Green Chemistry approach for the synthesis of some Benzimidazole derivatives and their Biological Evaluation

Abstract

Microwave induced organic reactions are simple, fast, efficient and an economical method for the synthesis of organic molecules and has developed as a tool towards green chemistry. Microwave assistance can reduce the time of chemical reaction from hours to seconds. Benzimidazole nucleus owing to its wide range of biological activities anticipated to be an important pharmacophore in the modern drug discovery. Benzimidazole nucleus showing biological activities such as anti-convulsant, anti-inflammatory, anti-cancer etc., has made it an imperative anchor for development of modern therapeutic agents. Therefore six derivatives belonging to substituted benzimidazole were synthesized in one step microwave assistance and their structural integrity was confirmed by spectroscopy. The derivatives were evaluated in-vitro for free radical scavenging property, antimicrobial, cytotoxic activities. The free radical scavenging ability of synthesized compounds and standard ascorbic acid were tested using DPPH assay. The synthesized compounds 5(c), 5(d) and 5(f) possessed significant anti-oxidant property. The anti-microbial activity was assessed using two strains of gram positive and gram negative with standard tetracycline and the cytotoxic effect was performed using Brine shrimp lethality assay. Compounds 5(c), 5(d) and 5(f) showed significant anti-microbial action against gram positive and gram negative strains. LD50 was determined by cytotoxic assay using brine shrimp. Compounds 5(d) and 5(f) showed significant activity when compared with that of standard capacetabine. The results bespeak a new potential for benzimidazole derivatives as lead compounds to advance as medicinal agents.