Detailed Characterization of the Conversion of Hardwood and Softwood Lignin by a Brown-Rot BasidiomyceteClick to copy article linkArticle link copied!
- Morten ReseMorten ReseFaculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, Ås 1433, NorwayMore by Morten Rese
- Gijs van ErvenGijs van ErvenWageningen Food and Biobased Research, Bornse Weilanden 9, Wageningen 6708 WG, The NetherlandsLaboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, Wageningen 6708 WG, The NetherlandsMore by Gijs van Erven
- Romy J. VeersmaRomy J. VeersmaLaboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, Wageningen 6708 WG, The NetherlandsMore by Romy J. Veersma
- Gry AlfredsenGry AlfredsenDepartment of Wood Technology, Norwegian Institute of Bioeconomy Research, P.O. Box 115, Ås NO-1431, NorwayMore by Gry Alfredsen
- Vincent G. H. EijsinkVincent G. H. EijsinkFaculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, Ås 1433, NorwayMore by Vincent G. H. Eijsink
- Mirjam A. KabelMirjam A. KabelLaboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, Wageningen 6708 WG, The NetherlandsMore by Mirjam A. Kabel
- Tina R. Tuveng*Tina R. Tuveng*Email: [email protected]Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, Ås 1433, NorwayMore by Tina R. Tuveng
Abstract
Wood-degrading brown-rot fungi primarily target carbohydrates, leaving the lignin modified and potentially valuable for valorization. Here, we report a comprehensive comparison of how Gloeophyllum trabeum in vitro degrades hardwood and softwood, which have fundamentally different lignin structures. By harnessing the latest advancements in analytical methodologies, we show that G. trabeum removes more lignin from wood (up to 36%) than previously reported. The brown-rot decayed lignin appeared substantially Cα-oxidized, O-demethylated, with a reduction in interunit linkages, leading to formation of substructures indicative of Cα-Cβ, β-O, and O-4 cleavage. Our work shows that the G. trabeum conversion of hardwood and softwood lignin results in similar modifications, despite the structural differences. Furthermore, lignin modification by G. trabeum enhances the antioxidant capacity of the lignin and generates an extractable lower molecular weight fraction. These findings improve our understanding of lignin conversion by brown-rot fungi and highlight their biotechnological potential for the development of lignin-based products.
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Introduction
Materials and Methods
Brown-Rot Decay of Wood
Sound Wood Samples
Compositional Analysis
Quantitative 13C-IS-Pyrolysis-GC-MS
Isolation of Lignin for Detailed Structural Characterization
Sequential Solvent Fractionation of Brown-Rot Decayed Spruce and Birch
Brown-Rot Decayed Spruce and Birch Lignin Acetylation
2D-HSQC NMR Spectroscopy
31P NMR Spectroscopy
Size-Exclusion Chromatography (SEC)
Antioxidant Capacity Assay
Results and Discussion
Carbohydrate and Lignin Removal
Figure 1
Figure 1. Compositional analysis of spruce and birch. (A) The content of protein, acid soluble lignin (ASL), acid insoluble lignin (AIL), and carbohydrates in spruce and birch, as percentage of the total mass, determined before and after 18 weeks of brown-rot (BR) decay. (B) Removal of carbohydrates and lignin from spruce and birch after brown-rot decay, calculated based on contents analyzed (w/w%; Table S3) combined with the total gravimetric dry mass removal. Lignin was quantified with gravimetric Klason methodology (Lignin - Klason; sum of ASL and AIL) and 13C-IS pyrolysis-GC-MS (Lignin - py-GC-MS). Error bars represent standard deviation (n = 3).
Structural Characterization of G. trabeum Decayed Wood
13C-IS py-GC-MS Analyses Indicate Extensive Oxidation and Demethylation
Lignin subunits (%) | Sound spruce | BR spruce | Sound birch | BR birch |
---|---|---|---|---|
H | 1.3 ± 0.1 | 1.3 ± 0.0 | 0.9 ± 0.1 | 0.7 ± 0.0 |
G | 97.1 ± 0.3 | 98.4 ± 0.0 | 25.7 ± 1.0 | 25.9 ± 0.2 |
S | 1.6 ± 0.4 | 0.2 ± 0.0 | 73.4 ± 1.1 | 73.5 ± 0.2 |
Structural moieties (%) | ||||
Unsubstituted | 5.8 ± 0.1 | 7.0 ± 0.2 | 3.9 ± 0.1 | 4.8 ± 0.5 |
Methyl | 5.0 ± 0.2 | 4.6 ± 0.1 | 2.6 ± 0.1 | 2.0 ± 0.1 |
Vinyl | 15.2 ± 0.2 | 15.5 ± 0.5 | 11.0 ± 0.2 | 8.7 ± 0.7 |
Cα – oxb | 4.7 ± 0.1 | 9.0 ± 0.3 | 6.5 ± 0.0 | 10.0 ± 0.5 |
Vanillin | 2.3 ± 0.1 | 4.6 ± 0.1 | 0.7 ± 0.0 | 1.0 ± 0.0 |
Acetovanillone | 1.1 ± 0.0 | 1.4 ± 0.0 | 0.3 ± 0.0 | 0.4 ± 0.0 |
Guaiacyl diketone | 0.6 ± 0.0 | 2.1 ± 0.1 | 0.2 ± 0.0 | 0.6 ± 0.0 |
Syringaldehyde | 0.1 ± 0.0 | n.d. | 3.0 ± 0.0 | 3.8 ± 0.2 |
Acetosyringone | n.d. | n.d. | 1.0 ± 0.0 | 1.3 ± 0.1 |
Syringyl diketone | n.d. | n.d. | 0.8 ± 0.0 | 1.8 ± 0.1 |
Cβ – oxb | 2.3 ± 0.0 | 3.1 ± 0.0 | 2.0 ± 0.2 | 2.2 ± 0.1 |
Cγ – oxb | 61.8 ± 0.4 | 56.9 ± 1.2 | 69.0 ± 0.3 | 68.5 ± 2.1 |
Miscellaneous | 5.3 ± 0.1 | 3.9 ± 0.1 | 5.1 ± 0.1 | 3.8 ± 0.3 |
PhCγc | 68.6 ± 0.4 | 64.2 ± 1.0 | 76.4 ± 0.3 | 76.4 ± 1.7 |
PhCγ -diketonesd | 68.4 ± 0.4 | 63.4 ± 1.0 | 76.2 ± 0.3 | 75.8 ± 1.7 |
For a comprehensive list of all monitored pyrolysis products and their respective categories, see Table S1. Numbers are averages of triplicates with standard deviation. Standard deviations <0.05 are reported as 0.0 n.d: not detected.
Pyrolysis products oxidized on carbon α, β, or γ.
Pyrolysis products with an intact α, β, γ – carbon side chain. “Ph” refers to the phenyl group (C6H5).
PhCγ with diketones excluded.
HSQC NMR Analysis Confirms the Results Obtained with 13C-IS py-GC-MS
Figure 2
Figure 2. HSQC NMR spectra of lignin isolates of sound and brown-rot decayed wood. The spectra show the aliphatic (A) and aromatic (B) regions for lignin isolated (through enzymatic treatment) from sound and brown-rot decayed spruce and birch. Subscripted numbers and Greek letters in annotations indicate which carbon in the annotated substructure the signal originates from. (C) Annotated substructures, where colors correspond to colored signals in A and B. Dashed lines indicate -H (guaiacyl) or -OCH3(syringyl), while the main position for further coupling is indicated with wavy lines. Unassigned peaks are shown in gray.
Subunits (%) | Sound spruce | BR spruce | Sound birch | BR birch |
---|---|---|---|---|
G | 87.6 | 75.1 | 22.5 | 23.5 |
Gox | 4.6 | 10.3 | 0.3 | 0.8 |
Gcond | 7.9 | 14.6 | 0.0 | 0.0 |
S | 0.0 | 0.0 | 69.1 | 54.0 |
Sox | 0.0 | 0.0 | 8.1 | 10.8 |
MC | 0.0 | 0.0 | 0.0 | 9.2 |
MCox | 0.0 | 0.0 | 0.0 | 1.7 |
S/G | - | - | 3.4 | 2.7 |
Interunit linkages (per 100 ar) | ||||
β-O-4 aryl ether | 30.6 | 30.3 | 62.3 | 49.6 |
β-5 phenylcoumaran | 8.6 | 10.0 | 1.7 | 1.8 |
β–β resinol | 2.8 | 2.7 | 5.7 | 6.9 |
β-1 spirodienone | 0.0 | 0.0 | 2.2 | 0.0 |
5–5/4-O-β dibenzodioxocin | 2.2 | 0.8b | 0.0 | 0.0 |
End units (per 100 ar) | ||||
Cinnamyl alcohol | 3.1 | 1.3 | 1.7 | 1.3 |
Cinnamaldehyde | 5.1 | 3.5 | 2.0 | 2.9 |
Arylglycerol | 0.0 | 0.0 | 0.0 | 2.3 |
Benzaldehyde | 2.0 | 6.3 | 0.3 | 1.6 |
HPV/HPS | 0.8 | 0.9 | 0.3 | 0.7 |
DHPV/DHPS | 0.9 | 3.3 | 0.0 | 1.4 |
Ring substituents (per 100 ar) | ||||
Methoxyl | 134.6 (127.5)c | 122.1(103.4)c | 183.2 | 167.2 |
Gox/Sox: guaiacyl/syringyl units oxidized on the Cα-carbon, Gcond: guaiacyl units involved in condensed linkages, MC: methoxycatechyl units, MCox: methoxycatechyl units oxidized on the Cα-carbon,HPV/HPS: hydroxypropiovanillone/hydroxypropiosyringone,DHPV/DHPS: dihydroxypropiovanillone/dihydroxypropiosyringone. “ar” refers to aromatic rings
Integrated at 2x zoomed counter level.
Values in parentheses based on total aromatic region to account for C2, C5, C6, G5, G6 overlap.
Figure 3
Figure 3. HSQC NMR spectra of acetylated lignin isolates of brown-rot decayed wood. The spectra show the aliphatic and aromatic regions for acetylated, brown-rot decayed spruce (A) and birch (B). Subscripted numbers and Greek letters in annotations indicate which carbon in the annotated substructure the signal originates from. Inset values present lignin component ratios determined from contour volume integrals (top: per 100 aromatic rings, bottom: relative). (C) Annotated substructures, where colors correspond to colored signals in the spectra. Dashed lines indicate -H (guaiacyl) or -OCH3 (syringyl), while the main position for further coupling is indicated with wavy lines. Unassigned peaks are shown in gray.
Interunit Oxidative Cleavage Occurs in β-O-4 Aryl Ethers
Valorization Potential of Brown-Rot Decayed Lignin
Conclusions
Supporting Information
The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.biomac.4c01403.
Development of G. trabeum mycelium on wood blocks; mass loss of spruce and birch wood blocks; determination of lignin content; 13C-IS pyrolysis-GC-MS abundance of catechol/methoxycatechol pyrolysis products; aromatic regions of HSQC NMR spectra of sound and brown-rot decayed wood; quantitative 31P NMR spectra; SEC elution profiles; antioxidant capacity assay; relative mass of fractions after sequential solvent fractionation; HQSC NMR spectra of acetone/H2O extracts of brown-rot decayed wood; composition of carbohydrates, lignin, and protein in sound and brown-rot decayed wood; composition of structural carbohydrates in sound and brown-rot decayed wood; identity and structural classification of lignin-derived pyrolysis products detected; annotation of catechol and methoxycatechol pyrolysis products; molecular weight distribution of brown-rot decayed spruce and birch lignin isolates, and acetone/H2O extracts of these; structural characterization of acetone/H2O extracts of brown-rot decayed spruce and birch (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.
Acknowledgments
The authors thank Thales de Freitas Costa (NMBU) for technical help and discussions regarding the compositional analysis. This work was supported by the Research Council of Norway (grant no. 325376).
AIL | acid insoluble lignin |
ASL | acid soluble lignin |
BR | brown rot |
HSQC NMR | heteronuclear single-quantum coherence nuclear magnetic resonance |
MS | mass spectrometry |
13C-IS-py-GC-MS | pyrolysis gas chromatography–mass spectrometry with uniformly, 13Carbon-labeled lignin as an internal standard |
SEC | size-exclusion chromatography |
TEAC | trolox equivalent antioxidant capacity. |
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- 10Dashtban, M.; Schraft, H.; Syed, T. A.; Qin, W. Fungal Biodegradation and Enzymatic Modification of Lignin. Int. J. Biochem. Mol. Biol. 2010, 1 (1), 36– 50Google Scholar10https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXitlOrurs%253D&md5=e29660b235d6306ce814933a9fbc6fc1Fungal biodegradation and enzymatic modification of ligninDashtban, Mehdi; Schraft, Heidi; Syed, Tarannum A.; Qin, WenshengInternational Journal of Biochemistry and Molecular Biology (2010), 1 (1), 36-50CODEN: IJBMHV; ISSN:2152-4114. (e-Century Publishing Corp.)A review. Lignin, the most abundant arom. biopolymer on Earth, is extremely recalcitrant to degrdn. By linking to both hemicellulose and cellulose, it creates a barrier to any solns. or enzymes and prevents the penetration of lignocellulolytic enzymes into the interior lignocellulosic structure. Some basidiomycetes white-rot fungi are able to degrade lignin efficiently using a combination of extracellular ligninolytic enzymes, org. acids, mediators and accessory enzymes. This review describes ligninolytic enzyme families produced by these fungi that are involved in wood decay processes, their mol. structures, biochem. properties and the mechanisms of action which render them attractive candidates in biotechnol. applications. These enzymes include phenol oxidase (laccase) and heme peroxidases [lignin peroxidase (LiP), manganese peroxidase (MnP) and versatile peroxidase (VP)]. Accessory enzymes such as H2O2-generating oxidases and degrdn. mechanisms of plant cell-wall components in a non-enzymic manner by prodn. of free hydroxyl radicals (·OH) are also discussed.
- 11Martínez, A. T. Molecular Biology and Structure-Function of Lignin-Degrading Heme Peroxidases. Enzyme Microb. Technol. 2002, 30 (4), 425– 444, DOI: 10.1016/S0141-0229(01)00521-XGoogle Scholar11https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38Xis1Oru7k%253D&md5=c15ddedae82e5d17170c35463b90e422Molecular biology and structure-function of lignin-degrading heme peroxidasesMartinez, Angel T.Enzyme and Microbial Technology (2002), 30 (4), 425-444CODEN: EMTED2; ISSN:0141-0229. (Elsevier Science Ireland Ltd.)A review. Three peroxidases involved in lignin degrdn. are produced by white-rot fungi. Lignin peroxidase (LiP) is characterized by oxidn. of high redox-potential arom. compds. (including veratryl alc.) whereas manganese peroxidase (MnP) requires Mn2+ to complete the catalytic cycle and forms Mn3+ chelates acting as diffusing oxidizers. Pleurotus and Bjerkandera versatile peroxidase (VP) is able to oxidize Mn2+ as well as nonphenolic arom. compds., phenols and dyes. Phanerochaete chrysosporium has two gene families including ten LiP-type and three MnP-type genes coding different isoenzymes expressed during secondary metab. Two VP genes have been recently cloned from Pleurotus eryngii. Phanerochaete chrysosporium MnP and P. eryngii VP are induced by H2O2, being Mn2+ involved in regulation of their transcript levels. At least eighteen more ligninolytic peroxidase genes have been cloned from other white-rot fungi. Protein sequence comparison reveals that typical MnP from P. chrysosporium and two other fungi (showing a longer C-terminal tail) are sepd. from other ligninolytic peroxidases, which form two main groups including P. chrysosporium LiP and Pleurotus peroxidases, resp. LiP and MnP crystal structures and VP theor. mol. models are available. The high redox potential of ligninolytic peroxidases seems related to the distance between heme iron and proximal histidine, and the ability of MnP to oxidize Mn2+ is due to a Mn-binding site formed by three acidic residues near the internal heme propionate. Pleurotus eryngii VP show higher sequence and structural affinities with P. chrysosporium LiP than MnP, but includes a Mn-binding site accounting for its ability to oxidize Mn2+. The functionality of this site was demonstrated by site-directed mutagenesis of MnP and VP. All fungal peroxidases, which exhibit similar topol. (11-12 helixes) and folding, also include binding sites for two structural Ca2+. Veratryl alc. was first modeled near LiP heme, but evidence for oxidn. at the protein surface via a long-range electron transfer pathway has accumulated. Chem. and site-directed mutagenesis modification confirmed that an exposed tryptophan is involved in veratryl alc. oxidn. however, multiple sites could be responsible for oxidn. of different arom. substrates and dyes by these peroxidases.
- 12Fernandez-Fueyo, E.; Ruiz-Duenas, F. J.; Ferreira, P.; Floudas, D.; Hibbett, D. S.; Canessa, P.; Larrondo, L. F.; James, T. Y.; Seelenfreund, D.; Lobos, S.; Polanco, R.; Tello, M.; Honda, Y.; Watanabe, T.; Watanabe, T.; San, R. J.; Kubicek, C. P.; Schmoll, M.; Gaskell, J.; Hammel, K. E.; St John, F. J.; Vanden Wymelenberg, A.; Sabat, G.; BonDurant, S. S.; Syed, K.; Yadav, J. S.; Doddapaneni, H.; Subramanian, V.; Lavin, J. L.; Oguiza, J. A.; Perez, G.; Pisabarro, A. G.; Ramirez, L.; Santoyo, F.; Master, E.; Coutinho, P. M.; Henrissat, B.; Lombard, V.; Magnuson, J. K.; Kues, U.; Hori, C.; Igarashi, K.; Samejima, M.; Held, B. W.; Barry, K. W.; LaButti, K. M.; Lapidus, A.; Lindquist, E. A.; Lucas, S. M.; Riley, R.; Salamov, A. A.; Hoffmeister, D.; Schwenk, D.; Hadar, Y.; Yarden, O.; de Vries, R. P.; Wiebenga, A.; Stenlid, J.; Eastwood, D.; Grigoriev, I. V.; Berka, R. M.; Blanchette, R. A.; Kersten, P.; Martínez, A. T.; Vicuna, R.; Cullen, D. Comparative Genomics of Ceriporiopsis Subvermispora and Phanerochaete Chrysosporium Provide Insight into Selective Ligninolysis. Proc. Natl. Acad. Sci. U. S. A. 2012, 109 (14), 5458– 5463, DOI: 10.1073/pnas.1119912109Google ScholarThere is no corresponding record for this reference.
- 13Martínez, A. T.; Ruiz-Duenas, F. J.; Martínez, M. J.; Del Río, J. C.; Gutiérrez, A. Enzymatic Delignification of Plant Cell Wall: From Nature to Mill. Curr. Opin. Biotechnol. 2009, 20 (3), 348– 357, DOI: 10.1016/j.copbio.2009.05.002Google Scholar13https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXosVajtro%253D&md5=3c1ebfcd7c7e1d8c5e7fa43618025705Enzymatic delignification of plant cell wall: From nature to millMartinez, Angel T.; Ruiz-Duenas, Francisco J.; Martinez, Maria Jesus; del Rio, Jose C.; Gutierrez, AnaCurrent Opinion in Biotechnology (2009), 20 (3), 348-357CODEN: CUOBE3; ISSN:0958-1669. (Elsevier B.V.)A review. Lignin removal is a central issue in paper pulp manuf., and prodn. of other renewable chems., materials, and biofuels in future lignocellulose biorefineries. Biotechnol. can contribute to more efficient and environmentally sound deconstruction of plant cell wall by providing tailor-made biocatalysts based on the oxidative enzymes responsible for lignin attack in Nature. With this purpose, the already-known ligninolytic oxidoreductases are being improved using (rational and random-based) protein engineering, and still unknown enzymes will be identified by the application of the different "omics" technologies. Enzymic delignification will be soon at the pulp mill (combined with pitch removal) and our understanding of the reactions produced will increase by using modern techniques for lignin anal.
- 14Martínez, A. T.; Speranza, M.; Ruiz-Duenas, F. J.; Ferreira, P.; Camarero, S.; Guillen, F.; Martínez, M. J.; Gutiérrez, A.; Del Río, J. C. Biodegradation of Lignocellulosics: Microbial, Chemical, and Enzymatic Aspects of the Fungal Attack of Lignin. Int. Microbiol. 2005, 8 (3), 195– 204Google Scholar14https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXhtVemt7vL&md5=89d984d69398efe52208f415afc8419aBiodegradation of lignocellulosics: Microbial, chemical, and enzymatic aspects of the fungal attack of ligninMartinez, Angel T.; Speranza, Mariela; Ruiz-Duenas, Francisco J.; Ferreira, Patricia; Camarero, Susana; Guillen, Francisco; Martinez, Maria J.; Gutierrez, Ana; del Rio, Jose C.International Microbiology (2005), 8 (3), 195-204CODEN: INMIFW; ISSN:1139-6709. (Viguera Editores)A review. Wood is the main renewable material on Earth and is largely used as building material and in paper-pulp manufg. This review describes the compn. of lignocellulosic materials, the different processes by which fungi are able to alter wood, including decay patterns caused by white, brown, and soft-rot fungi, and fungal staining of wood. The chem., enzymic, and mol. aspects of the fungal attack of lignin, which represents the key step in wood decay, are also discussed. Modern anal. techniques to investigate fungal degrdn. and modification of the lignin polymer are reviewed, as are the different oxidative enzymes (oxidoreductases) involved in lignin degrdn. These include laccases, high redox potential ligninolytic peroxidases (lignin peroxidase, manganese peroxidase, and versatile peroxidase), and oxidases. Special emphasis is given to the reactions catalyzed, their synergistic action on lignin, and the structural bases for their unique catalytic properties. Broadening our knowledge of lignocellulose biodegrdn. processes should contribute to better control of wood-decaying fungi, as well as to the development of new biocatalysts of industrial interest based on these organisms and their enzymes.
- 15Eastwood, D. C.; Floudas, D.; Binder, M.; Majcherczyk, A.; Schneider, P.; Aerts, A.; Asiegbu, F. O.; Baker, S. E.; Barry, K.; Bendiksby, M.; Blumentritt, M.; Coutinho, P. M.; Cullen, D.; De Vries, R. P.; Gathman, A.; Goodell, B.; Henrissat, B.; Ihrmark, K.; Kauserud, H.; Kohler, A.; LaButti, K.; Lapidus, A.; Lavin, J. L.; Lee, Y. H.; Lindquist, E.; Lilly, W.; Lucas, S.; Morin, E.; Murat, C.; Oguiza, J. A.; Park, J.; Pisabarro, A. G.; Riley, R.; Rosling, A.; Salamov, A.; Schmidt, O.; Schmutz, J.; Skrede, I.; Stenlid, J.; Wiebenga, A.; Xie, X.; Kues, U.; Hibbett, D. S.; Hoffmeister, D.; Hogberg, N.; Martin, F.; Grigoriev, I. V.; Watkinson, S. C. The Plant Cell Wall-Decomposing Machinery Underlies the Functional Diversity of Forest Fungi. Science 2011, 333 (6043), 762– 765, DOI: 10.1126/science.1205411Google ScholarThere is no corresponding record for this reference.
- 16Kerem, Z.; Jensen, K. A.; Hammel, K. E. Biodegradative Mechanism of the Brown Rot Basidiomycete Gloeophyllum Trabeum: Evidence for an Extracellular Hydroquinone-Driven Fenton Reaction. FEBS Lett. 1999, 446 (1), 49– 54, DOI: 10.1016/S0014-5793(99)00180-5Google ScholarThere is no corresponding record for this reference.
- 17Suzuki, M. R.; Hunt, C. G.; Houtman, C. J.; Dalebroux, Z. D.; Hammel, K. E. Fungal Hydroquinones Contribute to Brown Rot of Wood. Environ. Microbiol. 2006, 8 (12), 2214– 2223, DOI: 10.1111/j.1462-2920.2006.01160.xGoogle ScholarThere is no corresponding record for this reference.
- 18Kijpornyongpan, T.; Schwartz, A.; Yaguchi, A.; Salvachúa, D. Systems Biology-Guided Understanding of White-Rot Fungi for Biotechnological Applications. A Review. iScience 2022, 25 (7), 104640 DOI: 10.1016/j.isci.2022.104640Google ScholarThere is no corresponding record for this reference.
- 19Riley, R.; Salamov, A. A.; Brown, D. W.; Nagy, L. G.; Floudas, D.; Held, B. W.; Levasseur, A.; Lombard, V.; Morin, E.; Otillar, R.; Lindquist, E. A.; Sun, H.; LaButti, K. M.; Schmutz, J.; Jabbour, D.; Luo, H.; Baker, S. E.; Pisabarro, A. G.; Walton, J. D.; Blanchette, R. A.; Henrissat, B.; Martin, F.; Cullen, D.; Hibbett, D. S.; Grigoriev, I. V. Extensive Sampling of Basidiomycete Genomes Demonstrates Inadequacy of the White-Rot/Brown-Rot Paradigm for Wood Decay Fungi. Proc. Natl. Acad. Sci. U. S. A. 2014, 111 (27), 9923– 9928, DOI: 10.1073/pnas.1400592111Google ScholarThere is no corresponding record for this reference.
- 20Martinez, A. T.; Rencoret, J.; Nieto, L.; Jimenez-Barbero, J.; Gutierrez, A.; Del Rio, J. C. Selective Lignin and Polysaccharide Removal in Natural Fungal Decay of Wood as Evidenced by in Situ Structural Analyses. Environ. Microbiol. 2011, 13 (1), 96– 107, DOI: 10.1111/j.1462-2920.2010.02312.xGoogle ScholarThere is no corresponding record for this reference.
- 21Yelle, D. J.; Ralph, J.; Lu, F.; Hammel, K. E. Evidence for Cleavage of Lignin by a Brown Rot Basidiomycete. Environ. Microbiol. 2008, 10 (7), 1844– 1849, DOI: 10.1111/j.1462-2920.2008.01605.xGoogle Scholar21https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXptVKgt7w%253D&md5=4bd3302894b0aa376a9038704fc36b4aEvidence for cleavage of lignin by a brown rot basidiomyceteYelle, Daniel J.; Ralph, John; Lu, Fachuang; Hammel, Kenneth E.Environmental Microbiology (2008), 10 (7), 1844-1849CODEN: ENMIFM; ISSN:1462-2912. (Blackwell Publishing Ltd.)Biodegrdn. by brown-rot fungi is quant. one of the most important fates of lignocellulose in nature. It has long been thought that these basidiomycetes do not degrade lignin significantly, and that their activities on this abundant arom. biopolymer are limited to minor oxidative modifications. Here we have applied a new technique for the complete solubilization of lignocellulose to show, by one-bond 1H-13C correlation NMR spectroscopy, that brown rot of spruce wood by Gloeophyllum trabeum resulted in a marked, non-selective depletion of all intermonomer side-chain linkages in the lignin. The resulting polymer retained most of its original arom. residues and was probably interconnected by new linkages that lack hydrogens and are consequently invisible in one-bond 1H-13C correlation spectra. Addnl. work is needed to characterize these linkages, but it is already clear that the arom. polymer remaining after extensive brown rot is no longer recognizable as lignin.
- 22Yelle, D. J.; Wei, D.; Ralph, J.; Hammel, K. E. Multidimensional NMR Analysis Reveals Truncated Lignin Structures in Wood Decayed by the Brown Rot Basidiomycete Postia Placenta. Environ. Microbiol. 2011, 13 (4), 1091– 1100, DOI: 10.1111/j.1462-2920.2010.02417.xGoogle Scholar22https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXmtV2jtrg%253D&md5=1b2ce8f5f064867f2ec261f46b7a4170Multidimensional NMR analysis reveals truncated lignin structures in wood decayed by the brown rot basidiomycete Postia placentaYelle, Daniel J.; Wei, Dongsheng; Ralph, John; Hammel, Kenneth E.Environmental Microbiology (2011), 13 (4), 1091-1100CODEN: ENMIFM; ISSN:1462-2912. (Wiley-Blackwell)Lignocellulose biodegrdn., an essential step in terrestrial carbon cycling, generally involves removal of the recalcitrant lignin barrier that otherwise prevents infiltration by microbial polysaccharide hydrolases. However, fungi that cause brown rot of wood, a major route for biomass recycling in coniferous forests, utilize wood polysaccharides efficiently while removing little of the lignin. The mechanism by which these basidiomycetes breach the lignin remains unclear. We used recently developed methods for solubilization and multidimensional 1H-13C soln.-state NMR spectroscopy of ball-milled lignocellulose to analyze aspen wood degraded by Postia placenta. The results showed that decay decreased the content of the principal arylglycerol-β-aryl ether linkage in the lignin by more than half, while increasing the frequency of several truncated lignin structures roughly fourfold over the level found in sound aspen. These new end-groups, consisting of benzaldehydes, benzoic acids and phenylglycerols, accounted for 6-7% of all original lignin subunits. Our results provide evidence that brown rot by P. placenta results in significant ligninolysis, which might enable infiltration of the wood by polysaccharide hydrolases even though the partially degraded lignin remains in situ. Recent work has revealed that the P. placenta genome encodes no ligninolytic peroxidases, but has also shown that this fungus produces an extracellular Fenton system. It is accordingly likely that P. placenta employs electrophilic reactive oxygen species such as hydroxyl radicals to disrupt lignin in wood.
- 23Filley, T. R.; Cody, G. D.; Goodell, B.; Jellison, J.; Noser, C.; Ostrofsky, A. Lignin Demethylation and Polysaccharide Decomposition in Spruce Sapwood Degraded by Brown Rot Fungi. Org. Geochem. 2002, 33 (2), 111– 124, DOI: 10.1016/S0146-6380(01)00144-9Google Scholar23https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XhtFyktrc%253D&md5=12a528ca0226cf1a316268bfa763524fLignin demethylation and polysaccharide decomposition in spruce sapwood degraded by brown rot fungiFilley, T. R.; Cody, G. D.; Goodell, B.; Jellison, J.; Noser, C.; Ostrofsky, A.Organic Geochemistry (2002), 33 (2), 111-124CODEN: ORGEDE; ISSN:0146-6380. (Elsevier Science Ltd.)The org. residues produced in the brown-rot (BR) of wood by many basidiomycetes fungi are ubiquitous on most coniferous forest floors. This degraded wood tissue is characterized by low levels of polysaccharides and a high proportion of demethylated lignin with minor glycerol side-chain oxidn. Because of the selective enrichment in an arom. dihydroxy-rich lignin residue, the chem. and biol. reactivity of BR-degraded wood will be distinctly different from white rot, the other primary class of fungal wood decay, which typically produces oxidized, lignin-depleted residues. The biochem. mechanism by which BR fungi perform this distinctive degradative chem. is only starting to become known, and mol. studies which examine the chem. changes imparted to lignin over the long-term decay process are lacking. Using 13C-labeled tetramethylammonium hydroxide thermochemolysis (13C-TMAH) and solid-state 13C NMR, the authors investigated the relation between lignin oxidn./demethylation and polysaccharide metab. in a 32-wk time series study of spruce sapwood inoculated with either of two BR fungi (Postia placenta and Gloeophyllum trabeum). The findings demonstrate a close relation between lignin demethylation and polysaccharide loss and suggest demethylation may play a mechanistic role in polysaccharide loss, possibly by assisting in Fenton reactions where catechol/quinone oxidn. and cycling aids in iron redn. The residue remaining after 16 wk of decay is devoid of polysaccharides, in contrast to the 68% polysaccharide carbon present in the initial spruce, and exhibits an increased arom. dihydroxy content (resulting from demethylation of the 3-methoxyl carbon) of up to 22% of the lignin, as detd. by 13C-TMAH thermochemolysis. In a typical soil or porewater environment these chem. changes would make BR residues highly reactive toward redox-sensitive polyvalent metals (e.g. ferric iron) and likely to adsorb to metal hydroxide surfaces.
- 24Koenig, A. B.; Sleighter, R. L.; Salmon, E.; Hatcher, P. G. NMR Structural Characterization of Quercus Alba (White Oak) Degraded by the Brown Rot Fungus. Laetiporus Sulphureus. J. Wood Chem. Technol. 2010, 30 (1), 61– 85, DOI: 10.1080/02773810903276668Google ScholarThere is no corresponding record for this reference.
- 25Qi, J.; Jia, L.; Liang, Y.; Luo, B.; Zhao, R.; Zhang, C.; Wen, J.; Zhou, Y.; Fan, M.; Xia, Y. Fungi’s Selectivity in the Biodegradation of Dendrocalamus Sinicus Decayed by White and Brown Rot Fungi. Ind. Crops Prod. 2022, 188, 115726 DOI: 10.1016/j.indcrop.2022.115726Google ScholarThere is no corresponding record for this reference.
- 26Brinkmann, K.; Blaschke, L.; Polle, A. Comparison of Different Methods for Lignin Determination as a Basis for Calibration of near-Infrared Reflectance Spectroscopy and Implications of Lignoproteins. J. Chem. Ecol. 2002, 28 (12), 2483– 2501, DOI: 10.1023/A:1021484002582Google ScholarThere is no corresponding record for this reference.
- 27Hatfield, R.; Fukushima, R. S. Can Lignin Be Accurately Measured?. Crop Sci. 2005, 45 (3), 832– 839, DOI: 10.2135/cropsci2004.0238Google Scholar27https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXks1Wrurk%253D&md5=67c1f208b4a29d4864c4c360de13aa29Can lignin be accurately measured?Hatfield, Ronald; Fukushima, Romualdo S.Crop Science (2005), 45 (3), 832-839CODEN: CRPSAY; ISSN:0011-183X. (Crop Science Society of America)A review. Forages serve an important role in providing nutrients to ruminants while providing pos. benefits to the environment. Forage cell wall digestibility is incomplete because of several structural features within the wall, but digestion is mostly inversely correlated with the amt. of lignification that has occurred during cell wall development. Lignin is a hydrophobic polymer formed through enzyme-mediated radical coupling of monolignols, mainly coniferyl and sinapyl alcs. The polymer is highly resistant to degrdn. and generally passes through the ruminant unmodified. Though lignin is resistant to degrdn., it is not easily quantified within various types of forages. Numerous methods have been developed over the years to measure lignin levels in different plant species. Most frequently used among workers involved with forage development or utilization are the acid detergent, Mason, and permanganate lignin methods. More recently, acetyl bromide has received attention as a possible lignin detn. method. The acetyl bromide method is dependent on detg. the absorbance of the ext. in which all the lignin of a sample has been dissolved. Each of these methods gives different lignin values for the same type of forage sample. For example, acid detergent, Mason, permanganate, and acetyl bromide lignin methods give quite different values for alfalfa stems: 93, 145, 158, and 135 g lignin kg-1 cell wall, resp. These differences can be even greater for grasses: 25, 77,45, and 92 g kg-1 cell wall from corn (Zea mays L.) stalks analyzed by acid detergent, Mason, permanganate, and acetyl bromide lignin methods, resp. This paper will discuss the different lignin detn. methods and highlight the advantages and disadvantages of each as they relate to forage sample anal.
- 28Moreira-Vilar, F. C.; De Cassia Siqueira-Soares, R.; Finger-Teixeira, A.; De Oliveira, D. M.; Ferro, A. P.; Da Rocha, G. J.; Maria de Lourdes, L. F.; Dos Santos, W. D.; Ferrarese-Filho, O. The Acetyl Bromide Method Is Faster, Simpler and Presents Best Recovery of Lignin in Different Herbaceous Tissues Than Klason and Thioglycolic Acid Methods. PLoS One 2014, 9 (10), e110000 DOI: 10.1371/journal.pone.0110000Google Scholar28https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvVOqtr%252FK&md5=e72ab2af2eaeeecf2d5796b0ce01b349The acetyl bromide method is faster, simpler and presents best recovery of lignin in different herbaceous tissues than Klason and thioglycolic acid methodsMoreira-Vilar, Flavia Carolina; de Cassia Siqueira-Soares, Rita; Finger-Teixeira, Aline; de Oliveira, Dyoni Matias; Ferro, Ana Paula; da Rocha, George Jackson; de Lourdes L. Ferrarese, Maria; dos Santos, Wanderley Dantas; Ferrarese-Filho, OsvaldoPLoS One (2014), 9 (10), e110000/1-e110000/7, 7 pp.CODEN: POLNCL; ISSN:1932-6203. (Public Library of Science)We compared the amt. of lignin as detd. by the three most traditional methods for lignin measurement in three tissues (sugarcane bagasse, soybean roots and soybean seed coat) contrasting for lignin amt. and compn. Although all methods presented high reproducibility, major inconsistencies among them were found. The amt. of lignin detd. by thioglycolic acid method was severely lower than that provided by the other methods (up to 95%) in all tissues analyzed. Klason method was quite similar to acetyl bromide in tissues contg. higher amts. of lignin, but presented lower recovery of lignin in the less lignified tissue. To investigate the causes of the inconsistencies obsd., we detd. the monomer compn. of all plant materials, but found no correlation. We found that the low recovery of lignin presented by the thioglycolic acid method were due losses of lignin in the residues disposed throughout the procedures. The prodn. of furfurals by acetyl bromide method does not explain the differences obsd. The acetyl bromide method is the simplest and fastest among the methods evaluated presenting similar or best recovery of lignin in all the tissues assessed.
- 29van Erven, G.; de Visser, R.; Merkx, D. W. H.; Strolenberg, W.; de Gijsel, P.; Gruppen, H.; Kabel, M. A. Quantification of Lignin and Its Structural Features in Plant Biomass Using 13C Lignin as Internal Standard for Pyrolysis-GC-SIM-MS. Anal. Chem. 2017, 89 (20), 10907– 10916, DOI: 10.1021/acs.analchem.7b02632Google Scholar29https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsFeit7nN&md5=42c592cc448c6fdde3a61f8f00c933c5Quantification of Lignin and Its Structural Features in Plant Biomass Using 13C Lignin as Internal Standard for Pyrolysis-GC-SIM-MSvan Erven, Gijs; de Visser, Ries; Merkx, Donny W. H.; Strolenberg, Willem; de Gijsel, Peter; Gruppen, Harry; Kabel, Mirjam A.Analytical Chemistry (Washington, DC, United States) (2017), 89 (20), 10907-10916CODEN: ANCHAM; ISSN:0003-2700. (American Chemical Society)Understanding the mechanisms underlying plant biomass recalcitrance at the mol. level can only be achieved by accurate analyses of both the content and structural features of the mols. involved. Current quantification of lignin is, however, mainly based on unspecific gravimetric anal. after sulfuric acid hydrolysis. Hence, the research aimed at specific lignin quantification with concurrent characterization of its structural features. Hereto, for the first time, a polymeric 13C lignin was used as internal std. (IS) for lignin quantification via anal. pyrolysis coupled to gas chromatog. with mass-spectrometric detection in selected ion monitoring mode (py-GC-SIM-MS). In addn., relative response factors (RRFs) for the various pyrolysis products obtained were detd. and applied. First, 12C and 13C lignin were isolated from nonlabeled and uniformly 13C labeled wheat straw, resp., and characterized by heteronuclear single quantum coherence (HSQC), NMR, and py-GC/MS. The two lignin isolates were found to have identical structures. Second, 13C-IS based lignin quantification by py-GC-SIM-MS was validated in reconstituted biomass model systems with known contents of the 12C lignin analog and was shown to be extremely accurate (>99.9%, R2 > 0.999) and precise (RSD < 1.5%). Third, 13C-IS based lignin quantification was applied to four common pomaceous biomass sources (wheat straw, barley straw, corn stover, and sugar cane bagasse), and lignin contents were in good agreement with the total gravimetrically detd. lignin contents. The robust method proves to be a promising alternative for the high-throughput quantification of lignin in milled biomass samples directly and simultaneously provides a direct insight into the structural features of lignin.
- 30van Erven, G.; Nayan, N.; Sonnenberg, A. S. M.; Hendriks, W. H.; Cone, J. W.; Kabel, M. A. Mechanistic Insight in the Selective Delignification of Wheat Straw by Three White-Rot Fungal Species through Quantitative 13C-IS py-GC-MS and Whole Cell Wall HSQC NMR. Biotechnol. Biofuels 2018, 11, 262, DOI: 10.1186/s13068-018-1259-9Google ScholarThere is no corresponding record for this reference.
- 31van Erven, G.; Wang, J.; Sun, P.; de Waard, P.; van der Putten, J.; Frissen, G. E.; Gosselink, R. J. A.; Zinovyev, G.; Potthast, A.; van Berkel, W. J. H.; Kabel, M. A. Structural Motifs of Wheat Straw Lignin Differ in Susceptibility to Degradation by the White-Rot Fungus Ceriporiopsis Subvermispora. ACS Sustainable Chem. Eng. 2019, 7 (24), 20032– 20042, DOI: 10.1021/acssuschemeng.9b05780Google ScholarThere is no corresponding record for this reference.
- 32Cen, E. 113–1; Durability of Wood and Wood-Based Products. Test Method against Wood Destroying Basidiomycetes. Part 1: Assessment of Biocidal Efficacy of Wood Preservatives; European Committee for Standardization: Brussels, Belgium, 2020.Google ScholarThere is no corresponding record for this reference.
- 33Cen, E. 113–2; Durability of Wood and Wood-Based Products. Test Method against Wood Destroying Basidiomycetes. Part 2: Assessment of Inherent or Enhanced Durability; European Committee for Standardization: Brussels, Belgium, 2020.Google ScholarThere is no corresponding record for this reference.
- 34AWPA Laboratory Method for Evaluating the Decay Resistance of Wood-Based Materials against Pure Basidiomycete Cultures: Soil/Block Test . Standard E10–22. AWPA Std. Methods 2022.Google ScholarThere is no corresponding record for this reference.
- 35ENV 807 Wood Preservatives–Determination of the Effectiveness against Soft Rotting Micro-Fungi and Other Soil Inhabiting Micro-Organisms; European Committee for Standardization: Brussels, Belgium, 2001.Google ScholarThere is no corresponding record for this reference.
- 36Sluiter, A.; Hames, B.; Ruiz, R.; Scarlata, C.; Sluiter, J.; Templeton, D.; Crocker, D. Determination of Structural Carbohydrates and Lignin in Biomass. Lab. Anal. Proced. 2008, 1617 (1), 1– 16Google ScholarThere is no corresponding record for this reference.
- 37Dence, C. W. The Determination of Lignin. In Methods in Lignin Chemistry, Lin, S. Y.; Dence, C. W., Eds.; Springer: Berlin Heidelberg, 1992; pp 33– 61.Google ScholarThere is no corresponding record for this reference.
- 38Jones, D. B. Factors for Converting Percentages of Nitrogen in Foods and Feeds into Percentages of Proteins; US Department of Agriculture: 1931.Google ScholarThere is no corresponding record for this reference.
- 39van Erven, G.; de Visser, R.; de Waard, P.; van Berkel, W. J. H.; Kabel, M. A. Uniformly 13C Labeled Lignin Internal Standards for Quantitative Pyrolysis-GC-MS Analysis of Grass and Wood. ACS Sustainable Chem. Eng. 2019, 7 (24), 20070– 20076, DOI: 10.1021/acssuschemeng.9b05926Google Scholar39https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXitFKqu7rL&md5=80c588a00817dbc8c9106e82816b1272Uniformly 13C Labeled Lignin Internal Standards for Quantitative Pyrolysis-GC-MS Analysis of Grass and Woodvan Erven, Gijs; de Visser, Ries; de Waard, Pieter; van Berkel, Willem J. H.; Kabel, Mirjam A.ACS Sustainable Chemistry & Engineering (2019), 7 (24), 20070-20076CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)With the ever-advancing lignocellulose valorization strategies, lignin analyses need to advance as well. However, lignin quantification still heavily relies on unspecific, time- and sample-consuming gravimetric, and spectrophotometric analyses. Here, we demonstrate that lignin isolates from uniformly 13C-labeled wheat straw, willow, and douglas fir serve as "ideal" internal stds. for pyrolysis gas chromatog. high-resoln. mass spectrometry (py-GC-HR-MS) analyses of plant biomass, allowing the accurate and precise quantification and structural characterization of lignin in grasses, hardwoods, and softwoods. The 13C lignin internal stds. were comprehensively structurally characterized by HSQC NMR and py-GC-HR-MS analyses, and their application for lignin quantification was validated in biomass model systems and in actual plant biomass. For all botanical origins and species, the lignin content was detd. within 5% relative deviation of the Klason benchmark. These results establish the capability of the developed anal. platform to selectively quantify and structurally characterize lignin simultaneously and demonstrate a valuable addn. to the lignin anal. toolbox. Uniformly 13C-labeled lignin isolates enable the concurrent quantification and structural characterization of lignin in grasses, hardwoods, and softwoods by pyrolysis gas chromatog. high-resoln. mass spectrometry.
- 40van Erven, G.; Hendrickx, P.; Al Hassan, M.; Beelen, B.; op den Kamp, R.; Keijsers, E.; van der Cruijsen, K.; Trindade, L. M.; Harmsen, P. F. H.; van Peer, A. F. Plant Genotype and Fungal Strain Harmonization Improves Miscanthus Sinensis Conversion by the White-Rot Fungus Ceriporiopsis Subvermispora. ACS Sustainable Chem. Eng. 2023, 11 (17), 6752– 6764, DOI: 10.1021/acssuschemeng.3c00815Google ScholarThere is no corresponding record for this reference.
- 41Del Río, J. C.; Rencoret, J.; Prinsen, P.; Martínez, Á. T.; Ralph, J.; Gutiérrez, A. Structural Characterization of Wheat Straw Lignin as Revealed by Analytical Pyrolysis, 2D-NMR, and Reductive Cleavage Methods. J. Agric. Food Chem. 2012, 60 (23), 5922– 5935, DOI: 10.1021/jf301002nGoogle Scholar41https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xnt1Wkt7k%253D&md5=2b9ed69b99c329c6ed8fd460820f837aStructural Characterization of Wheat Straw Lignin as Revealed by Analytical Pyrolysis, 2D-NMR, and Reductive Cleavage Methodsdel Rio, Jose C.; Rencoret, Jorge; Prinsen, Pepijn; Martinez, Angel T.; Ralph, John; Gutierrez, AnaJournal of Agricultural and Food Chemistry (2012), 60 (23), 5922-5935CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)The structure of the lignin in wheat straw has been investigated by a combination of anal. pyrolysis, 2D-NMR, and derivatization followed by reductive cleavage (DFRC). It is a p-hydroxyphenyl-guaiacyl-syringyl lignin (with an H:G:S ratio of 6:64:30) assocd. with p-coumarates and ferulates. 2D-NMR indicated that the main substructures present are β-O-4'-ethers (∼75%), followed by phenylcoumarans (∼11%), with lower amts. of other typical units. A major new finding is that the flavone tricin is apparently incorporated into the lignins. NMR and DFRC indicated that the lignin is partially acylated (∼10%) at the γ-carbon, predominantly with acetates that preferentially acylate guaiacyl (12%) rather than syringyl (1%) units; in dicots, acetylation is predominantly on syringyl units. P-Coumarate esters were barely detectable (<1%) on monomer conjugates released by selectively cleaving β-ethers in DFRC, indicating that they might be preferentially involved in condensed or terminal structures.
- 42Ralph, S. A.; Ralph, J.; Lu, F. NMR Database of Lignin and Cell Wall Model Compounds. http://www.glbrc.org/databases_and_software/nmrdatabase/. Accessed 2024–05–01.Google ScholarThere is no corresponding record for this reference.
- 43Gosselink, R. J. A.; van Dam, J. E. G.; de Jong, E.; Scott, E. L.; Sanders, J. P. M.; Li, J.; Gellerstedt, G. Fractionation, Analysis, and PCA Modeling of Properties of Four Technical Lignins for Prediction of Their Application Potential in Binders. Holzforschung 2010, 64 (2), 193– 200, DOI: 10.1515/hf.2010.023Google Scholar43https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXivFCmtbs%253D&md5=3f6312b54572e001f290b7ad8a5ae779Fractionation, analysis, and PCA modeling of properties of four technical lignins for prediction of their application potential in bindersGosselink, Richard J. A.; van Dam, Jan E. G.; de Jong, Ed; Scott, Elinor L.; Sanders, Johan P. M.; Li, Jiebing; Gellerstedt, GoeranHolzforschung (2010), 64 (2), 193-200CODEN: HOLZAZ; ISSN:0018-3830. (Walter de Gruyter GmbH & Co. KG)Functional properties of tech. lignins need to be characterized in more detail to become a higher added value renewable raw material for the chem. industry. The suitability of a lignin from different plants or trees obtained by different tech. processes can only be predicted for selected applications, such as binders, if reliable anal. data are available. In the present paper, structure dependent properties of four industrial lignins were analyzed before and after successive org. solvent extns. The lignins have been fractionated according to their molar mass by these solvents extns. Kraft and soda lignins were shown to have different molar mass distributions and chem. compns. Lignin carbohydrate complexes are most recalcitrant for extn. with org. solvents. These poorly sol. complexes can consist of up to 34% of carbohydrates in soda lignins. Modeling by principal component anal. (PCA) was performed aiming at prediction of the application potential of different lignins for binder prodn. The lignins and their fractions could be classified in different clusters based on their properties, which are structure dependent. Kraft soft-wood lignins show the highest potential for plywood binder application followed by hardwood soda lignin and the fractions of Sarkanda grass soda lignin with medium molar mass. Expectedly, the softwood lignins contain the highest no. of reactive sites in ortho positions to the phenolic OH group. Moreover, these lignins have a low level of impurities and medium molar mass.
- 44Granata, A.; Argyropoulos, D. S. 2-Chloro-4,4,5,5-Tetramethyl-1,3,2-Dioxaphospholane, a Reagent for the Accurate Determination of the Uncondensed and Condensed Phenolic Moieties in Lignins. J. Agric. Food Chem. 1995, 43 (6), 1538– 1544, DOI: 10.1021/jf00054a023Google Scholar44https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2MXlvFWrtrY%253D&md5=c70e0fa359d869c64e5500f305a68e992-Chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane, a Reagent for the Accurate Determination of the Uncondensed and Condensed Phenolic Moieties in LigninsGranata, Alessandro; Argyropoulos, Dimitris S.Journal of Agricultural and Food Chemistry (1995), 43 (6), 1538-44CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)The use of 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane as a phosphitylation reagent in quant. 31P NMR anal. of the hydroxyl groups in lignins has been thoroughly examd., and an exptl. protocol recommended for spectra acquisition has been developed. Quant. anal. of six "std. lignins" gave results comparable to those obtained by other methods of anal. Excellent resoln. of the various phenolic hydroxyl environments including those present in condensed moieties was obsd. However, this was at the expense of resoln. in the aliph. hydroxyl region, where no distinction between primary, secondary, and the erythro and threo forms of the secondary hydroxyls of the β-O-4 bonds can be made.
- 45Constant, S.; Wienk, H. L. J.; Frissen, A. E.; Peinder, P. d.; Boelens, R.; van Es, D. S.; Grisel, R. J. H.; Weckhuysen, B. M.; Huijgen, W. J. J.; Gosselink, R. J. A.; Bruijnincx, P. C. A. New Insights into the Structure and Composition of Technical Lignins: A Comparative Characterisation Study. Green Chem. 2016, 18 (9), 2651– 2665, DOI: 10.1039/C5GC03043AGoogle Scholar45https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28Xit1Oru7c%253D&md5=316cc097824f176d95a4ed876013d3efNew insights into the structure and composition of technical lignins: a comparative characterisation studyConstant, Sandra; Wienk, Hans L. J.; Frissen, Augustinus E.; de Peinder, Peter; Boelens, Rolf; van Es, Daan S.; Grisel, Ruud J. H.; Weckhuysen, Bert M.; Huijgen, Wouter J. J.; Gosselink, Richard J. A.; Bruijnincx, Pieter C. A.Green Chemistry (2016), 18 (9), 2651-2665CODEN: GRCHFJ; ISSN:1463-9262. (Royal Society of Chemistry)Detailed insight into the structure and compn. of industrial (tech.) lignins is needed to devise efficient thermal, bio- or chemocatalytic valorisation strategies. Six such tech. lignins covering three main industrial pulping methods (Indulin AT Kraft, Protobind 1000 soda lignin and Alcell, poplar, spruce and wheat straw organosolv lignins) were comprehensively characterised by lignin compn. anal., FT-IR, pyrolysis-GC-MS, quant. 31P and 2D HSQC NMR anal. and molar mass distribution by Size Exclusion Chromatog. (SEC). A comparison of nine SEC methods, including the first anal. of lignins with com. alk. SEC columns, showed molar masses to vary considerably, allowing some recommendations to be made. The lignin molar mass decreased in the order: Indulin Kraft > soda P1000 > Alcell > OS-W ∼ OS-P ∼ OS-S, regardless of the SEC method chosen. Structural identification and quantification of arom. units and inter-unit linkages indicated that all tech. lignins, including the organosolv ones, have considerably been degraded and condensed by the pulping process. Importantly, low amts. of β- ether linkages were found compared to literature values for protolignin and lignins obtained by other, milder isolation processes. Stilbenes and ether furfural units could also be identified in some of the lignins. Taken together, the insights gained in the structure of the tech. lignins, in particular, the low β-O-4 contents, carry implications for the design of lignin valorisation strategies including (catalytic) depolymn. and material applications.
- 46Rumpf, J.; Burger, R.; Schulze, M. Statistical evaluation of DPPH, ABTS, FRAP, and Folin-Ciocalteu assays to assess the antioxidant capacity of lignins. Int. J. Biol. Macromol. 2023, 233, 123470 DOI: 10.1016/j.ijbiomac.2023.123470Google Scholar46https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXis1yltrk%253D&md5=4a7a6c4ce3d4a1dee474a02f43e4e042Statistical evaluation of DPPH, ABTS, FRAP, and Folin-Ciocalteu assays to assess the antioxidant capacity of ligninsRumpf, Jessica; Burger, Rene; Schulze, MargitInternational Journal of Biological Macromolecules (2023), 233 (), 123470CODEN: IJBMDR; ISSN:0141-8130. (Elsevier B.V.)This research studies in detail four different assays, namely DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), FRAP (ferric ion reducing antioxidant potential) and FC (Folin-Ciocalteu), to det. the antioxidant capacity of std. substances as well as 50 organosolv lignins, and two kraft lignins. The coeff. of variation was detd. for each method and was lowest for ABTS and highest for DPPH. The best correlation was found for FRAP and FC, which both rely on a single electron transfer mechanism. A good correlation between ABTS, FRAP and FC, resp., could be obsd., even though ABTS relies on a more complex reaction mechanism. The DPPH assay merely correlates with the others, implying that it reflects different antioxidative attributes due to a different reaction mechanism. Lignins obtained from paulownia and silphium have been investigated for the first time regarding their antioxidant capacity. Paulownia lignin is in the same range as beech wood lignin, while silphium lignin resembles wheat straw lignin. Miscanthus lignin is an exception from the grass lignins and possesses a significantly higher antioxidant capacity. All lignins possess a good antioxidant capacity and thus are promising candidates for various applications, e. g. as additives in food packaging or for biomedical purposes.
- 47Arantes, V.; Goodell, B. Current Understanding of Brown-Rot Fungal Biodegradation Mechanisms: A Review. In Deterioration and Protection of Sustainable Biomaterials, ACS Symposium Series, American Chemical Society: 2014; Vol. 1158, pp 3– 21.Google ScholarThere is no corresponding record for this reference.
- 48Zhang, J.; Silverstein, K. A. T.; Castaño, J. D.; Figueroa, M.; Schilling, J. S. Gene Regulation Shifts Shed Light on Fungal Adaption in Plant Biomass Decomposers. mBio 2019, 10 (6), e02176-19 DOI: 10.1128/mBio.02176-19Google ScholarThere is no corresponding record for this reference.
- 49Duran, K.; Kohlstedt, M.; van Erven, G.; Klostermann, C. E.; America, A. H. P.; Bakx, E.; Baars, J. J. P.; Gorissen, A.; de Visser, R.; de Vries, R. P.; Wittmann, C.; Comans, R. N. J.; Kuyper, T. W.; Kabel, M. A. From 13C-Lignin to 13C-Mycelium: Agaricus Bisporus Uses Polymeric Lignin as a Carbon Source. Sci. Adv. 2024, 10 (16), eadl3419 DOI: 10.1126/sciadv.adl3419Google ScholarThere is no corresponding record for this reference.
- 50Duran, K.; Miebach, J.; van Erven, G.; Baars, J. J. P.; Comans, R. N. J.; Kuyper, T. W.; Kabel, M. A. Oxidation-Driven Lignin Removal by Agaricus Bisporus from Wheat Straw-Based Compost at Industrial Scale. Int. J. Biol. Macromol. 2023, 246, 125575 DOI: 10.1016/j.ijbiomac.2023.125575Google ScholarThere is no corresponding record for this reference.
- 51van Kuijk, S. J. A.; Sonnenberg, A. S. M.; Baars, J. J. P.; Hendriks, W. H.; del Río, J. C.; Rencoret, J.; Gutiérrez, A.; de Ruijter, N. C. A.; Cone, J. W. Chemical Changes and Increased Degradability of Wheat Straw and Oak Wood Chips Treated with the White Rot Fungi Ceriporiopsis Subvermispora and Lentinula Edodes. Biomass Bioenergy 2017, 105, 381– 391, DOI: 10.1016/j.biombioe.2017.07.003Google Scholar51https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhtlCqtLbP&md5=5a99151c39c6085b6f0bd3f755a08bcfChemical changes and increased degradability of wheat straw and oak wood chips treated with the white rot fungi Ceriporiopsis subvermispora and Lentinula edodesvan Kuijk, Sandra J. A.; Sonnenberg, Anton S. M.; Baars, Johan J. P.; Hendriks, Wouter H.; del Rio, Jose C.; Rencoret, Jorge; Gutierrez, Ana; de Ruijter, Norbert C. A.; Cone, John W.Biomass and Bioenergy (2017), 105 (), 381-391CODEN: BMSBEO; ISSN:0961-9534. (Elsevier Ltd.)Wheat straw and oak wood chips were incubated with Ceriporiopsis subvermispora and Lentinula edodes for 8 wk. Samples from the fungal treated substrates were collected every week for chem. characterization. L. edodes continuously grew during the 8 wk on both wheat straw and oak wood chips, as detd. by the ergosterol mass fraction of the dry biomass. C. subvermispora colonized both substrates during the first week, stopped growing on oak wood chips, and resumed growth after 6 wk on wheat straw. Detergent fiber anal. and pyrolysis coupled to gas chromatog./mass spectrometry showed a selective lignin degrdn. in wheat straw, although some carbohydrates were also degraded. L. edodes continuously degraded lignin and hemicelluloses in wheat straw while C. subvermispora degraded lignin and hemicelluloses only during the first 5 wk of treatment after which cellulose degrdn. started. Both fungi selectively degraded lignin in wood chips. After 4 wk of treatment, no significant changes in chem. compn. were detected. In contrast to L. edodes, C. subvermispora produced alkylitaconic acids during fungal treatment, which paralleled the degrdn. and modification of lignin indicating the importance of these compds. in delignification. Light microscopy visualized a dense structure of wood chips which was difficult to penetrate by the fungi, explaining the relative lower lignin degrdn. compared to wheat straw measured by chem. anal. All these changes resulted in an increased in in vitro rumen degradability of wheat straw and oak wood chips. In addn., more glucose and xylose were released after enzymic saccharification of fungal treated wheat straw compared to untreated material.
- 52Chen, F.; Tobimatsu, Y.; Havkin-Frenkel, D.; Dixon, R. A.; Ralph, J. A Polymer of Caffeyl Alcohol in Plant Seeds. Proc. Natl. Acad. Sci. U. S. A. 2012, 109 (5), 1772– 1777, DOI: 10.1073/pnas.1120992109Google Scholar52https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XitlKltL8%253D&md5=25b17753f76803139c45bbba98ff8623A polymer of caffeyl alcohol in plant seedsChen, Fang; Tobimatsu, Yuki; Havkin-Frenkel, Daphna; Dixon, Richard A.; Ralph, JohnProceedings of the National Academy of Sciences of the United States of America (2012), 109 (5), 1772-1777, S1772/1-S1772/9CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)Lignins are complex phenylpropanoid polymers mostly assocd. with plant secondary cell walls. Lignins arise primarily via oxidative polymn. of the three monolignols, p-coumaryl, coniferyl, and sinapyl alcs. Of the two hydroxycinnamyl alcs. that represent incompletely methylated biosynthetic products (and are not usually considered to be monolignols), 5-hydroxyconiferyl alc. is now well established as incorporating into angiosperm lignins, but incorporation of caffeyl alc. has not been shown. We report here the presence of a homopolymer of caffeyl alc. in the seed coats of both monocot and dicot plants. This polymer (C-lignin) is deposited to high concns. in the seed coat during the early stages of seed development in the vanilla orchid (Vanilla planifolia), and in several members of the Cactaceae. The lignin in other parts of the Vanilla plant is conventionally biosynthesized from coniferyl and sinapyl alcs. Some species of cacti contain only C-lignin in their seeds, whereas others contain only classical guaiacyl/syringyl lignin (derived from coniferyl and sinapyl alcs.). NMR spectroscopic anal. revealed that the Vanilla seed-coat polymer was massively comprised of benzodioxane units and was structurally similar to the polymer synthesized in vitro by peroxidase-catalyzed polymn. of caffeyl alc. CD spectroscopy did not detect any optical activity in the seed polymer. These data support the contention that the C-lignin polymer is produced in vivo via combinatorial oxidative radical coupling that is under simple chem. control, a mechanism analogous to that theorized for classical lignin biosynthesis.
- 53Tobimatsu, Y.; Chen, F.; Nakashima, J.; Escamilla-Treviño, L. L.; Jackson, L.; Dixon, R. A.; Ralph, J. Coexistence but Independent Biosynthesis of Catechyl and Guaiacyl/Syringyl Lignin Polymers in Seed Coats. Plant Cell 2013, 25 (7), 2587– 2600, DOI: 10.1105/tpc.113.113142Google Scholar53https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsVKksbrO&md5=5447c49874ad69816cddd84ecef91cc8Coexistence but independent biosynthesis of catechyl and guaiacyl/syringyl lignin polymers in seed coatsTobimatsu, Yuki; Chen, Fang; Nakashima, Jin; Escamilla-Trevino, Luis L.; Jackson, Lisa; Dixon, Richard A.; Ralph, JohnPlant Cell (2013), 25 (7), 2587-2600CODEN: PLCEEW; ISSN:1040-4651. (American Society of Plant Biologists)Lignins are phenylpropanoid polymers, derived from monolignols, commonly found in terrestrial plant secondary cell walls. We recently reported evidence of an unanticipated catechyl lignin homopolymer (C lignin) derived solely from caffeyl alc. in the seed coats of several monocot and dicot plants. We previously identified plant seeds that possessed either C lignin or traditional guaiacyl/syringyl (G/S) lignins, but not both. Here, we identified several dicot plants (Euphorbiaceae and Cleomaceae) that produce C lignin together with traditional G/S lignins in their seed coats. Soln.-state NMR analyses, along with an in vitro lignin polymn. study, detd. that there is, however, no copolymn. detectable (i.e., that the synthesis and polymn. of caffeyl alc. and conventional monolignols in vivo is spatially and/or temporally sepd.). In particular, the deposition of G and C lignins in Cleome hassleriana seed coats is developmentally regulated during seed maturation; C lignin appears successively after G lignin within the same testa layers, concurrently with apparent loss of the functionality of O-methyltransferases, which are key enzymes for the conversion of C to G lignin precursors. This study exemplifies the flexible biosynthesis of different types of lignin polymers in plants dictated by substantial, but poorly understood, control of monomer supply by the cells.
- 54Meng, X.; Crestini, C.; Ben, H.; Hao, N.; Pu, Y.; Ragauskas, A. J.; Argyropoulos, D. S. Determination of Hydroxyl Groups in Biorefinery Resources Via Quantitative 31P NMR Spectroscopy. Nat. Protoc. 2019, 14 (9), 2627– 2647, DOI: 10.1038/s41596-019-0191-1Google Scholar54https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhsFertb3F&md5=1e3de893abc1e41a40406d8a7d3a23f8Determination of hydroxyl groups in biorefinery resources via quantitative 31P NMR spectroscopyMeng, Xianzhi; Crestini, Claudia; Ben, Haoxi; Hao, Naijia; Pu, Yunqiao; Ragauskas, Arthur J.; Argyropoulos, Dimitris S.Nature Protocols (2019), 14 (9), 2627-2647CODEN: NPARDW; ISSN:1750-2799. (Nature Research)The anal. of chem. structural characteristics of biorefinery product streams (such as lignin and tannin) has advanced substantially over the past decade, with traditional wet-chem. techniques being replaced or supplemented by NMR methodologies. Quant. 31P NMR spectroscopy is a promising technique for the anal. of hydroxyl groups because of its unique characterization capability and broad potential applicability across the biorefinery research community. This protocol describes procedures for (i) the prepn./solubilization of lignin and tannin, (ii) the phosphitylation of their hydroxyl groups, (iii) NMR acquisition details, and (iv) the ensuing data analyses and means to precisely calc. the content of the different types of hydroxyl groups. Compared with traditional wet-chem. techniques, the technique of quant. 31P NMR spectroscopy offers unique advantages in measuring hydroxyl groups in a single spectrum with high signal resoln. The method provides complete quant. information about the hydroxyl groups with small amts. of sample (~ 30 mg) within a relatively short exptl. time (~ 30-120 min).
- 55Kirk, T. K.; Tien, M.; Kersten, P. J.; Mozuch, M. D.; Kalyanaraman, B. Ligninase of Phanerochaete Chrysosporium. Mechanism of Its Degradation of the Non-Phenolic Arylglycerol β-Aryl Ether Substructure of Lignin. Biochem. J. 1986, 236 (1), 279– 287, DOI: 10.1042/bj2360279Google ScholarThere is no corresponding record for this reference.
- 56Wu, X.; Smet, E.; Brandi, F.; Raikwar, D.; Zhang, Z.; Maes, B. U. W.; Sels, B. F. Advancements and Perspectives toward Lignin Valorization Via O-Demethylation. Angew. Chem., Int. Ed. 2024, 63 (10), e202317257 DOI: 10.1002/anie.202317257Google ScholarThere is no corresponding record for this reference.
- 57Golten, O.; Ayuso-Fernández, I.; Hall, K. R.; Stepnov, A. A.; Sørlie, M.; Røhr, Å. K.; Eijsink, V. G. H. Reductants Fuel Lytic Polysaccharide Monooxygenase Activity in a pH-dependent Manner. FEBS Lett. 2023, 597 (10), 1363– 1374, DOI: 10.1002/1873-3468.14629Google Scholar57https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXpsFGjurg%253D&md5=cdd019aad10a9a69041caa3dc3ec1223Reductants fuel lytic polysaccharide monooxygenase activity in a pH-dependent mannerGolten, Ole; Ayuso-Fernandez, Ivan; Hall, Kelsi R.; Stepnov, Anton A.; Soerlie, Morten; Roehr, Ssmund Kjendseth; Eijsink, Vincent G. H.FEBS Letters (2023), 597 (10), 1363-1374CODEN: FEBLAL; ISSN:0014-5793. (Wiley-Blackwell)Polysaccharide-degrading mono-copper lytic polysaccharide monooxygenases (LPMOs) are efficient peroxygenases that require electron donors (reductants) to remain in the active Cu(I) form and to generate the H2O2 co-substrate from mol. oxygen. Here, we show how commonly used reductants affect LPMO catalysis in a pH-dependent manner. Between pH 6.0 and 8.0, reactions with ascorbic acid show little pH dependency, whereas reactions with gallic acid become much faster at increased pH. These dependencies correlate with the reductant ionization state, which affects its ability to react with mol. oxygen and generate H2O2. The correlation does not apply to L-cysteine because, as shown by stopped-flow kinetics, increased H2O2 prodn. at higher pH is counteracted by increased binding of L-cysteine to the copper active site. The findings highlight the importance of the choice of reductant and pH in LPMO reactions.
- 58Kommedal, E. G.; Angeltveit, C. F.; Klau, L. J.; Ayuso-Fernández, I.; Arstad, B.; Antonsen, S. G.; Stenstrøm, Y.; Ekeberg, D.; Gírio, F.; Carvalheiro, F.; Horn, S. J.; Aachmann, F. L.; Eijsink, V. G. H. Visible Light-Exposed Lignin Facilitates Cellulose Solubilization by Lytic Polysaccharide Monooxygenases. Nat. Commun. 2023, 14 (1), 1063, DOI: 10.1038/s41467-023-36660-4Google ScholarThere is no corresponding record for this reference.
- 59Lu, X.; Gu, X.; Shi, Y. A Review on Lignin Antioxidants: Their Sources, Isolations, Antioxidant Activities and Various Applications. Int. J. Biol. Macromol. 2022, 210, 716– 741, DOI: 10.1016/j.ijbiomac.2022.04.228Google Scholar59https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xht1ant7fO&md5=839448455c38736db7a482f1d5feb23aA review on lignin antioxidants: Their sources, isolations, antioxidant activities and various applicationsLu, Xinyu; Gu, Xiaoli; Shi, YijunInternational Journal of Biological Macromolecules (2022), 210 (), 716-741CODEN: IJBMDR; ISSN:0141-8130. (Elsevier B.V.)A review. Lignin, a biopolymer obtained from agricultural/forestry residues or paper pulping wastewater, is rich in arom. structure, which is central to its adoption as a candidate to natural antioxidants. Through insight into its structural features from biomass, different functional groups would influence lignin antioxidant activity, wherein phenolic content is the most important factor, hence massive studies have focused on its improvement via different pretreatments and post-processing methods. Besides, lignin nanoparticles and chem. modifications are also efficient methods to improve antioxidant activity via increasing free content and decreasing bond dissocn. enthalpy of phenolic hydroxyl. Lignin samples exhibit comparable radicals scavenging ability to com. ones, showing their potential as renewable alternatives of synthesized antioxidants. Besides, their applications have also been discussed, which demonstrates lignin potential as an inexpensive antioxidant additive and consequent improvements on multiple functionalities. This review is dedicated to summarize lignin antioxidants extd. from biomass resources, methods to improve their antioxidant activity and their applications, which is beneficial for realizing lignin valorization.
- 60Gao, Z.; Lang, X.; Chen, S.; Zhao, C. Mini-Review on the Synthesis of Lignin-Based Phenolic Resin. Energy Fuels 2021, 35 (22), 18385– 18395, DOI: 10.1021/acs.energyfuels.1c03177Google Scholar60https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXisVagsr%252FJ&md5=c02ad6a5a8739c0c973b649c974d41c0Mini-Review on the Synthesis of Lignin-Based Phenolic ResinGao, Zhiwen; Lang, Xueling; Chen, Shuang; Zhao, ChenEnergy & Fuels (2021), 35 (22), 18385-18395CODEN: ENFUEM; ISSN:0887-0624. (American Chemical Society)A review. The use of biomass in phenolic resin can not only improve performance and reduce costs but can also reduce pollution and protect the environment. Lignin is a biopolymer with a three-dimensional network structure formed by three phenylpropane units of p-hydroxyphenyl, guaiacyl, and syringyl connected by an ether bond and carbon-carbon bond, contg. a large amt. of phenol or an aldehyde structure unit. It is an effective way to improve the economy, protect the environment, and reproduce the resin via the synthesis of high-performance biophenolic resin polymer materials by modification or depolymn. of lignin. This review describes the latest developments in the prepn. of phenolic resins by modification or depolymn. of lignin, focusing on the modification of its original functional groups by phenolization, demethylation, and hydroxymethylation, as well as chem. depolymn. methods. The properties of thermosetting or thermoplastic phenolic resins as prepd. by different lignin modification methods are compared, and the future research directions for the synthesis of biomass-based phenolic resins are prospected.
- 61Giummarella, N.; Lindén, P. A.; Areskogh, D.; Lawoko, M. Fractional Profiling of Kraft Lignin Structure: Unravelling Insights on Lignin Reaction Mechanisms. ACS Sustainable Chem. Eng. 2020, 8 (2), 1112– 1120, DOI: 10.1021/acssuschemeng.9b06027Google Scholar61https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXitl2lsr%252FL&md5=f69fc7cfba09bed2edb5a0c5f044a1d9Fractional Profiling of Kraft Lignin Structure: Unravelling Insights on Lignin Reaction MechanismsGiummarella, Nicola; Linden, Paer A.; Areskogh, Dimitri; Lawoko, MartinACS Sustainable Chemistry & Engineering (2020), 8 (2), 1112-1120CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)The kraft process is the main process used for the prodn. of chem. pulps. In this process, an efficient delignification is achieved, yielding bleachable grade pulps. In recent years, there has been interest in valorization of the dissolved lignins, prompted by the development of tech. feasible processes to retrieve it from the black liquor. However, the structural-, functional-, and size-related heterogeneities of lignin present both anal. challenges and challenges in developing new applications. Hence, refining of the crude product is essential. Herein, advanced NMR characterization (13C NMR, APT/DEPT NMR, 31P NMR, HSQC, HMBC, HSQC-TOCSY) was applied to profile the detailed mol. structures of refined kraft lignins and unravel mechanistic insights on important lignin reactions during kraft pulping. From this structural anal. of the lignins, a model oligomer was synthesized and analyzed to provide support to the effect that a retro-aldol reaction in combination with radical recombination reactions play a significant role in the formation of the reconstituted fraction of kraft lignin. In this regard, a new type of linkage accounting for approx. 10% of the interunits in kraft lignin is reported. Mol. structural studies corroborate that retro-aldol reaction followed by radical recombination is a crucial mechanism of lignin condensation during kraft pulping.
- 62Giummarella, N.; Pylypchuk, I. V.; Sevastyanova, O.; Lawoko, M. New Structures in Eucalyptus Kraft Lignin with Complex Mechanistic Implications. ACS Sustainable Chem. Eng. 2020, 8 (29), 10983– 10994, DOI: 10.1021/acssuschemeng.0c03776Google Scholar62https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXht1OhurjF&md5=e9ab3bc2f312cd632afdd7944d180456New Structures in Eucalyptus Kraft Lignin with Complex Mechanistic ImplicationsGiummarella, Nicola; Pylypchuk, Ievgen V.; Sevastyanova, Olena; Lawoko, MartinACS Sustainable Chemistry & Engineering (2020), 8 (29), 10983-10994CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)Recent years have seen the development of tech. feasible methods to retrieve kraft lignin from the black liquor as solids or liqs. This opens enormous opportunities to position kraft lignin as a renewable arom. polymer precursor. However, the heterogeneity of kraft lignin is one major hurdle and manifests in its largely unknown mol. structure, which in recent years has drawn further attention. In this context, we herein studied the detailed structure of Eucalyptus kraft lignin with special emphasis on identifying new linkages signatory to retro-aldol and subsequent radical coupling reactions, which we recently showed to be a key reaction sequence contributing to the structure of spruce kraft lignin. In combination with novel model studies, we unequivocally identified new structures by advanced 2D NMR characterization of Eucalyptus kraft lignin, i.e., 3,5-tetramethoxy-para-diphenol, 3-dimethoxy-para-diphenol and small amts. of 3,5-dimethoxy-benzoquinone. These structures are signatory to retro-aldol followed by radical coupling reactions. The two diphenol structures were further quantified by 1D 13C NMR at 9% of the interunit linkages in Eucalyptus kraft lignin, which was comparable to the amts. we previously identified in softwood kraft lignin (10%). Radical condensation of kraft lignin to form carbon-carbon bonds therefore does not discriminate between syringyl lignin and guaiacyl lignin units. We rationalize such indiscrimination to emanate from possibilities for radical couplings at unsubstituted C1 in the formed syringol and guaiacol lignin as a result of the retro-aldol reaction. Radical condensation of kraft lignin to form carbon-carbon bonds does not discriminate between syringyl lignin and guaiacyl lignin units.
- 63van Erven, G.; Boerkamp, V. J. P.; van Groenestijn, J. W.; Gosselink, R. J. A. Choline and Lactic Acid Covalently Incorporate into the Lignin Structure during Deep Eutectic Solvent Pulping. Green Chem. 2024, 26 (12), 7101– 7112, DOI: 10.1039/D4GC00909FGoogle ScholarThere is no corresponding record for this reference.
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Abstract
Figure 1
Figure 1. Compositional analysis of spruce and birch. (A) The content of protein, acid soluble lignin (ASL), acid insoluble lignin (AIL), and carbohydrates in spruce and birch, as percentage of the total mass, determined before and after 18 weeks of brown-rot (BR) decay. (B) Removal of carbohydrates and lignin from spruce and birch after brown-rot decay, calculated based on contents analyzed (w/w%; Table S3) combined with the total gravimetric dry mass removal. Lignin was quantified with gravimetric Klason methodology (Lignin - Klason; sum of ASL and AIL) and 13C-IS pyrolysis-GC-MS (Lignin - py-GC-MS). Error bars represent standard deviation (n = 3).
Figure 2
Figure 2. HSQC NMR spectra of lignin isolates of sound and brown-rot decayed wood. The spectra show the aliphatic (A) and aromatic (B) regions for lignin isolated (through enzymatic treatment) from sound and brown-rot decayed spruce and birch. Subscripted numbers and Greek letters in annotations indicate which carbon in the annotated substructure the signal originates from. (C) Annotated substructures, where colors correspond to colored signals in A and B. Dashed lines indicate -H (guaiacyl) or -OCH3(syringyl), while the main position for further coupling is indicated with wavy lines. Unassigned peaks are shown in gray.
Figure 3
Figure 3. HSQC NMR spectra of acetylated lignin isolates of brown-rot decayed wood. The spectra show the aliphatic and aromatic regions for acetylated, brown-rot decayed spruce (A) and birch (B). Subscripted numbers and Greek letters in annotations indicate which carbon in the annotated substructure the signal originates from. Inset values present lignin component ratios determined from contour volume integrals (top: per 100 aromatic rings, bottom: relative). (C) Annotated substructures, where colors correspond to colored signals in the spectra. Dashed lines indicate -H (guaiacyl) or -OCH3 (syringyl), while the main position for further coupling is indicated with wavy lines. Unassigned peaks are shown in gray.
References
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- 1Bomble, Y. J.; Lin, C. Y.; Amore, A.; Wei, H.; Holwerda, E. K.; Ciesielski, P. N.; Donohoe, B. S.; Decker, S. R.; Lynd, L. R.; Himmel, M. E. Lignocellulose Deconstruction in the Biosphere. Curr. Opin. Chem. Biol. 2017, 41, 61– 70, DOI: 10.1016/j.cbpa.2017.10.0131https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhslOnsbvP&md5=a538b5667029ffc18098601c48a681b2Lignocellulose deconstruction in the biosphereBomble, Yannick J.; Lin, Chien-Yuan; Amore, Antonella; Wei, Hui; Holwerda, Evert K.; Ciesielski, Peter N.; Donohoe, Bryon S.; Decker, Stephen R.; Lynd, Lee R.; Himmel, Michael E.Current Opinion in Chemical Biology (2017), 41 (), 61-70CODEN: COCBF4; ISSN:1367-5931. (Elsevier B.V.)Microorganisms have evolved different and yet complementary mechanisms to degrade biomass in the biosphere. The chem. biol. of lignocellulose deconstruction is a complex and intricate process that appears to vary in response to specific ecosystems. These microorganisms rely on simple to complex arrangements of glycoside hydrolases to conduct most of these polysaccharide depolymn. reactions and also, as discovered more recently, oxidative mechanisms via lytic polysaccharide monooxygenases or non-enzymic Fenton reactions which are used to enhance deconstruction. It is now clear that these deconstruction mechanisms are often more efficient in the presence of the microorganisms. In general, a major fraction of the total plant biomass deconstruction in the biosphere results from the action of various microorganisms, primarily aerobic bacteria and fungi, as well as a variety of anaerobic bacteria. Beyond carbon recycling, specialized microorganisms interact with plants to manage nitrogen in the biosphere. Understanding the interplay between these organisms within or across ecosystems is crucial to further our grasp of chem. recycling in the biosphere and also enables optimization of the burgeoning plant-based bioeconomy.
- 2Embacher, J.; Zeilinger, S.; Kirchmair, M.; Rodriguez-r, L. M.; Neuhauser, S. Wood Decay Fungi and Their Bacterial Interaction Partners in the Built Environment - A Systematic Review on Fungal Bacteria Interactions in Dead Wood and Timber. Fungal Biol. Rev. 2023, 45, 100305 DOI: 10.1016/j.fbr.2022.100305There is no corresponding record for this reference.
- 3Ebringerová, A.; Hromádková, Z.; Heinze, T. Hemicellulose. In Polysaccharides I: Structure, Characterization and Use, Heinze, T., Ed.; Springer: Berlin Heidelberg, 2005; pp 1– 67.There is no corresponding record for this reference.
- 4Gírio, F. M.; Fonseca, C.; Carvalheiro, F.; Duarte, L. C.; Marques, S.; Bogel-Łukasik, R. Hemicelluloses for Fuel Ethanol: A Review. Bioresour. Technol. 2010, 101 (13), 4775– 4800, DOI: 10.1016/j.biortech.2010.01.0884https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXjvFynsLY%253D&md5=2d512ec11cf7fee136b7b8e9f82398d9Hemicelluloses for fuel ethanol: A reviewGirio, F. M.; Fonseca, C.; Carvalheiro, F.; Duarte, L. C.; Marques, S.; Bogel-Lukasik, R.Bioresource Technology (2010), 101 (13), 4775-4800CODEN: BIRTEB; ISSN:0960-8524. (Elsevier Ltd.)A review. Hemicellulose currently represent the largest polysaccharide fraction wasted in most cellulosic EtOH pilot and demonstration plants around the world. The reasons are based on the hemicellulose heterogeneous polymeric nature and their low fermentability by the most common industrial microbial strains. This paper will review, in a from field to fuel approach the various hemicellulose structures present in lignocellulose, the range of pre-treatment and hydrolysis options including the enzymic ones, and the role of different microbial strains on process integration aiming to reach a meaningful consolidated bio-processing. The recent trends, tech. barriers and perspectives of future development are highlighted.
- 5Scheller, H. V.; Ulvskov, P. Hemicelluloses. Annu. Rev. Plant Biol. 2010, 61, 263– 289, DOI: 10.1146/annurev-arplant-042809-1123155https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXnslSjsLw%253D&md5=860a08472e14f548d7a98f6073602b6bHemicellulosesScheller, Henrik Vibe; Ulvskov, PeterAnnual Review of Plant Biology (2010), 61 (), 263-289CODEN: ARPBDW; ISSN:1543-5008. (Annual Reviews Inc.)A review. Hemicelluloses are polysaccharides in plant cell walls that have β-(1→4)-linked backbones with an equatorial configuration. Hemicelluloses include xyloglucans, xylans, mannans and glucomannans, and β-(1→3,1→4)-glucans. These types of hemicelluloses are present in the cell walls of all terrestrial plants, except for β-(1→3,1→4)-glucans, which are restricted to Poales and a few other groups. The detailed structure of the hemicelluloses and their abundance vary widely between different species and cell types. The most important biol. role of hemicelluloses is their contribution to strengthening the cell wall by interaction with cellulose and, in some walls, with lignin. These features are discussed in relation to widely accepted models of the primary wall. Hemicelluloses are synthesized by glycosyltransferases located in the Golgi membranes. Many glycosyltransferases needed for biosynthesis of xyloglucans and mannans are known. In contrast, the biosynthesis of xylans and β-(1→3,1→4)-glucans remains very elusive, and recent studies have led to more questions than answers.
- 6Boerjan, W.; Ralph, J.; Baucher, M. Lignin Biosynthesis. Annu. Rev. Plant Biol. 2003, 54, 519– 546, DOI: 10.1146/annurev.arplant.54.031902.1349386https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXntFSnsrg%253D&md5=105230aaf27455cd3815b5aa739ced0eLignin biosynthesisBoerjan, Wout; Ralph, John; Baucher, MarieAnnual Review of Plant Biology (2003), 54 (), 519-546CODEN: ARPBDW ISSN:. (Annual Reviews Inc.)A review. The lignin biosynthetic pathway has been studied for more than a century but has undergone major revisions over the past decade. Significant progress has been made in cloning new genes by genetic and combined bioinformatics and biochem. approaches. In vitro enzymic assays and detailed analyses of mutants and transgenic plants altered in the expression of lignin biosynthesis genes have provided a solid basis for redrawing the monolignol biosynthetic pathway, and structural analyses have shown that plant cell walls can tolerate large variations in lignin content and structure. In some cases, the potential value for agriculture of transgenic plants with modified lignin structure has been demonstrated. This review presents a current picture of monolignol biosynthesis, polymn., and lignin structure.
- 7Ralph, J.; Lapierre, C.; Boerjan, W. Lignin Structure and Its Engineering. Curr. Opin. Biotechnol. 2019, 56, 240– 249, DOI: 10.1016/j.copbio.2019.02.0197https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXltVSgsbs%253D&md5=dfcdf809d89900549516292ca6b4b2dfLignin structure and its engineeringRalph, John; Lapierre, Catherine; Boerjan, WoutCurrent Opinion in Biotechnology (2019), 56 (), 240-249CODEN: CUOBE3; ISSN:0958-1669. (Elsevier B.V.)Studies on lignin structure and its engineering are inextricably and bidirectionally linked. Perturbations of genes on the lignin biosynthetic pathway may result in striking compositional and structural changes that in turn suggest novel approaches for altering lignin and even 'designing' the polymer to enhance its value or with a view toward its simpler removal from the cell wall polysaccharides. Basic structural studies on various native lignins increasingly refine our knowledge of lignin structure, and examg. lignins in different species reveals the extent to which evolution and natural variation have resulted in the incorporation of 'non-traditional' phenolic monomers, including phenolics from beyond the monolignol biosynthetic pathway. As a result, the very definition of lignin continues to be expanded and refined.
- 8Janusz, G.; Pawlik, A.; Sulej, J.; Świderska-Burek, U.; Jarosz-Wilkołazka, A.; Paszczyński, A. Lignin Degradation: Microorganisms, Enzymes Involved, Genomes Analysis and Evolution. FEMS Microbiol. Rev. 2017, 41 (6), 941– 962, DOI: 10.1093/femsre/fux0498https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhvFWmtL7M&md5=1e6608d17e8c075b01484b58b5358967Lignin degradation: Microorganisms, enzymes involved, genomes analysis and evolutionJanusz, Grzegorz; Pawlik, Anna; Sulej, Justyna; swiderska-Burek, Urszula; Jarosz-Wilkolazka, Anna; Paszczynski, AndrzejFEMS Microbiology Reviews (2017), 41 (6), 941-962CODEN: FMREE4; ISSN:1574-6976. (Oxford University Press)A review. Extensive research efforts have been dedicated to describing degrdn. of wood, which is a complex process; hence, microorganisms have evolved different enzymic and non-enzymic strategies to utilize this plentiful plant material. This review describes a no. of fungal and bacterial organisms which have developed both competitive and mutualistic strategies for the decompn. of wood and to thrive in different ecol. niches. Through the anal. of the enzymic machinery engaged in wood degrdn., it was possible to elucidate different strategies of wood decompn. which often depend on ecol. niches inhabited by given organism. Moreover, a detailed description of low mol. wt. compds. is presented, which gives these organisms not only an advantage in wood degrdn. processes, but seems rather to be a new evolutionatory alternative to enzymic combustion. Through anal. of genomics and secretomic data, it was possible to underline the probable importance of certain wood-degrading enzymes produced by different fungal organisms, potentially giving them advantage in their ecol. niches. The paper highlights different fungal strategies of wood degrdn., which possibly correlates to the no. of genes coding for secretory enzymes. Furthermore, investigation of the evolution of wood-degrading organisms has been described.
- 9Eriksson, K.-E. L.; Blanchette, R. A.; Ander, P. Morphological Aspects of Wood Degradation by Fungi and Bacteria. In Microbial and Enzymatic Degradation of Wood and Wood Components; Springer: Berlin Heidelberg, 1990; pp 1– 87.There is no corresponding record for this reference.
- 10Dashtban, M.; Schraft, H.; Syed, T. A.; Qin, W. Fungal Biodegradation and Enzymatic Modification of Lignin. Int. J. Biochem. Mol. Biol. 2010, 1 (1), 36– 5010https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXitlOrurs%253D&md5=e29660b235d6306ce814933a9fbc6fc1Fungal biodegradation and enzymatic modification of ligninDashtban, Mehdi; Schraft, Heidi; Syed, Tarannum A.; Qin, WenshengInternational Journal of Biochemistry and Molecular Biology (2010), 1 (1), 36-50CODEN: IJBMHV; ISSN:2152-4114. (e-Century Publishing Corp.)A review. Lignin, the most abundant arom. biopolymer on Earth, is extremely recalcitrant to degrdn. By linking to both hemicellulose and cellulose, it creates a barrier to any solns. or enzymes and prevents the penetration of lignocellulolytic enzymes into the interior lignocellulosic structure. Some basidiomycetes white-rot fungi are able to degrade lignin efficiently using a combination of extracellular ligninolytic enzymes, org. acids, mediators and accessory enzymes. This review describes ligninolytic enzyme families produced by these fungi that are involved in wood decay processes, their mol. structures, biochem. properties and the mechanisms of action which render them attractive candidates in biotechnol. applications. These enzymes include phenol oxidase (laccase) and heme peroxidases [lignin peroxidase (LiP), manganese peroxidase (MnP) and versatile peroxidase (VP)]. Accessory enzymes such as H2O2-generating oxidases and degrdn. mechanisms of plant cell-wall components in a non-enzymic manner by prodn. of free hydroxyl radicals (·OH) are also discussed.
- 11Martínez, A. T. Molecular Biology and Structure-Function of Lignin-Degrading Heme Peroxidases. Enzyme Microb. Technol. 2002, 30 (4), 425– 444, DOI: 10.1016/S0141-0229(01)00521-X11https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38Xis1Oru7k%253D&md5=c15ddedae82e5d17170c35463b90e422Molecular biology and structure-function of lignin-degrading heme peroxidasesMartinez, Angel T.Enzyme and Microbial Technology (2002), 30 (4), 425-444CODEN: EMTED2; ISSN:0141-0229. (Elsevier Science Ireland Ltd.)A review. Three peroxidases involved in lignin degrdn. are produced by white-rot fungi. Lignin peroxidase (LiP) is characterized by oxidn. of high redox-potential arom. compds. (including veratryl alc.) whereas manganese peroxidase (MnP) requires Mn2+ to complete the catalytic cycle and forms Mn3+ chelates acting as diffusing oxidizers. Pleurotus and Bjerkandera versatile peroxidase (VP) is able to oxidize Mn2+ as well as nonphenolic arom. compds., phenols and dyes. Phanerochaete chrysosporium has two gene families including ten LiP-type and three MnP-type genes coding different isoenzymes expressed during secondary metab. Two VP genes have been recently cloned from Pleurotus eryngii. Phanerochaete chrysosporium MnP and P. eryngii VP are induced by H2O2, being Mn2+ involved in regulation of their transcript levels. At least eighteen more ligninolytic peroxidase genes have been cloned from other white-rot fungi. Protein sequence comparison reveals that typical MnP from P. chrysosporium and two other fungi (showing a longer C-terminal tail) are sepd. from other ligninolytic peroxidases, which form two main groups including P. chrysosporium LiP and Pleurotus peroxidases, resp. LiP and MnP crystal structures and VP theor. mol. models are available. The high redox potential of ligninolytic peroxidases seems related to the distance between heme iron and proximal histidine, and the ability of MnP to oxidize Mn2+ is due to a Mn-binding site formed by three acidic residues near the internal heme propionate. Pleurotus eryngii VP show higher sequence and structural affinities with P. chrysosporium LiP than MnP, but includes a Mn-binding site accounting for its ability to oxidize Mn2+. The functionality of this site was demonstrated by site-directed mutagenesis of MnP and VP. All fungal peroxidases, which exhibit similar topol. (11-12 helixes) and folding, also include binding sites for two structural Ca2+. Veratryl alc. was first modeled near LiP heme, but evidence for oxidn. at the protein surface via a long-range electron transfer pathway has accumulated. Chem. and site-directed mutagenesis modification confirmed that an exposed tryptophan is involved in veratryl alc. oxidn. however, multiple sites could be responsible for oxidn. of different arom. substrates and dyes by these peroxidases.
- 12Fernandez-Fueyo, E.; Ruiz-Duenas, F. J.; Ferreira, P.; Floudas, D.; Hibbett, D. S.; Canessa, P.; Larrondo, L. F.; James, T. Y.; Seelenfreund, D.; Lobos, S.; Polanco, R.; Tello, M.; Honda, Y.; Watanabe, T.; Watanabe, T.; San, R. J.; Kubicek, C. P.; Schmoll, M.; Gaskell, J.; Hammel, K. E.; St John, F. J.; Vanden Wymelenberg, A.; Sabat, G.; BonDurant, S. S.; Syed, K.; Yadav, J. S.; Doddapaneni, H.; Subramanian, V.; Lavin, J. L.; Oguiza, J. A.; Perez, G.; Pisabarro, A. G.; Ramirez, L.; Santoyo, F.; Master, E.; Coutinho, P. M.; Henrissat, B.; Lombard, V.; Magnuson, J. K.; Kues, U.; Hori, C.; Igarashi, K.; Samejima, M.; Held, B. W.; Barry, K. W.; LaButti, K. M.; Lapidus, A.; Lindquist, E. A.; Lucas, S. M.; Riley, R.; Salamov, A. A.; Hoffmeister, D.; Schwenk, D.; Hadar, Y.; Yarden, O.; de Vries, R. P.; Wiebenga, A.; Stenlid, J.; Eastwood, D.; Grigoriev, I. V.; Berka, R. M.; Blanchette, R. A.; Kersten, P.; Martínez, A. T.; Vicuna, R.; Cullen, D. Comparative Genomics of Ceriporiopsis Subvermispora and Phanerochaete Chrysosporium Provide Insight into Selective Ligninolysis. Proc. Natl. Acad. Sci. U. S. A. 2012, 109 (14), 5458– 5463, DOI: 10.1073/pnas.1119912109There is no corresponding record for this reference.
- 13Martínez, A. T.; Ruiz-Duenas, F. J.; Martínez, M. J.; Del Río, J. C.; Gutiérrez, A. Enzymatic Delignification of Plant Cell Wall: From Nature to Mill. Curr. Opin. Biotechnol. 2009, 20 (3), 348– 357, DOI: 10.1016/j.copbio.2009.05.00213https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXosVajtro%253D&md5=3c1ebfcd7c7e1d8c5e7fa43618025705Enzymatic delignification of plant cell wall: From nature to millMartinez, Angel T.; Ruiz-Duenas, Francisco J.; Martinez, Maria Jesus; del Rio, Jose C.; Gutierrez, AnaCurrent Opinion in Biotechnology (2009), 20 (3), 348-357CODEN: CUOBE3; ISSN:0958-1669. (Elsevier B.V.)A review. Lignin removal is a central issue in paper pulp manuf., and prodn. of other renewable chems., materials, and biofuels in future lignocellulose biorefineries. Biotechnol. can contribute to more efficient and environmentally sound deconstruction of plant cell wall by providing tailor-made biocatalysts based on the oxidative enzymes responsible for lignin attack in Nature. With this purpose, the already-known ligninolytic oxidoreductases are being improved using (rational and random-based) protein engineering, and still unknown enzymes will be identified by the application of the different "omics" technologies. Enzymic delignification will be soon at the pulp mill (combined with pitch removal) and our understanding of the reactions produced will increase by using modern techniques for lignin anal.
- 14Martínez, A. T.; Speranza, M.; Ruiz-Duenas, F. J.; Ferreira, P.; Camarero, S.; Guillen, F.; Martínez, M. J.; Gutiérrez, A.; Del Río, J. C. Biodegradation of Lignocellulosics: Microbial, Chemical, and Enzymatic Aspects of the Fungal Attack of Lignin. Int. Microbiol. 2005, 8 (3), 195– 20414https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXhtVemt7vL&md5=89d984d69398efe52208f415afc8419aBiodegradation of lignocellulosics: Microbial, chemical, and enzymatic aspects of the fungal attack of ligninMartinez, Angel T.; Speranza, Mariela; Ruiz-Duenas, Francisco J.; Ferreira, Patricia; Camarero, Susana; Guillen, Francisco; Martinez, Maria J.; Gutierrez, Ana; del Rio, Jose C.International Microbiology (2005), 8 (3), 195-204CODEN: INMIFW; ISSN:1139-6709. (Viguera Editores)A review. Wood is the main renewable material on Earth and is largely used as building material and in paper-pulp manufg. This review describes the compn. of lignocellulosic materials, the different processes by which fungi are able to alter wood, including decay patterns caused by white, brown, and soft-rot fungi, and fungal staining of wood. The chem., enzymic, and mol. aspects of the fungal attack of lignin, which represents the key step in wood decay, are also discussed. Modern anal. techniques to investigate fungal degrdn. and modification of the lignin polymer are reviewed, as are the different oxidative enzymes (oxidoreductases) involved in lignin degrdn. These include laccases, high redox potential ligninolytic peroxidases (lignin peroxidase, manganese peroxidase, and versatile peroxidase), and oxidases. Special emphasis is given to the reactions catalyzed, their synergistic action on lignin, and the structural bases for their unique catalytic properties. Broadening our knowledge of lignocellulose biodegrdn. processes should contribute to better control of wood-decaying fungi, as well as to the development of new biocatalysts of industrial interest based on these organisms and their enzymes.
- 15Eastwood, D. C.; Floudas, D.; Binder, M.; Majcherczyk, A.; Schneider, P.; Aerts, A.; Asiegbu, F. O.; Baker, S. E.; Barry, K.; Bendiksby, M.; Blumentritt, M.; Coutinho, P. M.; Cullen, D.; De Vries, R. P.; Gathman, A.; Goodell, B.; Henrissat, B.; Ihrmark, K.; Kauserud, H.; Kohler, A.; LaButti, K.; Lapidus, A.; Lavin, J. L.; Lee, Y. H.; Lindquist, E.; Lilly, W.; Lucas, S.; Morin, E.; Murat, C.; Oguiza, J. A.; Park, J.; Pisabarro, A. G.; Riley, R.; Rosling, A.; Salamov, A.; Schmidt, O.; Schmutz, J.; Skrede, I.; Stenlid, J.; Wiebenga, A.; Xie, X.; Kues, U.; Hibbett, D. S.; Hoffmeister, D.; Hogberg, N.; Martin, F.; Grigoriev, I. V.; Watkinson, S. C. The Plant Cell Wall-Decomposing Machinery Underlies the Functional Diversity of Forest Fungi. Science 2011, 333 (6043), 762– 765, DOI: 10.1126/science.1205411There is no corresponding record for this reference.
- 16Kerem, Z.; Jensen, K. A.; Hammel, K. E. Biodegradative Mechanism of the Brown Rot Basidiomycete Gloeophyllum Trabeum: Evidence for an Extracellular Hydroquinone-Driven Fenton Reaction. FEBS Lett. 1999, 446 (1), 49– 54, DOI: 10.1016/S0014-5793(99)00180-5There is no corresponding record for this reference.
- 17Suzuki, M. R.; Hunt, C. G.; Houtman, C. J.; Dalebroux, Z. D.; Hammel, K. E. Fungal Hydroquinones Contribute to Brown Rot of Wood. Environ. Microbiol. 2006, 8 (12), 2214– 2223, DOI: 10.1111/j.1462-2920.2006.01160.xThere is no corresponding record for this reference.
- 18Kijpornyongpan, T.; Schwartz, A.; Yaguchi, A.; Salvachúa, D. Systems Biology-Guided Understanding of White-Rot Fungi for Biotechnological Applications. A Review. iScience 2022, 25 (7), 104640 DOI: 10.1016/j.isci.2022.104640There is no corresponding record for this reference.
- 19Riley, R.; Salamov, A. A.; Brown, D. W.; Nagy, L. G.; Floudas, D.; Held, B. W.; Levasseur, A.; Lombard, V.; Morin, E.; Otillar, R.; Lindquist, E. A.; Sun, H.; LaButti, K. M.; Schmutz, J.; Jabbour, D.; Luo, H.; Baker, S. E.; Pisabarro, A. G.; Walton, J. D.; Blanchette, R. A.; Henrissat, B.; Martin, F.; Cullen, D.; Hibbett, D. S.; Grigoriev, I. V. Extensive Sampling of Basidiomycete Genomes Demonstrates Inadequacy of the White-Rot/Brown-Rot Paradigm for Wood Decay Fungi. Proc. Natl. Acad. Sci. U. S. A. 2014, 111 (27), 9923– 9928, DOI: 10.1073/pnas.1400592111There is no corresponding record for this reference.
- 20Martinez, A. T.; Rencoret, J.; Nieto, L.; Jimenez-Barbero, J.; Gutierrez, A.; Del Rio, J. C. Selective Lignin and Polysaccharide Removal in Natural Fungal Decay of Wood as Evidenced by in Situ Structural Analyses. Environ. Microbiol. 2011, 13 (1), 96– 107, DOI: 10.1111/j.1462-2920.2010.02312.xThere is no corresponding record for this reference.
- 21Yelle, D. J.; Ralph, J.; Lu, F.; Hammel, K. E. Evidence for Cleavage of Lignin by a Brown Rot Basidiomycete. Environ. Microbiol. 2008, 10 (7), 1844– 1849, DOI: 10.1111/j.1462-2920.2008.01605.x21https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXptVKgt7w%253D&md5=4bd3302894b0aa376a9038704fc36b4aEvidence for cleavage of lignin by a brown rot basidiomyceteYelle, Daniel J.; Ralph, John; Lu, Fachuang; Hammel, Kenneth E.Environmental Microbiology (2008), 10 (7), 1844-1849CODEN: ENMIFM; ISSN:1462-2912. (Blackwell Publishing Ltd.)Biodegrdn. by brown-rot fungi is quant. one of the most important fates of lignocellulose in nature. It has long been thought that these basidiomycetes do not degrade lignin significantly, and that their activities on this abundant arom. biopolymer are limited to minor oxidative modifications. Here we have applied a new technique for the complete solubilization of lignocellulose to show, by one-bond 1H-13C correlation NMR spectroscopy, that brown rot of spruce wood by Gloeophyllum trabeum resulted in a marked, non-selective depletion of all intermonomer side-chain linkages in the lignin. The resulting polymer retained most of its original arom. residues and was probably interconnected by new linkages that lack hydrogens and are consequently invisible in one-bond 1H-13C correlation spectra. Addnl. work is needed to characterize these linkages, but it is already clear that the arom. polymer remaining after extensive brown rot is no longer recognizable as lignin.
- 22Yelle, D. J.; Wei, D.; Ralph, J.; Hammel, K. E. Multidimensional NMR Analysis Reveals Truncated Lignin Structures in Wood Decayed by the Brown Rot Basidiomycete Postia Placenta. Environ. Microbiol. 2011, 13 (4), 1091– 1100, DOI: 10.1111/j.1462-2920.2010.02417.x22https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXmtV2jtrg%253D&md5=1b2ce8f5f064867f2ec261f46b7a4170Multidimensional NMR analysis reveals truncated lignin structures in wood decayed by the brown rot basidiomycete Postia placentaYelle, Daniel J.; Wei, Dongsheng; Ralph, John; Hammel, Kenneth E.Environmental Microbiology (2011), 13 (4), 1091-1100CODEN: ENMIFM; ISSN:1462-2912. (Wiley-Blackwell)Lignocellulose biodegrdn., an essential step in terrestrial carbon cycling, generally involves removal of the recalcitrant lignin barrier that otherwise prevents infiltration by microbial polysaccharide hydrolases. However, fungi that cause brown rot of wood, a major route for biomass recycling in coniferous forests, utilize wood polysaccharides efficiently while removing little of the lignin. The mechanism by which these basidiomycetes breach the lignin remains unclear. We used recently developed methods for solubilization and multidimensional 1H-13C soln.-state NMR spectroscopy of ball-milled lignocellulose to analyze aspen wood degraded by Postia placenta. The results showed that decay decreased the content of the principal arylglycerol-β-aryl ether linkage in the lignin by more than half, while increasing the frequency of several truncated lignin structures roughly fourfold over the level found in sound aspen. These new end-groups, consisting of benzaldehydes, benzoic acids and phenylglycerols, accounted for 6-7% of all original lignin subunits. Our results provide evidence that brown rot by P. placenta results in significant ligninolysis, which might enable infiltration of the wood by polysaccharide hydrolases even though the partially degraded lignin remains in situ. Recent work has revealed that the P. placenta genome encodes no ligninolytic peroxidases, but has also shown that this fungus produces an extracellular Fenton system. It is accordingly likely that P. placenta employs electrophilic reactive oxygen species such as hydroxyl radicals to disrupt lignin in wood.
- 23Filley, T. R.; Cody, G. D.; Goodell, B.; Jellison, J.; Noser, C.; Ostrofsky, A. Lignin Demethylation and Polysaccharide Decomposition in Spruce Sapwood Degraded by Brown Rot Fungi. Org. Geochem. 2002, 33 (2), 111– 124, DOI: 10.1016/S0146-6380(01)00144-923https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XhtFyktrc%253D&md5=12a528ca0226cf1a316268bfa763524fLignin demethylation and polysaccharide decomposition in spruce sapwood degraded by brown rot fungiFilley, T. R.; Cody, G. D.; Goodell, B.; Jellison, J.; Noser, C.; Ostrofsky, A.Organic Geochemistry (2002), 33 (2), 111-124CODEN: ORGEDE; ISSN:0146-6380. (Elsevier Science Ltd.)The org. residues produced in the brown-rot (BR) of wood by many basidiomycetes fungi are ubiquitous on most coniferous forest floors. This degraded wood tissue is characterized by low levels of polysaccharides and a high proportion of demethylated lignin with minor glycerol side-chain oxidn. Because of the selective enrichment in an arom. dihydroxy-rich lignin residue, the chem. and biol. reactivity of BR-degraded wood will be distinctly different from white rot, the other primary class of fungal wood decay, which typically produces oxidized, lignin-depleted residues. The biochem. mechanism by which BR fungi perform this distinctive degradative chem. is only starting to become known, and mol. studies which examine the chem. changes imparted to lignin over the long-term decay process are lacking. Using 13C-labeled tetramethylammonium hydroxide thermochemolysis (13C-TMAH) and solid-state 13C NMR, the authors investigated the relation between lignin oxidn./demethylation and polysaccharide metab. in a 32-wk time series study of spruce sapwood inoculated with either of two BR fungi (Postia placenta and Gloeophyllum trabeum). The findings demonstrate a close relation between lignin demethylation and polysaccharide loss and suggest demethylation may play a mechanistic role in polysaccharide loss, possibly by assisting in Fenton reactions where catechol/quinone oxidn. and cycling aids in iron redn. The residue remaining after 16 wk of decay is devoid of polysaccharides, in contrast to the 68% polysaccharide carbon present in the initial spruce, and exhibits an increased arom. dihydroxy content (resulting from demethylation of the 3-methoxyl carbon) of up to 22% of the lignin, as detd. by 13C-TMAH thermochemolysis. In a typical soil or porewater environment these chem. changes would make BR residues highly reactive toward redox-sensitive polyvalent metals (e.g. ferric iron) and likely to adsorb to metal hydroxide surfaces.
- 24Koenig, A. B.; Sleighter, R. L.; Salmon, E.; Hatcher, P. G. NMR Structural Characterization of Quercus Alba (White Oak) Degraded by the Brown Rot Fungus. Laetiporus Sulphureus. J. Wood Chem. Technol. 2010, 30 (1), 61– 85, DOI: 10.1080/02773810903276668There is no corresponding record for this reference.
- 25Qi, J.; Jia, L.; Liang, Y.; Luo, B.; Zhao, R.; Zhang, C.; Wen, J.; Zhou, Y.; Fan, M.; Xia, Y. Fungi’s Selectivity in the Biodegradation of Dendrocalamus Sinicus Decayed by White and Brown Rot Fungi. Ind. Crops Prod. 2022, 188, 115726 DOI: 10.1016/j.indcrop.2022.115726There is no corresponding record for this reference.
- 26Brinkmann, K.; Blaschke, L.; Polle, A. Comparison of Different Methods for Lignin Determination as a Basis for Calibration of near-Infrared Reflectance Spectroscopy and Implications of Lignoproteins. J. Chem. Ecol. 2002, 28 (12), 2483– 2501, DOI: 10.1023/A:1021484002582There is no corresponding record for this reference.
- 27Hatfield, R.; Fukushima, R. S. Can Lignin Be Accurately Measured?. Crop Sci. 2005, 45 (3), 832– 839, DOI: 10.2135/cropsci2004.023827https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXks1Wrurk%253D&md5=67c1f208b4a29d4864c4c360de13aa29Can lignin be accurately measured?Hatfield, Ronald; Fukushima, Romualdo S.Crop Science (2005), 45 (3), 832-839CODEN: CRPSAY; ISSN:0011-183X. (Crop Science Society of America)A review. Forages serve an important role in providing nutrients to ruminants while providing pos. benefits to the environment. Forage cell wall digestibility is incomplete because of several structural features within the wall, but digestion is mostly inversely correlated with the amt. of lignification that has occurred during cell wall development. Lignin is a hydrophobic polymer formed through enzyme-mediated radical coupling of monolignols, mainly coniferyl and sinapyl alcs. The polymer is highly resistant to degrdn. and generally passes through the ruminant unmodified. Though lignin is resistant to degrdn., it is not easily quantified within various types of forages. Numerous methods have been developed over the years to measure lignin levels in different plant species. Most frequently used among workers involved with forage development or utilization are the acid detergent, Mason, and permanganate lignin methods. More recently, acetyl bromide has received attention as a possible lignin detn. method. The acetyl bromide method is dependent on detg. the absorbance of the ext. in which all the lignin of a sample has been dissolved. Each of these methods gives different lignin values for the same type of forage sample. For example, acid detergent, Mason, permanganate, and acetyl bromide lignin methods give quite different values for alfalfa stems: 93, 145, 158, and 135 g lignin kg-1 cell wall, resp. These differences can be even greater for grasses: 25, 77,45, and 92 g kg-1 cell wall from corn (Zea mays L.) stalks analyzed by acid detergent, Mason, permanganate, and acetyl bromide lignin methods, resp. This paper will discuss the different lignin detn. methods and highlight the advantages and disadvantages of each as they relate to forage sample anal.
- 28Moreira-Vilar, F. C.; De Cassia Siqueira-Soares, R.; Finger-Teixeira, A.; De Oliveira, D. M.; Ferro, A. P.; Da Rocha, G. J.; Maria de Lourdes, L. F.; Dos Santos, W. D.; Ferrarese-Filho, O. The Acetyl Bromide Method Is Faster, Simpler and Presents Best Recovery of Lignin in Different Herbaceous Tissues Than Klason and Thioglycolic Acid Methods. PLoS One 2014, 9 (10), e110000 DOI: 10.1371/journal.pone.011000028https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvVOqtr%252FK&md5=e72ab2af2eaeeecf2d5796b0ce01b349The acetyl bromide method is faster, simpler and presents best recovery of lignin in different herbaceous tissues than Klason and thioglycolic acid methodsMoreira-Vilar, Flavia Carolina; de Cassia Siqueira-Soares, Rita; Finger-Teixeira, Aline; de Oliveira, Dyoni Matias; Ferro, Ana Paula; da Rocha, George Jackson; de Lourdes L. Ferrarese, Maria; dos Santos, Wanderley Dantas; Ferrarese-Filho, OsvaldoPLoS One (2014), 9 (10), e110000/1-e110000/7, 7 pp.CODEN: POLNCL; ISSN:1932-6203. (Public Library of Science)We compared the amt. of lignin as detd. by the three most traditional methods for lignin measurement in three tissues (sugarcane bagasse, soybean roots and soybean seed coat) contrasting for lignin amt. and compn. Although all methods presented high reproducibility, major inconsistencies among them were found. The amt. of lignin detd. by thioglycolic acid method was severely lower than that provided by the other methods (up to 95%) in all tissues analyzed. Klason method was quite similar to acetyl bromide in tissues contg. higher amts. of lignin, but presented lower recovery of lignin in the less lignified tissue. To investigate the causes of the inconsistencies obsd., we detd. the monomer compn. of all plant materials, but found no correlation. We found that the low recovery of lignin presented by the thioglycolic acid method were due losses of lignin in the residues disposed throughout the procedures. The prodn. of furfurals by acetyl bromide method does not explain the differences obsd. The acetyl bromide method is the simplest and fastest among the methods evaluated presenting similar or best recovery of lignin in all the tissues assessed.
- 29van Erven, G.; de Visser, R.; Merkx, D. W. H.; Strolenberg, W.; de Gijsel, P.; Gruppen, H.; Kabel, M. A. Quantification of Lignin and Its Structural Features in Plant Biomass Using 13C Lignin as Internal Standard for Pyrolysis-GC-SIM-MS. Anal. Chem. 2017, 89 (20), 10907– 10916, DOI: 10.1021/acs.analchem.7b0263229https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsFeit7nN&md5=42c592cc448c6fdde3a61f8f00c933c5Quantification of Lignin and Its Structural Features in Plant Biomass Using 13C Lignin as Internal Standard for Pyrolysis-GC-SIM-MSvan Erven, Gijs; de Visser, Ries; Merkx, Donny W. H.; Strolenberg, Willem; de Gijsel, Peter; Gruppen, Harry; Kabel, Mirjam A.Analytical Chemistry (Washington, DC, United States) (2017), 89 (20), 10907-10916CODEN: ANCHAM; ISSN:0003-2700. (American Chemical Society)Understanding the mechanisms underlying plant biomass recalcitrance at the mol. level can only be achieved by accurate analyses of both the content and structural features of the mols. involved. Current quantification of lignin is, however, mainly based on unspecific gravimetric anal. after sulfuric acid hydrolysis. Hence, the research aimed at specific lignin quantification with concurrent characterization of its structural features. Hereto, for the first time, a polymeric 13C lignin was used as internal std. (IS) for lignin quantification via anal. pyrolysis coupled to gas chromatog. with mass-spectrometric detection in selected ion monitoring mode (py-GC-SIM-MS). In addn., relative response factors (RRFs) for the various pyrolysis products obtained were detd. and applied. First, 12C and 13C lignin were isolated from nonlabeled and uniformly 13C labeled wheat straw, resp., and characterized by heteronuclear single quantum coherence (HSQC), NMR, and py-GC/MS. The two lignin isolates were found to have identical structures. Second, 13C-IS based lignin quantification by py-GC-SIM-MS was validated in reconstituted biomass model systems with known contents of the 12C lignin analog and was shown to be extremely accurate (>99.9%, R2 > 0.999) and precise (RSD < 1.5%). Third, 13C-IS based lignin quantification was applied to four common pomaceous biomass sources (wheat straw, barley straw, corn stover, and sugar cane bagasse), and lignin contents were in good agreement with the total gravimetrically detd. lignin contents. The robust method proves to be a promising alternative for the high-throughput quantification of lignin in milled biomass samples directly and simultaneously provides a direct insight into the structural features of lignin.
- 30van Erven, G.; Nayan, N.; Sonnenberg, A. S. M.; Hendriks, W. H.; Cone, J. W.; Kabel, M. A. Mechanistic Insight in the Selective Delignification of Wheat Straw by Three White-Rot Fungal Species through Quantitative 13C-IS py-GC-MS and Whole Cell Wall HSQC NMR. Biotechnol. Biofuels 2018, 11, 262, DOI: 10.1186/s13068-018-1259-9There is no corresponding record for this reference.
- 31van Erven, G.; Wang, J.; Sun, P.; de Waard, P.; van der Putten, J.; Frissen, G. E.; Gosselink, R. J. A.; Zinovyev, G.; Potthast, A.; van Berkel, W. J. H.; Kabel, M. A. Structural Motifs of Wheat Straw Lignin Differ in Susceptibility to Degradation by the White-Rot Fungus Ceriporiopsis Subvermispora. ACS Sustainable Chem. Eng. 2019, 7 (24), 20032– 20042, DOI: 10.1021/acssuschemeng.9b05780There is no corresponding record for this reference.
- 32Cen, E. 113–1; Durability of Wood and Wood-Based Products. Test Method against Wood Destroying Basidiomycetes. Part 1: Assessment of Biocidal Efficacy of Wood Preservatives; European Committee for Standardization: Brussels, Belgium, 2020.There is no corresponding record for this reference.
- 33Cen, E. 113–2; Durability of Wood and Wood-Based Products. Test Method against Wood Destroying Basidiomycetes. Part 2: Assessment of Inherent or Enhanced Durability; European Committee for Standardization: Brussels, Belgium, 2020.There is no corresponding record for this reference.
- 34AWPA Laboratory Method for Evaluating the Decay Resistance of Wood-Based Materials against Pure Basidiomycete Cultures: Soil/Block Test . Standard E10–22. AWPA Std. Methods 2022.There is no corresponding record for this reference.
- 35ENV 807 Wood Preservatives–Determination of the Effectiveness against Soft Rotting Micro-Fungi and Other Soil Inhabiting Micro-Organisms; European Committee for Standardization: Brussels, Belgium, 2001.There is no corresponding record for this reference.
- 36Sluiter, A.; Hames, B.; Ruiz, R.; Scarlata, C.; Sluiter, J.; Templeton, D.; Crocker, D. Determination of Structural Carbohydrates and Lignin in Biomass. Lab. Anal. Proced. 2008, 1617 (1), 1– 16There is no corresponding record for this reference.
- 37Dence, C. W. The Determination of Lignin. In Methods in Lignin Chemistry, Lin, S. Y.; Dence, C. W., Eds.; Springer: Berlin Heidelberg, 1992; pp 33– 61.There is no corresponding record for this reference.
- 38Jones, D. B. Factors for Converting Percentages of Nitrogen in Foods and Feeds into Percentages of Proteins; US Department of Agriculture: 1931.There is no corresponding record for this reference.
- 39van Erven, G.; de Visser, R.; de Waard, P.; van Berkel, W. J. H.; Kabel, M. A. Uniformly 13C Labeled Lignin Internal Standards for Quantitative Pyrolysis-GC-MS Analysis of Grass and Wood. ACS Sustainable Chem. Eng. 2019, 7 (24), 20070– 20076, DOI: 10.1021/acssuschemeng.9b0592639https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXitFKqu7rL&md5=80c588a00817dbc8c9106e82816b1272Uniformly 13C Labeled Lignin Internal Standards for Quantitative Pyrolysis-GC-MS Analysis of Grass and Woodvan Erven, Gijs; de Visser, Ries; de Waard, Pieter; van Berkel, Willem J. H.; Kabel, Mirjam A.ACS Sustainable Chemistry & Engineering (2019), 7 (24), 20070-20076CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)With the ever-advancing lignocellulose valorization strategies, lignin analyses need to advance as well. However, lignin quantification still heavily relies on unspecific, time- and sample-consuming gravimetric, and spectrophotometric analyses. Here, we demonstrate that lignin isolates from uniformly 13C-labeled wheat straw, willow, and douglas fir serve as "ideal" internal stds. for pyrolysis gas chromatog. high-resoln. mass spectrometry (py-GC-HR-MS) analyses of plant biomass, allowing the accurate and precise quantification and structural characterization of lignin in grasses, hardwoods, and softwoods. The 13C lignin internal stds. were comprehensively structurally characterized by HSQC NMR and py-GC-HR-MS analyses, and their application for lignin quantification was validated in biomass model systems and in actual plant biomass. For all botanical origins and species, the lignin content was detd. within 5% relative deviation of the Klason benchmark. These results establish the capability of the developed anal. platform to selectively quantify and structurally characterize lignin simultaneously and demonstrate a valuable addn. to the lignin anal. toolbox. Uniformly 13C-labeled lignin isolates enable the concurrent quantification and structural characterization of lignin in grasses, hardwoods, and softwoods by pyrolysis gas chromatog. high-resoln. mass spectrometry.
- 40van Erven, G.; Hendrickx, P.; Al Hassan, M.; Beelen, B.; op den Kamp, R.; Keijsers, E.; van der Cruijsen, K.; Trindade, L. M.; Harmsen, P. F. H.; van Peer, A. F. Plant Genotype and Fungal Strain Harmonization Improves Miscanthus Sinensis Conversion by the White-Rot Fungus Ceriporiopsis Subvermispora. ACS Sustainable Chem. Eng. 2023, 11 (17), 6752– 6764, DOI: 10.1021/acssuschemeng.3c00815There is no corresponding record for this reference.
- 41Del Río, J. C.; Rencoret, J.; Prinsen, P.; Martínez, Á. T.; Ralph, J.; Gutiérrez, A. Structural Characterization of Wheat Straw Lignin as Revealed by Analytical Pyrolysis, 2D-NMR, and Reductive Cleavage Methods. J. Agric. Food Chem. 2012, 60 (23), 5922– 5935, DOI: 10.1021/jf301002n41https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xnt1Wkt7k%253D&md5=2b9ed69b99c329c6ed8fd460820f837aStructural Characterization of Wheat Straw Lignin as Revealed by Analytical Pyrolysis, 2D-NMR, and Reductive Cleavage Methodsdel Rio, Jose C.; Rencoret, Jorge; Prinsen, Pepijn; Martinez, Angel T.; Ralph, John; Gutierrez, AnaJournal of Agricultural and Food Chemistry (2012), 60 (23), 5922-5935CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)The structure of the lignin in wheat straw has been investigated by a combination of anal. pyrolysis, 2D-NMR, and derivatization followed by reductive cleavage (DFRC). It is a p-hydroxyphenyl-guaiacyl-syringyl lignin (with an H:G:S ratio of 6:64:30) assocd. with p-coumarates and ferulates. 2D-NMR indicated that the main substructures present are β-O-4'-ethers (∼75%), followed by phenylcoumarans (∼11%), with lower amts. of other typical units. A major new finding is that the flavone tricin is apparently incorporated into the lignins. NMR and DFRC indicated that the lignin is partially acylated (∼10%) at the γ-carbon, predominantly with acetates that preferentially acylate guaiacyl (12%) rather than syringyl (1%) units; in dicots, acetylation is predominantly on syringyl units. P-Coumarate esters were barely detectable (<1%) on monomer conjugates released by selectively cleaving β-ethers in DFRC, indicating that they might be preferentially involved in condensed or terminal structures.
- 42Ralph, S. A.; Ralph, J.; Lu, F. NMR Database of Lignin and Cell Wall Model Compounds. http://www.glbrc.org/databases_and_software/nmrdatabase/. Accessed 2024–05–01.There is no corresponding record for this reference.
- 43Gosselink, R. J. A.; van Dam, J. E. G.; de Jong, E.; Scott, E. L.; Sanders, J. P. M.; Li, J.; Gellerstedt, G. Fractionation, Analysis, and PCA Modeling of Properties of Four Technical Lignins for Prediction of Their Application Potential in Binders. Holzforschung 2010, 64 (2), 193– 200, DOI: 10.1515/hf.2010.02343https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXivFCmtbs%253D&md5=3f6312b54572e001f290b7ad8a5ae779Fractionation, analysis, and PCA modeling of properties of four technical lignins for prediction of their application potential in bindersGosselink, Richard J. A.; van Dam, Jan E. G.; de Jong, Ed; Scott, Elinor L.; Sanders, Johan P. M.; Li, Jiebing; Gellerstedt, GoeranHolzforschung (2010), 64 (2), 193-200CODEN: HOLZAZ; ISSN:0018-3830. (Walter de Gruyter GmbH & Co. KG)Functional properties of tech. lignins need to be characterized in more detail to become a higher added value renewable raw material for the chem. industry. The suitability of a lignin from different plants or trees obtained by different tech. processes can only be predicted for selected applications, such as binders, if reliable anal. data are available. In the present paper, structure dependent properties of four industrial lignins were analyzed before and after successive org. solvent extns. The lignins have been fractionated according to their molar mass by these solvents extns. Kraft and soda lignins were shown to have different molar mass distributions and chem. compns. Lignin carbohydrate complexes are most recalcitrant for extn. with org. solvents. These poorly sol. complexes can consist of up to 34% of carbohydrates in soda lignins. Modeling by principal component anal. (PCA) was performed aiming at prediction of the application potential of different lignins for binder prodn. The lignins and their fractions could be classified in different clusters based on their properties, which are structure dependent. Kraft soft-wood lignins show the highest potential for plywood binder application followed by hardwood soda lignin and the fractions of Sarkanda grass soda lignin with medium molar mass. Expectedly, the softwood lignins contain the highest no. of reactive sites in ortho positions to the phenolic OH group. Moreover, these lignins have a low level of impurities and medium molar mass.
- 44Granata, A.; Argyropoulos, D. S. 2-Chloro-4,4,5,5-Tetramethyl-1,3,2-Dioxaphospholane, a Reagent for the Accurate Determination of the Uncondensed and Condensed Phenolic Moieties in Lignins. J. Agric. Food Chem. 1995, 43 (6), 1538– 1544, DOI: 10.1021/jf00054a02344https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2MXlvFWrtrY%253D&md5=c70e0fa359d869c64e5500f305a68e992-Chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane, a Reagent for the Accurate Determination of the Uncondensed and Condensed Phenolic Moieties in LigninsGranata, Alessandro; Argyropoulos, Dimitris S.Journal of Agricultural and Food Chemistry (1995), 43 (6), 1538-44CODEN: JAFCAU; ISSN:0021-8561. (American Chemical Society)The use of 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane as a phosphitylation reagent in quant. 31P NMR anal. of the hydroxyl groups in lignins has been thoroughly examd., and an exptl. protocol recommended for spectra acquisition has been developed. Quant. anal. of six "std. lignins" gave results comparable to those obtained by other methods of anal. Excellent resoln. of the various phenolic hydroxyl environments including those present in condensed moieties was obsd. However, this was at the expense of resoln. in the aliph. hydroxyl region, where no distinction between primary, secondary, and the erythro and threo forms of the secondary hydroxyls of the β-O-4 bonds can be made.
- 45Constant, S.; Wienk, H. L. J.; Frissen, A. E.; Peinder, P. d.; Boelens, R.; van Es, D. S.; Grisel, R. J. H.; Weckhuysen, B. M.; Huijgen, W. J. J.; Gosselink, R. J. A.; Bruijnincx, P. C. A. New Insights into the Structure and Composition of Technical Lignins: A Comparative Characterisation Study. Green Chem. 2016, 18 (9), 2651– 2665, DOI: 10.1039/C5GC03043A45https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28Xit1Oru7c%253D&md5=316cc097824f176d95a4ed876013d3efNew insights into the structure and composition of technical lignins: a comparative characterisation studyConstant, Sandra; Wienk, Hans L. J.; Frissen, Augustinus E.; de Peinder, Peter; Boelens, Rolf; van Es, Daan S.; Grisel, Ruud J. H.; Weckhuysen, Bert M.; Huijgen, Wouter J. J.; Gosselink, Richard J. A.; Bruijnincx, Pieter C. A.Green Chemistry (2016), 18 (9), 2651-2665CODEN: GRCHFJ; ISSN:1463-9262. (Royal Society of Chemistry)Detailed insight into the structure and compn. of industrial (tech.) lignins is needed to devise efficient thermal, bio- or chemocatalytic valorisation strategies. Six such tech. lignins covering three main industrial pulping methods (Indulin AT Kraft, Protobind 1000 soda lignin and Alcell, poplar, spruce and wheat straw organosolv lignins) were comprehensively characterised by lignin compn. anal., FT-IR, pyrolysis-GC-MS, quant. 31P and 2D HSQC NMR anal. and molar mass distribution by Size Exclusion Chromatog. (SEC). A comparison of nine SEC methods, including the first anal. of lignins with com. alk. SEC columns, showed molar masses to vary considerably, allowing some recommendations to be made. The lignin molar mass decreased in the order: Indulin Kraft > soda P1000 > Alcell > OS-W ∼ OS-P ∼ OS-S, regardless of the SEC method chosen. Structural identification and quantification of arom. units and inter-unit linkages indicated that all tech. lignins, including the organosolv ones, have considerably been degraded and condensed by the pulping process. Importantly, low amts. of β- ether linkages were found compared to literature values for protolignin and lignins obtained by other, milder isolation processes. Stilbenes and ether furfural units could also be identified in some of the lignins. Taken together, the insights gained in the structure of the tech. lignins, in particular, the low β-O-4 contents, carry implications for the design of lignin valorisation strategies including (catalytic) depolymn. and material applications.
- 46Rumpf, J.; Burger, R.; Schulze, M. Statistical evaluation of DPPH, ABTS, FRAP, and Folin-Ciocalteu assays to assess the antioxidant capacity of lignins. Int. J. Biol. Macromol. 2023, 233, 123470 DOI: 10.1016/j.ijbiomac.2023.12347046https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXis1yltrk%253D&md5=4a7a6c4ce3d4a1dee474a02f43e4e042Statistical evaluation of DPPH, ABTS, FRAP, and Folin-Ciocalteu assays to assess the antioxidant capacity of ligninsRumpf, Jessica; Burger, Rene; Schulze, MargitInternational Journal of Biological Macromolecules (2023), 233 (), 123470CODEN: IJBMDR; ISSN:0141-8130. (Elsevier B.V.)This research studies in detail four different assays, namely DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), FRAP (ferric ion reducing antioxidant potential) and FC (Folin-Ciocalteu), to det. the antioxidant capacity of std. substances as well as 50 organosolv lignins, and two kraft lignins. The coeff. of variation was detd. for each method and was lowest for ABTS and highest for DPPH. The best correlation was found for FRAP and FC, which both rely on a single electron transfer mechanism. A good correlation between ABTS, FRAP and FC, resp., could be obsd., even though ABTS relies on a more complex reaction mechanism. The DPPH assay merely correlates with the others, implying that it reflects different antioxidative attributes due to a different reaction mechanism. Lignins obtained from paulownia and silphium have been investigated for the first time regarding their antioxidant capacity. Paulownia lignin is in the same range as beech wood lignin, while silphium lignin resembles wheat straw lignin. Miscanthus lignin is an exception from the grass lignins and possesses a significantly higher antioxidant capacity. All lignins possess a good antioxidant capacity and thus are promising candidates for various applications, e. g. as additives in food packaging or for biomedical purposes.
- 47Arantes, V.; Goodell, B. Current Understanding of Brown-Rot Fungal Biodegradation Mechanisms: A Review. In Deterioration and Protection of Sustainable Biomaterials, ACS Symposium Series, American Chemical Society: 2014; Vol. 1158, pp 3– 21.There is no corresponding record for this reference.
- 48Zhang, J.; Silverstein, K. A. T.; Castaño, J. D.; Figueroa, M.; Schilling, J. S. Gene Regulation Shifts Shed Light on Fungal Adaption in Plant Biomass Decomposers. mBio 2019, 10 (6), e02176-19 DOI: 10.1128/mBio.02176-19There is no corresponding record for this reference.
- 49Duran, K.; Kohlstedt, M.; van Erven, G.; Klostermann, C. E.; America, A. H. P.; Bakx, E.; Baars, J. J. P.; Gorissen, A.; de Visser, R.; de Vries, R. P.; Wittmann, C.; Comans, R. N. J.; Kuyper, T. W.; Kabel, M. A. From 13C-Lignin to 13C-Mycelium: Agaricus Bisporus Uses Polymeric Lignin as a Carbon Source. Sci. Adv. 2024, 10 (16), eadl3419 DOI: 10.1126/sciadv.adl3419There is no corresponding record for this reference.
- 50Duran, K.; Miebach, J.; van Erven, G.; Baars, J. J. P.; Comans, R. N. J.; Kuyper, T. W.; Kabel, M. A. Oxidation-Driven Lignin Removal by Agaricus Bisporus from Wheat Straw-Based Compost at Industrial Scale. Int. J. Biol. Macromol. 2023, 246, 125575 DOI: 10.1016/j.ijbiomac.2023.125575There is no corresponding record for this reference.
- 51van Kuijk, S. J. A.; Sonnenberg, A. S. M.; Baars, J. J. P.; Hendriks, W. H.; del Río, J. C.; Rencoret, J.; Gutiérrez, A.; de Ruijter, N. C. A.; Cone, J. W. Chemical Changes and Increased Degradability of Wheat Straw and Oak Wood Chips Treated with the White Rot Fungi Ceriporiopsis Subvermispora and Lentinula Edodes. Biomass Bioenergy 2017, 105, 381– 391, DOI: 10.1016/j.biombioe.2017.07.00351https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhtlCqtLbP&md5=5a99151c39c6085b6f0bd3f755a08bcfChemical changes and increased degradability of wheat straw and oak wood chips treated with the white rot fungi Ceriporiopsis subvermispora and Lentinula edodesvan Kuijk, Sandra J. A.; Sonnenberg, Anton S. M.; Baars, Johan J. P.; Hendriks, Wouter H.; del Rio, Jose C.; Rencoret, Jorge; Gutierrez, Ana; de Ruijter, Norbert C. A.; Cone, John W.Biomass and Bioenergy (2017), 105 (), 381-391CODEN: BMSBEO; ISSN:0961-9534. (Elsevier Ltd.)Wheat straw and oak wood chips were incubated with Ceriporiopsis subvermispora and Lentinula edodes for 8 wk. Samples from the fungal treated substrates were collected every week for chem. characterization. L. edodes continuously grew during the 8 wk on both wheat straw and oak wood chips, as detd. by the ergosterol mass fraction of the dry biomass. C. subvermispora colonized both substrates during the first week, stopped growing on oak wood chips, and resumed growth after 6 wk on wheat straw. Detergent fiber anal. and pyrolysis coupled to gas chromatog./mass spectrometry showed a selective lignin degrdn. in wheat straw, although some carbohydrates were also degraded. L. edodes continuously degraded lignin and hemicelluloses in wheat straw while C. subvermispora degraded lignin and hemicelluloses only during the first 5 wk of treatment after which cellulose degrdn. started. Both fungi selectively degraded lignin in wood chips. After 4 wk of treatment, no significant changes in chem. compn. were detected. In contrast to L. edodes, C. subvermispora produced alkylitaconic acids during fungal treatment, which paralleled the degrdn. and modification of lignin indicating the importance of these compds. in delignification. Light microscopy visualized a dense structure of wood chips which was difficult to penetrate by the fungi, explaining the relative lower lignin degrdn. compared to wheat straw measured by chem. anal. All these changes resulted in an increased in in vitro rumen degradability of wheat straw and oak wood chips. In addn., more glucose and xylose were released after enzymic saccharification of fungal treated wheat straw compared to untreated material.
- 52Chen, F.; Tobimatsu, Y.; Havkin-Frenkel, D.; Dixon, R. A.; Ralph, J. A Polymer of Caffeyl Alcohol in Plant Seeds. Proc. Natl. Acad. Sci. U. S. A. 2012, 109 (5), 1772– 1777, DOI: 10.1073/pnas.112099210952https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XitlKltL8%253D&md5=25b17753f76803139c45bbba98ff8623A polymer of caffeyl alcohol in plant seedsChen, Fang; Tobimatsu, Yuki; Havkin-Frenkel, Daphna; Dixon, Richard A.; Ralph, JohnProceedings of the National Academy of Sciences of the United States of America (2012), 109 (5), 1772-1777, S1772/1-S1772/9CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)Lignins are complex phenylpropanoid polymers mostly assocd. with plant secondary cell walls. Lignins arise primarily via oxidative polymn. of the three monolignols, p-coumaryl, coniferyl, and sinapyl alcs. Of the two hydroxycinnamyl alcs. that represent incompletely methylated biosynthetic products (and are not usually considered to be monolignols), 5-hydroxyconiferyl alc. is now well established as incorporating into angiosperm lignins, but incorporation of caffeyl alc. has not been shown. We report here the presence of a homopolymer of caffeyl alc. in the seed coats of both monocot and dicot plants. This polymer (C-lignin) is deposited to high concns. in the seed coat during the early stages of seed development in the vanilla orchid (Vanilla planifolia), and in several members of the Cactaceae. The lignin in other parts of the Vanilla plant is conventionally biosynthesized from coniferyl and sinapyl alcs. Some species of cacti contain only C-lignin in their seeds, whereas others contain only classical guaiacyl/syringyl lignin (derived from coniferyl and sinapyl alcs.). NMR spectroscopic anal. revealed that the Vanilla seed-coat polymer was massively comprised of benzodioxane units and was structurally similar to the polymer synthesized in vitro by peroxidase-catalyzed polymn. of caffeyl alc. CD spectroscopy did not detect any optical activity in the seed polymer. These data support the contention that the C-lignin polymer is produced in vivo via combinatorial oxidative radical coupling that is under simple chem. control, a mechanism analogous to that theorized for classical lignin biosynthesis.
- 53Tobimatsu, Y.; Chen, F.; Nakashima, J.; Escamilla-Treviño, L. L.; Jackson, L.; Dixon, R. A.; Ralph, J. Coexistence but Independent Biosynthesis of Catechyl and Guaiacyl/Syringyl Lignin Polymers in Seed Coats. Plant Cell 2013, 25 (7), 2587– 2600, DOI: 10.1105/tpc.113.11314253https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsVKksbrO&md5=5447c49874ad69816cddd84ecef91cc8Coexistence but independent biosynthesis of catechyl and guaiacyl/syringyl lignin polymers in seed coatsTobimatsu, Yuki; Chen, Fang; Nakashima, Jin; Escamilla-Trevino, Luis L.; Jackson, Lisa; Dixon, Richard A.; Ralph, JohnPlant Cell (2013), 25 (7), 2587-2600CODEN: PLCEEW; ISSN:1040-4651. (American Society of Plant Biologists)Lignins are phenylpropanoid polymers, derived from monolignols, commonly found in terrestrial plant secondary cell walls. We recently reported evidence of an unanticipated catechyl lignin homopolymer (C lignin) derived solely from caffeyl alc. in the seed coats of several monocot and dicot plants. We previously identified plant seeds that possessed either C lignin or traditional guaiacyl/syringyl (G/S) lignins, but not both. Here, we identified several dicot plants (Euphorbiaceae and Cleomaceae) that produce C lignin together with traditional G/S lignins in their seed coats. Soln.-state NMR analyses, along with an in vitro lignin polymn. study, detd. that there is, however, no copolymn. detectable (i.e., that the synthesis and polymn. of caffeyl alc. and conventional monolignols in vivo is spatially and/or temporally sepd.). In particular, the deposition of G and C lignins in Cleome hassleriana seed coats is developmentally regulated during seed maturation; C lignin appears successively after G lignin within the same testa layers, concurrently with apparent loss of the functionality of O-methyltransferases, which are key enzymes for the conversion of C to G lignin precursors. This study exemplifies the flexible biosynthesis of different types of lignin polymers in plants dictated by substantial, but poorly understood, control of monomer supply by the cells.
- 54Meng, X.; Crestini, C.; Ben, H.; Hao, N.; Pu, Y.; Ragauskas, A. J.; Argyropoulos, D. S. Determination of Hydroxyl Groups in Biorefinery Resources Via Quantitative 31P NMR Spectroscopy. Nat. Protoc. 2019, 14 (9), 2627– 2647, DOI: 10.1038/s41596-019-0191-154https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhsFertb3F&md5=1e3de893abc1e41a40406d8a7d3a23f8Determination of hydroxyl groups in biorefinery resources via quantitative 31P NMR spectroscopyMeng, Xianzhi; Crestini, Claudia; Ben, Haoxi; Hao, Naijia; Pu, Yunqiao; Ragauskas, Arthur J.; Argyropoulos, Dimitris S.Nature Protocols (2019), 14 (9), 2627-2647CODEN: NPARDW; ISSN:1750-2799. (Nature Research)The anal. of chem. structural characteristics of biorefinery product streams (such as lignin and tannin) has advanced substantially over the past decade, with traditional wet-chem. techniques being replaced or supplemented by NMR methodologies. Quant. 31P NMR spectroscopy is a promising technique for the anal. of hydroxyl groups because of its unique characterization capability and broad potential applicability across the biorefinery research community. This protocol describes procedures for (i) the prepn./solubilization of lignin and tannin, (ii) the phosphitylation of their hydroxyl groups, (iii) NMR acquisition details, and (iv) the ensuing data analyses and means to precisely calc. the content of the different types of hydroxyl groups. Compared with traditional wet-chem. techniques, the technique of quant. 31P NMR spectroscopy offers unique advantages in measuring hydroxyl groups in a single spectrum with high signal resoln. The method provides complete quant. information about the hydroxyl groups with small amts. of sample (~ 30 mg) within a relatively short exptl. time (~ 30-120 min).
- 55Kirk, T. K.; Tien, M.; Kersten, P. J.; Mozuch, M. D.; Kalyanaraman, B. Ligninase of Phanerochaete Chrysosporium. Mechanism of Its Degradation of the Non-Phenolic Arylglycerol β-Aryl Ether Substructure of Lignin. Biochem. J. 1986, 236 (1), 279– 287, DOI: 10.1042/bj2360279There is no corresponding record for this reference.
- 56Wu, X.; Smet, E.; Brandi, F.; Raikwar, D.; Zhang, Z.; Maes, B. U. W.; Sels, B. F. Advancements and Perspectives toward Lignin Valorization Via O-Demethylation. Angew. Chem., Int. Ed. 2024, 63 (10), e202317257 DOI: 10.1002/anie.202317257There is no corresponding record for this reference.
- 57Golten, O.; Ayuso-Fernández, I.; Hall, K. R.; Stepnov, A. A.; Sørlie, M.; Røhr, Å. K.; Eijsink, V. G. H. Reductants Fuel Lytic Polysaccharide Monooxygenase Activity in a pH-dependent Manner. FEBS Lett. 2023, 597 (10), 1363– 1374, DOI: 10.1002/1873-3468.1462957https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXpsFGjurg%253D&md5=cdd019aad10a9a69041caa3dc3ec1223Reductants fuel lytic polysaccharide monooxygenase activity in a pH-dependent mannerGolten, Ole; Ayuso-Fernandez, Ivan; Hall, Kelsi R.; Stepnov, Anton A.; Soerlie, Morten; Roehr, Ssmund Kjendseth; Eijsink, Vincent G. H.FEBS Letters (2023), 597 (10), 1363-1374CODEN: FEBLAL; ISSN:0014-5793. (Wiley-Blackwell)Polysaccharide-degrading mono-copper lytic polysaccharide monooxygenases (LPMOs) are efficient peroxygenases that require electron donors (reductants) to remain in the active Cu(I) form and to generate the H2O2 co-substrate from mol. oxygen. Here, we show how commonly used reductants affect LPMO catalysis in a pH-dependent manner. Between pH 6.0 and 8.0, reactions with ascorbic acid show little pH dependency, whereas reactions with gallic acid become much faster at increased pH. These dependencies correlate with the reductant ionization state, which affects its ability to react with mol. oxygen and generate H2O2. The correlation does not apply to L-cysteine because, as shown by stopped-flow kinetics, increased H2O2 prodn. at higher pH is counteracted by increased binding of L-cysteine to the copper active site. The findings highlight the importance of the choice of reductant and pH in LPMO reactions.
- 58Kommedal, E. G.; Angeltveit, C. F.; Klau, L. J.; Ayuso-Fernández, I.; Arstad, B.; Antonsen, S. G.; Stenstrøm, Y.; Ekeberg, D.; Gírio, F.; Carvalheiro, F.; Horn, S. J.; Aachmann, F. L.; Eijsink, V. G. H. Visible Light-Exposed Lignin Facilitates Cellulose Solubilization by Lytic Polysaccharide Monooxygenases. Nat. Commun. 2023, 14 (1), 1063, DOI: 10.1038/s41467-023-36660-4There is no corresponding record for this reference.
- 59Lu, X.; Gu, X.; Shi, Y. A Review on Lignin Antioxidants: Their Sources, Isolations, Antioxidant Activities and Various Applications. Int. J. Biol. Macromol. 2022, 210, 716– 741, DOI: 10.1016/j.ijbiomac.2022.04.22859https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xht1ant7fO&md5=839448455c38736db7a482f1d5feb23aA review on lignin antioxidants: Their sources, isolations, antioxidant activities and various applicationsLu, Xinyu; Gu, Xiaoli; Shi, YijunInternational Journal of Biological Macromolecules (2022), 210 (), 716-741CODEN: IJBMDR; ISSN:0141-8130. (Elsevier B.V.)A review. Lignin, a biopolymer obtained from agricultural/forestry residues or paper pulping wastewater, is rich in arom. structure, which is central to its adoption as a candidate to natural antioxidants. Through insight into its structural features from biomass, different functional groups would influence lignin antioxidant activity, wherein phenolic content is the most important factor, hence massive studies have focused on its improvement via different pretreatments and post-processing methods. Besides, lignin nanoparticles and chem. modifications are also efficient methods to improve antioxidant activity via increasing free content and decreasing bond dissocn. enthalpy of phenolic hydroxyl. Lignin samples exhibit comparable radicals scavenging ability to com. ones, showing their potential as renewable alternatives of synthesized antioxidants. Besides, their applications have also been discussed, which demonstrates lignin potential as an inexpensive antioxidant additive and consequent improvements on multiple functionalities. This review is dedicated to summarize lignin antioxidants extd. from biomass resources, methods to improve their antioxidant activity and their applications, which is beneficial for realizing lignin valorization.
- 60Gao, Z.; Lang, X.; Chen, S.; Zhao, C. Mini-Review on the Synthesis of Lignin-Based Phenolic Resin. Energy Fuels 2021, 35 (22), 18385– 18395, DOI: 10.1021/acs.energyfuels.1c0317760https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXisVagsr%252FJ&md5=c02ad6a5a8739c0c973b649c974d41c0Mini-Review on the Synthesis of Lignin-Based Phenolic ResinGao, Zhiwen; Lang, Xueling; Chen, Shuang; Zhao, ChenEnergy & Fuels (2021), 35 (22), 18385-18395CODEN: ENFUEM; ISSN:0887-0624. (American Chemical Society)A review. The use of biomass in phenolic resin can not only improve performance and reduce costs but can also reduce pollution and protect the environment. Lignin is a biopolymer with a three-dimensional network structure formed by three phenylpropane units of p-hydroxyphenyl, guaiacyl, and syringyl connected by an ether bond and carbon-carbon bond, contg. a large amt. of phenol or an aldehyde structure unit. It is an effective way to improve the economy, protect the environment, and reproduce the resin via the synthesis of high-performance biophenolic resin polymer materials by modification or depolymn. of lignin. This review describes the latest developments in the prepn. of phenolic resins by modification or depolymn. of lignin, focusing on the modification of its original functional groups by phenolization, demethylation, and hydroxymethylation, as well as chem. depolymn. methods. The properties of thermosetting or thermoplastic phenolic resins as prepd. by different lignin modification methods are compared, and the future research directions for the synthesis of biomass-based phenolic resins are prospected.
- 61Giummarella, N.; Lindén, P. A.; Areskogh, D.; Lawoko, M. Fractional Profiling of Kraft Lignin Structure: Unravelling Insights on Lignin Reaction Mechanisms. ACS Sustainable Chem. Eng. 2020, 8 (2), 1112– 1120, DOI: 10.1021/acssuschemeng.9b0602761https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXitl2lsr%252FL&md5=f69fc7cfba09bed2edb5a0c5f044a1d9Fractional Profiling of Kraft Lignin Structure: Unravelling Insights on Lignin Reaction MechanismsGiummarella, Nicola; Linden, Paer A.; Areskogh, Dimitri; Lawoko, MartinACS Sustainable Chemistry & Engineering (2020), 8 (2), 1112-1120CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)The kraft process is the main process used for the prodn. of chem. pulps. In this process, an efficient delignification is achieved, yielding bleachable grade pulps. In recent years, there has been interest in valorization of the dissolved lignins, prompted by the development of tech. feasible processes to retrieve it from the black liquor. However, the structural-, functional-, and size-related heterogeneities of lignin present both anal. challenges and challenges in developing new applications. Hence, refining of the crude product is essential. Herein, advanced NMR characterization (13C NMR, APT/DEPT NMR, 31P NMR, HSQC, HMBC, HSQC-TOCSY) was applied to profile the detailed mol. structures of refined kraft lignins and unravel mechanistic insights on important lignin reactions during kraft pulping. From this structural anal. of the lignins, a model oligomer was synthesized and analyzed to provide support to the effect that a retro-aldol reaction in combination with radical recombination reactions play a significant role in the formation of the reconstituted fraction of kraft lignin. In this regard, a new type of linkage accounting for approx. 10% of the interunits in kraft lignin is reported. Mol. structural studies corroborate that retro-aldol reaction followed by radical recombination is a crucial mechanism of lignin condensation during kraft pulping.
- 62Giummarella, N.; Pylypchuk, I. V.; Sevastyanova, O.; Lawoko, M. New Structures in Eucalyptus Kraft Lignin with Complex Mechanistic Implications. ACS Sustainable Chem. Eng. 2020, 8 (29), 10983– 10994, DOI: 10.1021/acssuschemeng.0c0377662https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXht1OhurjF&md5=e9ab3bc2f312cd632afdd7944d180456New Structures in Eucalyptus Kraft Lignin with Complex Mechanistic ImplicationsGiummarella, Nicola; Pylypchuk, Ievgen V.; Sevastyanova, Olena; Lawoko, MartinACS Sustainable Chemistry & Engineering (2020), 8 (29), 10983-10994CODEN: ASCECG; ISSN:2168-0485. (American Chemical Society)Recent years have seen the development of tech. feasible methods to retrieve kraft lignin from the black liquor as solids or liqs. This opens enormous opportunities to position kraft lignin as a renewable arom. polymer precursor. However, the heterogeneity of kraft lignin is one major hurdle and manifests in its largely unknown mol. structure, which in recent years has drawn further attention. In this context, we herein studied the detailed structure of Eucalyptus kraft lignin with special emphasis on identifying new linkages signatory to retro-aldol and subsequent radical coupling reactions, which we recently showed to be a key reaction sequence contributing to the structure of spruce kraft lignin. In combination with novel model studies, we unequivocally identified new structures by advanced 2D NMR characterization of Eucalyptus kraft lignin, i.e., 3,5-tetramethoxy-para-diphenol, 3-dimethoxy-para-diphenol and small amts. of 3,5-dimethoxy-benzoquinone. These structures are signatory to retro-aldol followed by radical coupling reactions. The two diphenol structures were further quantified by 1D 13C NMR at 9% of the interunit linkages in Eucalyptus kraft lignin, which was comparable to the amts. we previously identified in softwood kraft lignin (10%). Radical condensation of kraft lignin to form carbon-carbon bonds therefore does not discriminate between syringyl lignin and guaiacyl lignin units. We rationalize such indiscrimination to emanate from possibilities for radical couplings at unsubstituted C1 in the formed syringol and guaiacol lignin as a result of the retro-aldol reaction. Radical condensation of kraft lignin to form carbon-carbon bonds does not discriminate between syringyl lignin and guaiacyl lignin units.
- 63van Erven, G.; Boerkamp, V. J. P.; van Groenestijn, J. W.; Gosselink, R. J. A. Choline and Lactic Acid Covalently Incorporate into the Lignin Structure during Deep Eutectic Solvent Pulping. Green Chem. 2024, 26 (12), 7101– 7112, DOI: 10.1039/D4GC00909FThere is no corresponding record for this reference.
Supporting Information
Supporting Information
The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.biomac.4c01403.
Development of G. trabeum mycelium on wood blocks; mass loss of spruce and birch wood blocks; determination of lignin content; 13C-IS pyrolysis-GC-MS abundance of catechol/methoxycatechol pyrolysis products; aromatic regions of HSQC NMR spectra of sound and brown-rot decayed wood; quantitative 31P NMR spectra; SEC elution profiles; antioxidant capacity assay; relative mass of fractions after sequential solvent fractionation; HQSC NMR spectra of acetone/H2O extracts of brown-rot decayed wood; composition of carbohydrates, lignin, and protein in sound and brown-rot decayed wood; composition of structural carbohydrates in sound and brown-rot decayed wood; identity and structural classification of lignin-derived pyrolysis products detected; annotation of catechol and methoxycatechol pyrolysis products; molecular weight distribution of brown-rot decayed spruce and birch lignin isolates, and acetone/H2O extracts of these; structural characterization of acetone/H2O extracts of brown-rot decayed spruce and birch (PDF)
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