Synthesis, Characterization And DNA-binding Studies Of Complexes With Amino Acid Type Reduce Schiff Base Ligands

In this paper, we have reported the synthesis, characterization of fourteen Mannich ligands containing amino acid as a side chain and their binary,ternary copper(II) complexes. The DNA binding and cleavage properties and anticancer activities of some complexes were evaluated, they provided some useful information for the development of metal pharmaceutical chemistry. The dissertation includes following four chapters:In chapter one, we introduced the research progress in the copper(II) complexes of the Schiff bases and reduce Schiff bases, we also reviewed the research progress in the interactions of DNA with small molecules, the interaction mode and some of the influence factors. Further more, the aim and significance of this thesis have been outlined.In chapter two, eleven terephthalaldehyde,isophthalaldehyde benzene-1,3,5-tricarbaldehyde derivatives (H2L1-H2L11) and their ternary copper(II) complexes of N,N'-chelating ligands have been synthesized and characterized by elementary analyses, infrared spectra (IR) and some of them were characterized by single-crystal X-ray crystallography. We investigated the interactions of some of the complexes with DNA through various spectrophotometric methods and viscosity measurement, which suggested that the complexes can bind with DNA very efficiently. In addition, Comparative cytotoxic activities of the complexes were evaluated toward HeLa (Cervical cancer), HepG2 (hepatocarcinoma), HL-60 cells (myeloid leukemia), PC3 (human prostate), A-549 cells (pulmonary carcinoma) and L02 (liver cells) by acid phosphoatase assay (APA). The result suggested that they showed inhibitory effect against the six cell lines, along with facilitating the development of highly effective anti-cancer therapies. All the above complexes can cleavage pGL 4.20 DNA from supercoiled form to linear form by agarose gel electrophoresis study. Investigations of antioxidation properties show that all the copper(II) complexes have strong scavenging effects for hydroxyl radicals and superoxide radicals.In chapter three, two coumarin derivatives (H2L12-H2L13) and their ternary copper(II) complexes of phen have been synthesized and characterized by elementary analyses and infrared spectra (1R). The results from various spectrophotometric methods and viscosity measurement suggested that the complexes can bind with DNA very efficiently. In addition, Comparative cytotoxic activities of the complexes were evaluated toward HL-60 cells (myeloid leukemia), PC3 (human prostate) and L02 (liver cells) by acid phosphoatase assay (APA). The result suggested that they showed inhibitory effect against the three cell lines. All the above complexes can cleavage pGL 4.20 DNA from supercoiled form to linear form by agarose gel electrophoresis study, which is in line with the results of anti-cancer experiments.In chapter four, a salicyladehyde derivative (H3L14) and its copper(II) and zinc(II) complexes have been synthesized and characterized by elementary analyses, infrared spectra (IR) and single-crystal X-ray crystallography. In Zn(II) complex, the pentanuclear clusters formed by four H3Sas ligands and five Zn(II) metal ions are bridged by the "[Zn(H2O)4]2+" cations to form 1D polymeric chains. While in copper(II) complex, the mononuclear [Cu(HSas)(H2O)] repeating units form a 1D zigzag chain and further extended by strong intermolecular hydrogen bondings to form a 2D sheet. The different coordination geometries of Cu(II) and Zn(II) show significant influence on the polymeric structures.In chapter five, N,N',N"-tris(4-pyridinylmethyl)-1,3,5-benzene tricarboxa mide (L15) and its 2-D honeycomb structure of Cadmium(II) complex has been synthesized and characterized by elementary analyses, infrared spectra (IR) and single-crystal X-ray crystallography. Nearly perfectπ-πinteractions are found in this bilayer structure and This type of perfect face-to-faceπ-πinteractions are rare between benzene rings and its derivatives...