新型含氧钒配合物的合成 表征及其与dna相互作用的分析-synthesis and characterization of novel vanadic complex and analysis of its interaction with dna.docxVIP

present dissertation, a series of novel oxovanadium complexes with small molecular weight have been synthesized and characterized. Their binding modes and binding affinities with calf thymus DNA (CT-DNA) have been studied in principal. The photocleavage activities of some oxovanadium complexes towards PBR322 DNA have been tested as well. Besides, preliminary researches on the in vitro scavenging activities of these oxovanadium complexes against hydroxyl radicals have been conducted. The principal contents of my research include:Six novel oxovanadium complexes incorporating Schiff bases, namely salicylaldehyde thiosemicarbazones as well as their derivatives, as primary ligands and the phenanthroline or bipyridine as auxiliary ligands were synthesized and characterized by elemental analysis, UV-Vis, ES-MS and 1H NMR.The binding modes as well as binding strength of these complexes withCT-DNA were studied using electronic absorption titration, fluorescence spectra, viscosity measurements, circular dichroism and thermal denaturation. The magnitude of their binding strength with CT-DNA was also elucidated from electronic effects as well as the size of aromatic conjugated system. The experimental results indicate that the binding affinity of oxovanadium complexes bearing aromatic chromophores with no groups was larger than that of those with electron-withdrawing groups substituted such as Cl, Br and so on. Meanwhile, the binding strength of oxovanadium complexes bearing phenanthroline as the auxiliary ligand was larger than that of those bearing bipyridine as the auxiliary ligand.The photocleavage efficiency of two oxovanadium complexes exhibiting stronger binding affinity with CT-DNA among all the vanadyl complexes was tested. It was found that two oxovanadium complexes, VO(s)(p) and VO(s)(b), could catalyze the photocleavage of plasmid pBR322 DNA and the photocleavage efficiency of VO(s)(p) was better than that of VO(s)(b).Using safranin as a substrate, the scavenging ac