Rhodanine-based biologically active molecules: synthesis, characterization, and biological evaluation

Abstract

To investigate the antimicrobial properties of the rhodanine (2-thioxo-4-thiazolidinone) structure, several 2-[(5Z)-5-benzylidene-4-oxo-2-thioxo-1,3-thiazolidin-3-yl]-N-phenylacetamide derivatives were synthesized by use of an efficient procedure. Variation of the functional group on the 5-benzylidine ring of rhodanine led to compounds containing a 2-thioxo-4-thiazolidinone group attached to N-phenyl acetamide. The chemical structures of the compounds were confirmed by IR, 1H NMR, and 13C NMR spectroscopy, ESI mass spectrometry, and elemental analysis. The antibacterial and antifungal activity of the compounds were tested, at seven concentrations, against Gram-positive bacterial strains (Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922), Gram-negative bacterial strains (Staphylococcus aureus ATCC 25923 and Bacillus subtilis ATCC 11774), and fungal strains (Candida albicans ATCC 66027 and Aspergillus niger ATCC 6275), by use of the Kirby Bauer disk-diffusion technique and the serial broth dilution technique. The results obtained were compared with those for reference drugs. Relationships between structure and their antimicrobial activity are discussed.