Synthesis, characterization and antimicrobial activity of mixed ascorbic acid - nicotinamide metal complexes

Abstract

The present study aimed at synthesizing copper(II) and zinc(II) complexes of mixed ascorbic acid and  nicotinamide and physiochemically characterize by solubility test, melting point, conductivity test, infrared, electronic and proton nuclear magnetic resonance techniques. The result of the physiochemical studies indicated 1:1 stoichiometry and were supported by the spectroscopic data. The antimicrobial activities of the mixed complexes were carried out against Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Penicillum, spp Aspergillus flavus and Aspergillus niger. The result of the infrared data showed that ascorbic acid coordinates through the oxygen of the carbonyl group and that of enolic C-2 hydroxyl group, while nicotinamide coordinates through the nitrogen atom of the pyridine ring. The result of the antimicrobial studies showed that the mixed complexes have higher inhibitory activity than the original ligands against the tested bacteria and fungi species.

KEY WORDS: Ascorbic acid, Nicotinamide, Synthesis, Antimicrobial, Complexes.