Cu(ll) and Cd(ll) complexes containing 1, 10-Phenanthroline and Methylethylketone Thiosemicarbazone: synthesis, characterization and biological activity

Abstract

Methylethylketone thiosemicarbazone (MEKT) L₁ with 1,10-phenanthroline (Phen) L₂ reacted with Cu(II) and Cd(II) metal salts to obtain mixed-ligand complexes. These complexes were characterized by elemental analysis, FT-IR and UV-Vis spectroscopies. Elemental analysis results of the compounds were in good agreement with the theoretical values. FT-IR spectral data implied the ligand as a tridentate bonding ion through thioketo sulphur, azomethine nitrogen and pyridine nitrogen. The results of the evaluation of antibacterial activity showed that both complexes exhibited considerable activity against gram-positive (Staphylococcus aureus and Staphylococcus epidermides) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) pathogenic bacteria with both showing activity greater than that of the parent ligand MEKT. This implies that the ligand structural modifications accomplished enhanced the antibacterial activity of these compounds. Histopathological observation of the liver of wister rats treated with doses of 25 and 50 mg/kg body weight of MEKT and its Cu(II) and Cd(II) mixed-ligand complexes caused no observable variation when compared to the control group as cellular characteristics of lobular architecture were well preserved, normal hepatocytes, normal central vein and no indication of adhesion and no inflammatory cell infiltration an indication of little or no toxicity of the test drugs.

Keywords: Methylethylketone thiosemicarbazone, 1,10-phenanthroline, antibacterial activity, Histopathology