Anion effect on antimicrobial activity of metal complexes with benzimidazole derivative

Abstract

Chloride and nitrate of copper(II) and zinc(II) react with 1-(4-chlorobenzoyl)-2-methylbenzimidazole (L) to give complexes of the type ML2A2-nH2O (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(II) complex with chloride anion, which moderately inhibited the yeast growth. Zinc(II) 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(II) complex with chloride anion. The MIC value of this complex was 60 ?g/ml against Bacillus sp. and 125 ?g/ml against S. aureus and S. lutea.

Iron(III) and copper(II) complexes bearing 8-quinolinol with amino-acids mixed ligands: Synthesis, characterization and antibacterial investigation

“…The copper chelates system complex 4c was found to demonstrate higher inhibition (43 mm) at 10 ppm against P. aeruginosa compared with all other chelates, this may be attributed to the mobilized electron in the copper orbital as indicated by its magnetic property (Mwadham, 2013;Podunavac-Kuzmanovic, 2007;Patel et al, 2012). Presence of free electron in the Cu 2+ empowers its strong oxidative molecular activity for inhibitory ability on microorganisms as this re-emphasize the copper(II) ions as a key cofactor in a diverse array of biological oxidation-reduction reactions (Mwadham, 2013;Podunavac-Kuzmanovic, 2007;Jezowska, 2001;Jezowska et al, 1998;Solomon et al, 1996). …”

“…Interestingly, metal complexes of 8-hydroxyquinoline as a primary ligand can exhibit biological activity (Noorulla and Sreenivasulu, 2011;Singh et al, 2010;Freeman, 1973;Che and Siu, 2010;Podunavac-Kuzmanovic and Cvetkovic, 2007) and an amino acid as a secondary ligand were significant as potential model for enzyme metal ions substrate complexes (Patel et al, 2012). Literature survey to the best of our knowledge showed that our newly synthesized compounds inhibit the standard test microorganisms favourably (Patil, et al, 2012;Eddie et al, 2010;Khalil et al, 2010;Gaurav et al, 2011).…”

QSAR modeling of antibacterial activity of some benzimidazole derivatives

“…The position and type of the substituents on the benzimidazole ring are responsible for the variety of biological activities. Many derivatives of benzimidazole are well known as antibacterial agents, as well as this class of compounds have been found to show antimicrobial activities against Gram-positive and Gramnegative bacteria, primarily because of the potential bio-activity of benzimidazole-based ligands [8][9][10][11][12][13][14][15][16][17][18][19]. So, the incorporation of the imidazole and benzimidazole nuclei is an important synthetic strategy in drug discovery.…”

“…In view of the above and in continuation of our studies on inhibitory activities of benzimidazole derivatives [4][5][6][7], [11][12][13][14][15][16][17][18], as well as on correlation of molecular properties with activity, the objective of this investigation was to study the usefulness of QSAR in the prediction of the antibacterial activity of benzimidazole derivatives against Gram-negative bacteria Pseudomonas aeruginosa. The multiple linear regression (MLR) models have been developed as mathematical equations which relate chemical structure to the inhibitory activity.…”

Correlations between the lipophilicity and the inhibitory activity of different substituted benzimidazoles

“…Biologically active benzimidazoles have been known for a long time and they can act as bacteriostats or bactericides [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. The literature indicated that the benzimidazole nucleus is an essential part of many clinically useful chemotherapeutic agents.…”