Anion effect on antimicrobial activity of metal complexes with benzimidazole derivative

Abstract

© 2017, CI and CEQ. All rights reserved. Chloride and nitrate of copper(ll) and zinc(ll) react with 1-(4-chiorobenzoyi)-2-methylbenzimidazole (L) to give complexes of the type ML2A2nH2O (M=Cu or Zn; A=Cl- or NO3-; n=0, 1 or 2). Ligand and its complexes were evaluated for their in vitro antimicrobial activity against three Gram-positive bacterial strains: Bacillus sp., Staphylococcus aureus and Sarcina lutea, one Gram-negative isolate: Pseudomonas aeruginosa and one yeast: Saccharomyces cerevisiae. The compounds were more active against Gram-positive than Gram-negative bacteria. None of the compounds were significantly effective against the yeast S. cerevisiae, except copper(ll) complex with chloride anion, which moderately inhibited the yeast growth. Zinc(ll) complex with chloride was found to be slightly active against Saccharomyces cerevisiae. The anion effect on antimicrobial activity of tested compounds was discussed. The minimum inhibitory concentration (MIC) was determined for the ligand and its complexes. The most active compound was copper(ll) complex with chloride anion. The MIC value of this complex was 60 µg/ml against Bacillus sp. and 125 µg/ml against S. aureus and S. lutea.