A Platform for the Development of Highly Red-Shifted Azobenzene-Based Optical Tools.

Azobenzenes are versatile photoswitches that can be used to generate elaborate optical tools, including photopharmaceuticals. However, the targeted application-guided design of new photoswitches with specific properties remains challenging. We have developed synthetic protocols for derivatives of the dfdc (di-ortho-fluoro-di-ortho-chloro) azobenzene scaffold with chemical alterations in the para-/ortho-positions and performed an in-depth study into the effects of their structures on their photophysical properties with an emphasis on the n → π* absorption band using NMR, UV-vis, and X-ray analysis.

Enhancing cellular sulfane sulfur through β-glycosidase-activated persulfide donors: mechanistic insights and oxidative stress mitigation.

Sulfane sulfur species such as persulfides and polysulfides along with hydrogen sulfide protect cells from oxidative stress and are key members of the cellular antioxidant pool. Here, we report perthiocarbamate-based prodrugs that are cleaved by β-glycosidases to produce persulfide and relatively innocuous byproducts. The β-glucosidase-activated persulfide donor enhances cellular sulfane sulfur and protects cells against lethality induced by elevated reactive oxygen species (ROS).

CobT and BzaC catalyze the regiospecific activation and methylation of the 5-hydroxybenzimidazole lower ligand in anaerobic cobamide biosynthesis.

Vitamin B and other cobamides are essential cofactors required by many organisms and are synthesized by a subset of prokaryotes via distinct aerobic and anaerobic routes. The anaerobic biosynthesis of 5,6-dimethylbenzimidazole (DMB), the lower ligand of vitamin B, involves five reactions catalyzed by the operon gene products, namely the hydroxybenzimidazole synthase BzaAB/BzaF, phosphoribosyltransferase CobT, and three methyltransferases, BzaC, BzaD, and BzaE, that conduct three distinct methylation steps. Of these, the methyltransferases that contribute to benzimidazole lower ligand diversity in cobamides remain to be characterized, and the precise role of the operon protein CobT is unclear.