Antimicrobial activity of Fe-III, Cu-II, Ag-I, Zn-II and Hg-II complexes of 2-(2-hydroxy-5-bromo/nitro-phenyl)-1H- and 2-(2-hydroxyphenyl)-5-methyl/chloro/nitro-1H benzimidazoles

Abstract

Antimicrobial activity of 2-(2-hydroxyphenyl)-5-R-5-1H-benzimidazoles, 2-(2-hydroxy5-R-5'-phenyl)-1H-benzimidazoles and their Fe-III, Cu-II, Ag-I, Zn-II and Hg-II nitrate complexes was tested toward Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneunioniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella flaxneri, and Proteus mirabilis. Antifungal activity was tested against Candida albicans. Benzimidazole benzene ring substituents increase the antimicrobial activity, phenol ring substituents decrease it. The ligands show an antibacterial effect against only S. aureus whereas Ag-I and Hg-II complexes of the ligands have a higher activity with respect to the other complexes to all the bacteria. On the other hand, Fe-III complexes show a considerable activity against S. aureus and S. epidermidis.