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.Kobalt(II)-hlorid reaguje sa derivatima 2-aminobenzimidazola dajuci komplekse tipa [CoL2Cl2] (L=2-aminobenzimidazol 1-benzil-2-aminobenzimidazol i 1-(4-metilbenzil)-2-aminobenzimidazol). Ispitana je antimikrobna aktivnost liganada i njihovih kompleksa sa kobaltom na Pseudomonas aeruginosa, Bacillus sp., Staphylococcus aureus, Sarcina lutea i Saccharomyces cerevisiae. Za sve ligande i njihove komplekse odredjena je minimalna inhibitorna koncentracija (MIK). Ispitivana jedinjenja pokazuju vecu inhibitornu aktivnost prema gram-pozitivnim, nego prema gram-negativnim bakterijama. Nijedno od ispitivanih jedinjenja, izuzev 2-aminobenzimidazola ne pokazuje znacajniju aktivnost na rast kvasca Saccharomyces cerevisiae. 1-(4-metilbenzil)-2-aminobenzimidazol pokazuje veoma slab inhibitorni efekat na kvasac. Za Pseudomonas aeruginosa najnizu MIK vrednost imaju 1-(4-metilbenzil)-2-aminobenzimidazol i njegov kompleks i ona iznosi 60 (g/ml. MIK za Bacillus sp.i Sarcina lutea je takodje najniza za 1-(4-metilbenzil)-2-aminobenzimidazol i iznosi 125 (g/ml. Za bakteriju Staphylococcus aureus najniza MIK je 60 (g/ml i karakteristicna je za kompleks kobalta(II) sa 1-benzil-2-aminobenzimidazolom. Diskutovan je uticaj strukture liganda i kompleksa na njihovu antimikrobnu aktivnost.