Antimicrobial, antioxidant and DNA interaction studies of water-soluble complexes of schiff base bearing morpholine moiety

Abstract

A novel series of metal (II) complexes, [CuL(AcO)].H2O (1), [CoL(AcO)].4H2O (2), [MnL(AcO)].4H2O (3), [NiL(AcO)].4H2O (4) and [ZnL(AcO)].2H2O (5) have been synthesized from 2-(2-morpholinoethylimino) methyl)phenol Schiff base ligand in a 1:1 molar ratio. The resulting compounds were characterized using various physical, chemical and spectral studies. The spectral results indicated square planar geometry around the metal (II) ion and found to possess [ML] stoichiometry. Complexes (1), (2) and (4) exhibited potent antimicrobial, antioxidant and DNA cleavage activities as compared to complexes (3) and (5). In vitro DNA binding properties of complexes (1-5) have been carried out employing the electronic absorption technique. The calculated intrinsic binding constant (Kb) values for the complexes were in the order of 1.3512×105 (1)>2.9843×104 (2)>1.6432×104 (4)>4.2280×103 (5)>2.9100×103 M−1 (3) and the DNA binding affinity values of the complexes obtained by the viscosity titration measurements were in the order of (1)>(2)>(4)>(5)>(3). The observed results suggested that the complexes (1-5) bind to DNA via intercalation.