Synthesis Of Benzocrown Ether-functionalized Cyclen Compound And DNA Cleavage By Their Metal Complexes

The macrocyclic polyamines are a kind of excellent ligands and have a substantially high binding affinity with transition metal ions. Macrocyclic polyamine metal complexes are widely used in chemical biology, medicine and gene therapy. Artificial enzymes, which selectively cleavage DNA at the target position with a desired specificity, are very important. 1, 4, 7, 10-tetrazacyclododecane (cyclen) is a representative compound in macrocyclic polyamine family. Many metal cyclen complexes have been prepared and used in DNA recognition and cleavage as chemical nucleases.In this thesis, the synthesis, characteristics of a series of mononuclear zinc (II), copper (II), cobalt (II) complexes of crown ether-functionalized cyclen ligand were described. The interaction between the complexes and plasmid DNA were studied. The results showed that the copper (II) complex displayed higher catalytic ability than that of zinc (II) and cobalt (II) complexes. The effects of reaction time, concentration of complexes were also investigated, and the results indicated that the copper (II) complexes could catalyze the cleavage of supercoiled DNA ( pUC 19 plasmid DNA ) ( Form I ) under physiological conditions to produce nicked DNA ( Form II, no Form III produced ) selectively with high yields. The primary investigation of the cleavage process reveals that it might be an oxidative mechanism.