Synthesis, antimicrobial evaluation, and molecular docking study of fenchol- and menthol-based derivatives

A new series of substituted heterocyclic compounds was synthesized through the reaction of cyanoacetyl derivatives 3a,b with various reagents, including substituted aldehydes 4a–e, aryl diazonium salts 7a–b, 2-cyano-3-(5-methylfuran-2-yl)acrylic acid ethyl ester 11a, and 2-(5-methylfuran-2-ylmethylene)malononitrile 11b under basic condition. The structures of the obtained compounds were confirmed by elemental and spectral analyses. Additionally, the mechanisms of their formation were considered. The antimicrobial activities of the synthesized compounds were evaluated against six microbial strains, including Gram-positive and Gram-negative bacteria as well as fungi. The tested compounds exhibited different degrees of antibacterial activity compared with the standard drugs. Compounds 3b and 10b displayed broad-spectrum activity, with compound 10b showing the highest efficacy; its inhibition zones were nearly twice those of the reference drugs. In silico molecular docking analyses of compounds 10a and 10b revealed comparable binding affinities toward Escherichia coli DNA gyrase B.