Synthesis and antibacterial evaluation of furan derivatives bearing a rhodanine moiety

Two series of furan derivatives bearing a rhodanine moiety (4a-l and 5a-l) have been synthesized, characterized, and evaluated for their antibacterial activity. The majority of these compounds showed potent levels of inhibitory activity against a variety of different Gram-positive bacteria, including multidrug-resistant clinical isolates, with minimum inhibitory concentration (MIC) values in the range of 2-16 mu g/mL. In particular, compound 4l was found to be the most potent of the synthesized compounds against the multidrug-resistant strains, with a MIC value of 2 or 4 mu g/mL. None of the compounds exhibited any activity against the Gram-negative bacteria Escherichia coli 1356 at 64 mu g/mL. An examination of the cytotoxicities of these agents revealed that they displayed low levels of toxicity toward HeLa cells. All of the compounds synthesized in the current paper were characterized by H-1 and C-13 NMR, infrared, and mass spectroscopy.