGO-CA (B), and di-MGO-CA (C) in the negative-ion mode (PDF)


    Terms & Conditions

    Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

PDF [ 1MB]

Pair your accounts.

Export articles to Mendeley

Get article recommendations from ACS based on references in your Mendeley library.

Pair your accounts.

Export articles to Mendeley

Get article recommendations from ACS based on references in your Mendeley library.

You’ve supercharged your research process with ACS and Mendeley!

STEP 1:
Click to create an ACS ID

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

MENDELEY PAIRING EXPIRED
Your Mendeley pairing has expired. Please reconnect