Synthesis of pyridyl benzimidazoles encompassing 4-thiazolidinone derivatives as potential antimicrobial agents

Present article deals with the synthesis and antimicrobial screening of a series of novel 6-(1H-benzo[d]imidazol-2-yl)-2-(2-(3-hydroxyphenyl)-4-oxothiazolidin-3-yl)-4-(aryl)-nicotino- nitriles (6a-p) and structures of these compounds were elucidated by IR, 1H NMR, 13C NMR and mass spectrometry techniques. The newly synthesized compounds were evaluated for their in vitro antibacterial activity against Gram-positive (Staphylococcus aureus, Streptococcus pyogenes), Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria and fungal (Candida albicans, Aspergillus niger, Aspergillus clavatus) strains using serial broth dilution method. Among the synthesized compounds, 6m emerged as a most potent antibacterial while 6n indicated as a most active antifungal agents. From the standpoint of SAR studies, it was observed that presence of electron donating groups remarkably enhanced the antimicrobial activity of newly synthesized compounds. Further, the results of preliminary MTT cytotoxicity studies on HeLa cells suggested that potent active compounds 6e-6g and 6j-6n is associated with low level of cytotoxicity.