N-Aryl-3-mercaptosuccinimides as Antivirulence Agents Targeting Pseudomonas aeruginosa Elastase and Clostridium Collagenases

In light of the global antimicrobial-resistance crisis, there is an urgent need for novel bacterial targets and antibiotics with novel modes of action. It has been shown that Pseudomonas aeruginosa elastase (LasB) and Clostridium histolyticum (Hathewaya histolytica) collagenase (ColH) play a significant role in the infection process and thereby represent promising antivirulence targets. Here, we report novel N-aryl-3-mercaptosuccinimide inhibitors that target both LasB and ColH, displaying potent activities in vitro and high selectivity for the bacterial over human metalloproteases. Additionally, the inhibitors demonstrate no signs of cytotoxicity against selected human cell lines and in a zebrafish embryo toxicity model. Furthermore, the most active ColH inhibitor shows a significant reduction of collagen degradation in an ex vivo pig-skin model.

S5 Figure S3. Calibration curve of hydroxyproline. Mean ± SD of three independent measurements are depicted.

General procedure F: Thioacetate hydrolysis to obtain compounds 47-49
Thioacetate (1.0 eq) was dissolved in methanol under Ar atmosphere, and 2 M aqueous solution of NaOH (2.0-3.0 eq) was added. The reaction was stirred 1-2 h at r.t. After quenching with 1M HCl, the reaction was extracted 3 times with EtOAc. Combined organic extracts were washed with brine and dried over anh. Na2SO4, filtered and the solvent was removed under reduced pressure. The crude product was purified using column chromatography or used in the next step without further purification.
Compound 39 was obtained as yellow solid (301.2 mg, 39%), while corresponding citraconimide was not isolated in this case. 1 H NMR and 13 C NMR are in accordance with the spectra from the literature. 2

S22
Screening of compounds for PAINS and prediction of BBB penetration. Table S2. Results of the screening using StarDrop software.
Results for PAINS are given as a number of functional groups counted as PAINS. Positive controls: atovaquone (53) and zuclopenthixol (54).
BBBlog states for the partition coefficient between brain and blood. BBB category separates compounds into CNS active (+) and inactive (-).