DNA binding and nuclease activity of an oxovanadium valinato-Schiff base complex

A new oxovanadium complex [VO(sal-l-val)(phen)] (sal-l-val = Schiff base derived from salicylaldehyde and l-valine; phen = 1,10-phenanthroline) has been designed and synthesized with the aim of developing potential DNA nuclease. The interaction of DNA with this structurally characterized oxovanadium complex has been studied by various physicochemical tools like UV–vis, fluorescence, viscosity and circular dichroism (CD). The intrinsic binding constant of the complex with DNA is determined by electronic absorption studies and calculated to be (4.74 ± 0.02) × 105 M−1. The spectroscopic studies and the viscosity measurements indicate that the complex binds calf thymus DNA (CT-DNA) by intercalative mode. The ability of the complex to induce DNA cleavage was studied by gel electrophoresis techniques. The complex has been found to promote cleavage of pUC19 plasmid DNA from the super coiled (SC) form I to nicked coiled (NC) relaxed form II with good efficiency.