Synthesis, biological evaluation and molecular docking studies of novel 1,8-naphthyridine-3-carboxylic acid derivatives as potential antimicrobial agents (part-1)

Abstract

Synthesis and investigation of antimicrobial activity of 6 novel 1,8-naphthyridine-3-carboxylic acid derivatives are presented. Among the derivatives, compounds 4a-5b2 showed a broad-spectrum antimicrobial activity against all reference Gram-positive, Gram-negative bacteria and fungi. These compounds exhibited remarkable bactericidal activity against Staphylococcus and Bacillus sps. The tested substances 4a-5b2 were found also found to be active against Escherichia coli, Salmonella and Shigella sps. The chlorine substituted compounds 4a and 5a2 were found to be the most active towards the tested microorganisms. Compounds 4a-5b2 were found to be fungicidal against Candida sp. with a MIC values in the range of 400-2000 μg/ml. Docking studies of these compounds with Salmonella typhi OmpF complexed with ciprofloxacin using PDB-4KRA revealed that the compounds acted as covalent crosslinker on the DNA gyrase B of the former and intercalate the latter both with higher C score values. Thus, the antibacterial activity against tested strains suggested 1,8-naphthyridine-3-carboxylic acid derivatives warrant further evaluation as potential novel antiinfective agents. The antifungal activity of these compounds was comparable to that of griseofulvin. The drug-likeness data of synthesized compounds made them promising leads for the future development as antifungal agents.