Abstract

SYNTHESIS AND INVESTIGATION OF BIOLOGICAL PROPERTIES OF THE 2-SUBSTITUTED BENZIMIDAZOLE DERIVATIVES

Mamun Sarker*, Md. Nurnabi and Md. Rafiqul Islam

Abstract

2-(3-cyano-phenyl)-1H-Benzimidazole [MCB], 2-(4-hydroxy-phenyl)-1H-Benzimidazole [MHB] and 2-(4-nitro-phenyl)-1H-Benzimidazole [MNB] were synthesized from o-phenylene diamine and different aldehydes to investigate the biological (i.e. antimicrobial and cytotoxicity) studies as 2-substituted benzimidazole derivatives have promising biological activities. The structures of the synthesized molecules were confirmed through analysis of FTIR, 1H-NMR, 13C-NMR, and 13C-DEPT NMR spectra. In-vitro antibacterial assay was studied against both gram-positive and gram-negative bacterial strains. B. subtilis was the most susceptible bacteria against all the synthesized benzimidazole derivatives under investigation. MNB showed highest antibacterial activity in contrast to MHB & MCB whereas MCB showed least activity. A. niger was the resistant fungal strains to all the test materials under analysis. In term of cytotoxicity based on the brine shrimp lethality bioassay, MNB showed highest toxicity (lowest LC50 value, 6.13 μg/mL) while MHB reflected least toxicity (LC50 value, 28.18 μg/mL).

Keywords: 2-substituted benzimidazole derivatives, antimicrobial activity, cytotoxicity, LC50 value.