Synthesis, Characterisation and Antimicrobial Studies of Metal(II) Complexes of Ofloxacin and Metronidazole

Abstract

Mixed ligands metal (II) complexes of Ofloxacin (OFL) and Metronidazole (MET) were synthesized and characterized by percentage metal analysis using complexometric titration method, infrared and electronic spectroscopies, magnetic susceptibility, melting points and conductance measurements. Infrared spectral data established that coordination was through OFL’s carboxy group oxygen and the pyridone carbonyl oxygen and MET’s imidazole nitrogen atom N and the hydroxyl oxygen atom of the terminal ethanol group. The magnetic susceptibility and electronic spectral data indicated that the metal (II) complexes have octahedral geometries while the low values of their molar conductance measurement suggest their non-electrolyte nature. The in-vitro antimicrobial studies were carried out against clinical strains of Staphylococcus aureus,  Enterotoxigenic Escherichia. coli, Enteropathogenic Escherichia. coli , Klebsiella pneumonia, Leclercia adecarboxylata, Morganella morganii,  Salmonella typhi and one fungus (Trichophyton rubrum) showed enhancement in antimicrobial activities of the free ligands through coordination to the metals as all the complexes exhibited better antimicrobial activities than the free ligands with the cobalt complex [Co(OFL)(MET)(H₂O)₂] showing the best activity at the concentration of 100 μg/ml.

Keywords: Antibiotics, Metronidazole, Microorganisms, Mixed ligands, Ofloxacin