Human oxidation resistance 1 (OXR1) functions in protection against oxidative damage and its homologs are highly conserved in eukaryotes examined so far, but its function still remains uncertain. In this study, we identified a homolog (LMD-3) of human OXR1 in the nematode Caenorhabditis elegans (C. elegans). The expressed LMD-3 was able to suppress the mutator phenotypes of E. coli mutMmutY and mutT mutants. Purified LMD-3 did not have enzymatic activity against 8-oxoG, superoxide dismutase (SOD), or catalase activities. Interestingly, the expression of LMD-3 was able to suppress the methyl viologen or menadione sodium bisulfite-induced expression of soxS and sodA genes in E. coli. The sensitivity of the C. elegans lmd-3 mutant to oxidative and heat stress was markedly higher than that of the wild-type strain N2. These results suggest that LMD-3 protects cells against oxidative stress. Furthermore, we found that the lifespan of the C. elegans lmd-3 mutant was significantly reduced compared with that of the N2, which was resulted from the acceleration of aging. We further examined the effects of deletions in other oxidative defense genes on the properties of the lmd-3 mutant. The deletion of sod-2 and sod-3, which are mitochondrial SODs, extended the lifespan of the lmd-3 mutant. These results indicate that, in cooperation with mitochondrial SODs, LMD-3 contributes to the protection against oxidative stress and aging in C. elegans.
Side chain polyrotaxanes were synthesized from radically polymerizable pseudorotaxane monomers (DB24C8·1) which were composed of secondary ammonium salts having (meth)acryl group at one end and bulky stopper at the other end (1a and 1b) and dibenzo-24-crown-8 (DB24C8). Both radical polymerization of DB24C8·1 and copolymerization of DB24C8·1a with styrene afforded corresponding polymers having rotaxane moieties in the side chains (2a, 2b, and 3).
Conjugate addition of 4-tert-butylbenzenethiol to pseudorotaxane having terminal α,β-unsaturated ester group under radical condition afforded the corresponding aryl sulfide-capped rotaxane, while conjugate addition of sodium 4-tert-butylbenzenesulfinate under acidic condition also yielded aryl sulfone-capped rotaxane.
Treatment of 5‐acylamino‐6‐hydroxy (or benzoyloxy)methyl‐3‐phenylpyrimidin‐4(3H)‐one 5,10 with 5% aqueous sodium hydroxide in ethanol gave 2‐alkyl‐5‐hydroxymethyl‐4‐phenylcarbamoyl‐1H‐imidazoles 7,11. Oxidation of 5‐amino‐6‐benzoyloxymethyl‐3‐phenylpyrimidin‐4(3H)‐one 9 in the presence of copper(II) chloride in alcohol gave 2‐alkoxy‐5‐alkoxymethyl‐4‐phenylcarbamoyl‐1H‐imidazoles 12a,b accompanied by 5‐amino‐6‐alkoxymethyl‐3‐phenylpyrimidin‐4(3H)‐ones 13a,b.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.