Antioxidant Activity, Synthesis and Characterization of Schiff Base Ligand 'asasp' and Metal Complexes

摘要

In the present work, the synthesis and structural characterization of a novel Schiff base ligand derived from 2-acetyl pyridine and L-aspattic acid dimethyl ester and its metal complexes have been reported. All the synthesized compounds were characterized by using various spectral techniques like ESI-MS, FT-IR, ~1H NMR, ~(13)C NMR, UV-visible spectra, elemental analysis and ICP-OES analyses. The ligand and metal ions reacted to form in the 2:1 or 1:1 (M:L) ratio as found from the elemental analyses and the general stoichiometry was determined [L(Cu)2(AcO)4] and [LM(H2O)2]2Cl·nH2O where M = Co(II), Ni(II), Ni(II) and L = asasp and n = 1 or 2. On the basis of analytical data, a possible structure for the copper(II) complex is tetrahedral and those for the Co(II), Ni(II) and Mn(II) complexes are octahedral. The ligand and its metal complexes were tested for their possible antioxidant potentials. Comparison of antioxidant assays were investigated by using two reference molecules, vitamin C and quercetin. The complexes showed significant activities in these in vitro antioxidant assays compared to the reference (quercetin and vitamin C) and Ni(II)-complex exhibited a promising antioxidant activity.