Identification of a Novel Series of N ‐ P henyl‐5‐[(2‐phenylbenzimidazol‐1‐yl)methyl]‐1,3,4‐oxadiazol‐2‐amines as Potent Antioxidants and Radical Scavengers

In this study, some novel 5‐[[2‐(phenyl/ p ‐chlorophenyl)‐benzimidazol‐1‐yl]‐methyl]‐ N ‐substituted phenyl‐1,3,4‐oxadiazol‐2‐amine derivatives ( 28 – 45 ) with an oxadiazole ring were synthesized. The antioxidant properties and radical scavenging activities of the compounds were investigated employing various in vitro systems: hepatic microsomal NADPH‐dependent inhibition of lipid peroxidation levels, scavenging of DPPH free radicals, and inhibition of microsomal ethoxyresorufin O ‐deethylase activity (EROD). Compounds 34 and 41 were found to be good scavengers of DPPH radicals (76% and 84%) when compared to BHT (90%). Almost all of the compounds examined were found to possess a good inhibitor effect on the microsomal EROD activity. Moreover, 32 and 41 were more active analogs (97% and 98%) on the microsomal EROD activity than caffeine (85%).