Catechol-bearing imidazolium and benzimidazolium chlorides as promising antimicrobial agents.

Catechol-containing imidazolium (four) and benzimidazolium chlorides (eight) were synthesized to evaluate their antimicrobial properties. All the compounds were fully characterized using H and C nuclear magnetic resonance, liquid chromatography-mass spectrometry, infrared spectroscopic methods, and elemental analyses. Antimicrobial activities of the compounds were tested against the bacteria Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Enterococcus faecalis, and the fungal strains Candida albicans and Candida glabrata, and promising results were achieved. The two most important benzyl-substituted benzimidazolium chlorides, 3l and 3k, showed comparable activity to vancomycin against MRSA.