Biological Evaluation of Novel 2-Benzimidazole Derivatives for Antibacterial Activity

Abstract Infectious diseases remain a persistent global health burden, with bacterial infections predominating. The growing global burden of drug-resistant infections has led to greater emphasis on the discovery and development of novel antibacterial compounds. In an attempt to discover new potent antibacterials, the antibacterial activity of novel 2-substituted benzimidazole derivatives (NR-1 to NR-9) was evaluated in this study against three bacteria, viz. M. smegmatis, B. subtilis and E. coli in vitro using Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Among the nine derivatives assessed, two (NR-4 and NR-5) exhibited inhibitory activity against M. smegmatis, while two (NR-5 and NR-7) were active against B. subtilis, with MICs between 62.5 and 250 μg/ml. Notably, NR-5 demonstrated antibacterial activity against both M. smegmatis and B. subtilis, with more efficacy against M. smegmatis (MIC: 62.5 μg/ml), which was considerably closer to rifampicin (MIC: 31.25 μg/ml). Cytotoxicity analysis of these derivatives in Vero cells indicated minimal toxicity for NR-4 and NR-5, and SwissADME evaluation suggested favourable physicochemical properties and drug-likeness, supporting good oral bioavailability. Moreover, the growth kinetics profiling of the NR-5 Benzimidazole derivative demonstrated that it inhibited the growth of M. smegmatis effectively, even after prolonged exposure. These findings highlighted the promise of the active benzimidazole derivative, NR-5, as a potential candidate for developing a more effective and less toxic antimycobacterial drug. Competing Interest Statement The authors have declared no competing interest.