SYNTHESIS, CHARACTERIZATION, ANTI-OXIDANT ACTIVITIES OF SCHIFF BASE, ITS METAL COMPLEXES AND ITS ASSESSMENT AS AN ANTIMICROBIAL AGENT AGAINST DIFFERENT PATHOGENIC MICROBES

Abstract

A novelSchiff base ligand, (Z)-3-((2-(4-methyl-2,5-dinitrophenyl) hydrazineylidene)methyl)pyridine]was synthesized via the condensation of 2,4-dinitrophenylhydrazine with pyridine-3-aldehyde. Transition metal chloride salts of copper (Cu) and cobalt (Co), both in the (II) oxidation state, were employed to form coordination complexes with the synthesized Schiff base. The metal-to-ligand ratio for all complexes was determined to be 1:2, with the general molecular formula represented as ML₂ M(C₁₃H₁₁N₅O₄)₂), where M denotes either Cu (II) or Co (II) and L denotes Schiff base ligand. In the present casethe molecular formula of the Schiff base ligand wasC₁₃H₁₁N₅O₄.

The synthesized ligand and its metal complexes were characterized using Fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (¹H NMR) to confirm their structural composition. Biological activities including antimicrobial and antioxidant properties were evaluated to assess the potential applications of these compounds in pharmaceutical and biomedical fields.

Four bacterial strains namely:E. coli, E. bacelisa, B.Subtilis, A. bacter, S.typhi and C. bacterwere used to determine the antibacterial efficiency of the Schiff base ligand and its ML₂ complexes. Antibacterial activity was assessed using the disk diffusion method, and the results indicated notable inhibitory effects. Similarly, antifungal activity was evaluated using four fungal strainsCandida albicans, Aspergillus niger, Aspergillus flavus, and Trichoderma viride. The results demonstrated impressive antifungal activity for the synthesized complexes, indicating their potential as antifungal agents.

Additionally, the antioxidant activity of the synthesized compounds was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. The results suggested that the antioxidant properties of the synthesized samples were remarkable, further highlighting the potential of these compounds for use in biological applications.

In conclusion, the synthesized Schiff base ligand and its metal complexes with Cu(II) and Co(II) exhibit promising antibacterial, antifungal, and antioxidant properties, making them suitable candidates for further exploration in biomedical and pharmaceutical applications.