Synthesis,DNA-binding,cytotoxicity and cleavage studies of unsymmetrical oxovanadium complexes

An unsymmetrical oxovanadium complex [VO(SAA)(phen) ](1),(SAA = salicylidene anthranilic acid,phen = phenanthroline) and its novel derivatives [VO(MOSAA)(phen) ](2)(MOSAA = 2-hydroxy-4-methoxysalicylidene anthranilic) have been synthesized and characterized by elemental analysis,UV-Vis,ES-MS,IR and 1 H NMR.The interaction of these two complexes with CT-DNA was investigated by absorption titration,fluorescence spectra,viscosity measurements and thermal denaturation.Their photocleavage reactions with pBR322 supercoiled plasmid DNA were investigated by gel electrophoresis experiments.The cytotoxicity of these two complexes against Myeloma cell(Ag8.653) and Gliomas cell(U251) have been assessed by MTT assay.The experimental results show that both complexes 1 and 2 bind to CT-DNA in classical intercalation mode,and the DNA-binding affinity of the complex 1 is larger than that of complex 2.It is interesting to note that these two complexes prominently enhance the oxidative cleavage of supercoiled pBR322 DNA and both complexes present cytotoxic activities against Ag8.653 and U251 cell lines.Complex 1 possessed the more potent inhibitory effect against the two cell lines of the two complexes.