Oxovanadium Complexes with Bidentate N, O Ligands: Synthesis,Characterization, DNA Binding, Nuclease Activity and Antimicrobial Studies

Abstract

Novel oxovanadium(IV) complexes (1-4) with 2-methyl-3-(pyridine-2-ylmethyleneamino)quinazolin-4(3H)-one (L1) or3-(2-hydroxy-3-methoxybenzylideneamino)-2-methylquinolin-4(3H)-one (L2) were synthesized and characterized by elemental analysis, IR, 1H-NMR, electronic spectra, molar conductance and thermal studies. Based on the above spectral studies, the complexes have the general formula [VO(L1)2] (1), [VO(L1)phen] (2), [VO(L2)2] (3) and [VO(L2)phen] (4). The synthesized compounds were tested for antimicrobial activity by disc diffusion method. The results indicate the enhanced activity of metal complexes over their parent ligands. The DNA binding and nuclease activity of the synthesized compounds were also studied. The investigation of the interaction of the complexes with calf thymus DNA has been performed with absorption spectroscopy which showed that the complexes are avid binders of calf thymus DNA. Also, the interaction of the oxovanadium(IV) complexes with plasmid DNA (pUC 19) was studied using agarose gel electrophoresis. The results revealed that these complexes could act as effective DNA cleaving agents resulting in the nicked form of DNA (PUC 19) under physiological conditions. The gel was run both in the absence and in presence of the oxidizing agent.