Synthesis Of Cyclotetraphosphazene Polydentate Ligands And Their DNA Cleavage Activity

Artificial nucleases have recently received considerable interest for their potential applications in molecular biological technology and drug development, at the same time it is an important tool in the fields of molecular biology and genetic engineering. Artificial nuclease is used as a kind of nucleic acid structure and function probe, Hence, finding out highly efficient artificial nuclease reagent is very important, especially cleavage reagent in a sequence-specific way.In the last several years, many complexes have been developed as artificial enzyme.Among these systems, multi-nuclear complexes are particular attractive due to their potential cooperative effects between the metal centers.Herein, In this dissertation, series of cyclotetraphosphazene polydentate ligands were designed and synthesized containing different heterocyclic (morphoine,imidazole).These target compounds were characterized by 1H NMR,31P NMR,13C NMR,IR and ESI-MS.The intetaction of plasmid pUC19 DNA and CtDNA with ligands in the presence of Cu(â…¡),Zn(â…¡),Co(â…¡) complexes respectively was monitored by Agarose gel electrophoresis and UV-Visible.The experimental results show that:octa-nuclear was indicated superior reactivity comparing to the hexa-nuclear.Their cleavage and mechanism is free radical oxidation of cutting;They are six-and eight-coordinated ligand Separately;And the six ligands in the study,the eight-coordination of the Zn complex spectral changes of the greatest interaction with CtDNA also the strongest, and the inferred mode of action may be part of the intercalative CtDNA of base pairs.