SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL ACTIVITIES OF SCHIFF BASE METAL (II) COMPLEXES DERIVED FROM L-METHIONINE AND CUMINALDEHYDE

Abstract

Schiff bases are one of the important class of organic ligands, which are obtained by the condensation of aldehydes/ ketones with primary amines. The metal complexes of Schiff bases are widely studied because they possess very good biological applications such as antimicrobial, larvicidal, antioxidant, antitubercular, antidiabetic, anti-inflammatory and antitumour properties. The present work deals with synthesis and characterization of a series of Schiff base transition metal complexes obtained from amino acid with general formula [ML1 L 2 ](ClO4 ) [where, M = Co2+, Cu2+, Ni2+ and Zn2+ ; L 1 = Schiff base ligand derived from L-methionine and cuminaldehyde; L2 = N,N,N’,N’-tetramethyl-1,3- diaminopropane]. The synthesised complexes were characterized by physicochemical and spectral analyses such as UVVis., FTIR, GC-MS and ESR. They were also tested for in vitro biological activities. The FTIR spectra confirmed the bidentate coordination nature of the Schiff base via imine nitrogen and one of the oxygen atom of carboxylate group. The in vitro antibacterial studies were carried out against S. Aureus, E. Coli, P. aeruginosa, Bascillus as well as antifungal studies against A. flavus, Candida, Rhizhopus and A. Niger. Larvicidal activity was performed against Culex quinquefasciatus and antioxidant activity of the complexes was studied by H2O2 and DPPH method. The results proved that the complexes have good biological activities.