Antimicrobial activity of cobalst(II) complexes with 2-aminobenzimidazole derivatives

Abstract

Cobalt(II) chloride reacts with 2-aminobenzimidazole derivatives to give complexes of the formula [CoL2Cl2], where L=2-aminobenzimidazole 1-benzyl-2-aminobenzimidazole and 1-(4-methylbenzyl)-2-aminobenzimidazole. All the ligands and their cobalt(II) complexes were evaluated for their in vitro antimicrobial activity against Pseudomonas aeruginosa, Bacillus sp. Staphylococcus aureus, Sarcina lutea and Saccharomyces cerevisiae. The minimum inhibitory concentration (MIC) was determined for all ligands and their complexes. It was found that tested compounds were more active against gram-positive than gram-negative bacteria. None of the compounds were significantly effective against yeast Saccharomyces cerevisiae, except 2-aminobenzimidazole complex, which moderately inhibited the growth of yeast. 1-(4-methylbenzil)-2-aminobenzimidazole was found to be slightly active against Saccharomyces cerevisiae. The same ligand showed the lowest MIC value of 60 (g/ml against Pseudomonas aeruginosa, as well as 125 (g/ml, against Bacillus sp. and Sarcina lutea. The MIC value of its cobalt(II) complex was 60 (g/ml against Pseudomonas aeruginosa. Cobalt(II) complex with 1-benzyl-2-aminobenzimidazole showed the lowest MIC value of 60 (g/ml against Staphylococcus aureus. The effect of ligand and complex structure on the antimicrobial activity was discussed.

Keywords

• Benzimidazole
• complexes
• cobalt(II)
• antimicrobial activity
• in vitro studies