Synthesis, antimicrobial activity and cytotoxicity of 2-substituted benzimidazole incorporated with thiazole

Abstract

Two new series 2-(2-(1-(1-methyl-1H-benzo[d]imidazol-2-yl)ethylidene)hydrazinyl)-4-(aryl)thiazoles 3a-k and 2-(2-(1-(1-methyl-1H-benzo[d]imidazol-2-yl)ethyl)hydrazinyl)-4-(aryl)thiazoles 4a-k encompassing benzimidazole incorporated with thiazole have been synthesized using rational approach. These thiazole derivatives 3a-k have been reduced at the site of formation of Schiff base (>CH=N-) to obtain final compounds 4a-k. Compounds 3a-k and 4a-k have been screened for their in vitro antibacterial and antifungal actions against four strains each. Among the screened compounds, 3d, 3e, 3f, 3g, 3j, 3k, 4d, 4e, 4f and 4k have emerged as highly effective antibacterial agents, while compounds 3d, 3e, 3f, 3k and 4k have come out as most potent antifungal molecules. Comparison of outcomes of antibacterial and antifungal screening of compounds 3a-k and 4a-k directed that antimicrobial potential of unreduced derivatives 3a-k is higher than reduced derivatives 4a-k. SAR study reveals that presence of halogen (-F, -Cl, -Br) substituents is accountable for significant antimicrobial potential. Also the results of preliminary MTT cytotoxicity assay on HeLa cells indicates that antimicrobial activity of 3e, 3f, 3g, 3j, 3k, 4e, 4f and 4k is accompanied by low extent of cytotoxic concentrations.