Synthesis, physical properties, antimicrobial potentials of some antibiotics complexed with transition metals and their effects on alkaline phosphatase activities of selected rat tissues

Abstract

Metal complexes of ampicillin trihydrate, chloramphenicol and oxytetracycline with Ni(II), Fe(III) and
Co(II) chloride salts were prepared using standard methods. The geometry and the mode of binding of
complexes have been proposed on the basis of chemical analysis, conductivity measurements, molecular weight determinations and spectroscopic studies. Ampicillin and oxytetracycline coordinated
through the oxygen of the hydroxyl group and carbonyl group, and also through the nitrogen of the
lactam group and amide group, respectively, in the complexes. Chloramphenicol coordinated through
oxygen of the nitro group and carbonyl group and through nitrogen of the imines group in its mixed
complexes. Thus, the three ligands used acted as terdentate ligands. Antimicrobial properties as well
as the effect of administration of the metal complexes at the dose of 3.33 mg/kg body weight, thrice
daily for 5 days on the alkaline phosphatase (ALP) activities of rat kidney, liver and serum were
evaluated. Compared with their parent antibiotics, there was increase in the values of the physical
properties of the metal complexes. The zone of inhibition for Escherichia coli, Staphylococcus aureus
and Klebsiella pneumonia were significantly (P<0.05) increased by the complexes at the concentration
of 1% (w/v). ALP activities in the tissues were significantly (P<0.05) increased with no significant
change (P>0.05) in the serum enzyme. The results revealed more desirable physical properties and
enhanced antimicrobial activities upon complexation with the metal ligands. The increased ALP
activities in the tissues may have its consequential effect on the tissues.