The Design And Investigation Of The Transition Metal Complexes With Biological Activities

The design and synthesis of chemical nuclease is the most attractive fields in the chemistry and biology over the last few decades. Focused on the top topic, phenolic hydroxyl Schiff base ligands and polypyridine derivatives have been used to design and synthesize thirty-two new complexes in this thesis. The structures of these complexes have been determined by X-ray crystallographic methods and characterized by element analyses and IR. We also investigated the interaction of these complexes with DNA by UV, fluorescent spectra, circular dichronism spectra, electrochemistry and gel electrophoresis. The main contributions in this work are below:1. We have synthesized five copper(II) complexes with phenolic hydroxyl Schiff base ligands. The magnetic property studies indicate that the existence of ferromagnetic coupling between the copper(II) ions in complex 1 and 4, and antiferromagnetic coupling in complex 3 and 5. In vitro DNA cleavage experiments show that complexes exhibit chemical nuclease activities in the presence or the absence of oxidant / reductant. The cleavage mechanisms between the complexes and plasmid DNA are likely to involve singlet oxygen ¹O₂ and·OH as reactive oxygen species.2. We have synthesized five cobalt and manganese complexes with phenolic hydroxyl Schiff base ligands and investigated the interactions with DNA. The results show that complexes exhibit chemical nuclease activities in the presence of H₂O₂ except complex 10. The cleavage mechanisms studies show that complexes may be capable of promoting DNA cleavage through an oxidative DNA damage pathway.3. Ten mononuclear complexes with phenolic hydroxyl Schiff base ligands have synthesized. The DNA cleavage results indicate that complexes exhibit chemical nuclease activities in the presence of H₂O₂ and cleavage mechanisms between the complexes and plasmid DNA are likely to involve singlet oxygen ¹O₂ and·OH as reactive oxygen species.4. Seven mononuclear complexes with polypyridine ligands have been synthesized and investigated the interactions with DNA.5. We have synthesized five copper(II) complexes with 1,10-phenanthroline-5,6-dione derivatives ligands. They are mononuclear complexes except 30 which is binuclear complex. The DNA cleavage results indicate that cleavage mechanisms between the complexes and plasmid DNA are likely to involve singlet oxygen ¹O₂ and·OH as reactive oxygen species. The magnetic property studies indicate that the existence of antiferromagnetic coupling between the copper(II) ions in complex 30.In this paper, we have researched the chemical nuclease activities of phenolic hydroxyl Schiff base and polypyridine derivatives transition metal complexes. All of these compounds will be beneficial for the designing chemical nuclease.