Synthesis, Characterization, And DNA-binding Study On The Ethoxy Chromone Schiff-base Metal Complexes

In this paper,we have reported synthesis and characterization of flavonoids Schiff-bases complexes,and studied their biological activities.Four kinds of flavonoids Schiff-bases and their fourteen complexes have been synthesized.This paper is composed of six chapters:In the first chapter,we summarize progress in pharmacological research of flavonoids and interactions of metal complexes with DNA-binding.In the second chapter,a 6-ethoxy chromone-3-carbaldehyde benzoyl hydrazone ligand(HL¹) and its Ln(â…¢) complexes,(Ln=Sm,Eu,Gd,Tb) have been prepared and characterized.The fluorescent properties of the Eu(â…¢) and Sm(â…¢) were studied. All the experimental evidences indicate that the complexes can bind to ct-DNA via an intercalation mechanism.Furthermore,antioxidant activity tests in vitro showed that the Ln(â…¢) complexes have significant antioxidative activity against hydroxyl free radicals from the Fenton reaction.In the third chapter,a 6-ethoxy chromone-3-carbaldehyde benzoyl hydrazone ligand(HL¹) and its transition complexes(Zn and Ni) have been prepared and characterized.The Zn(â…¡) complex exhibits light blue fluorescence under UV light,the fluorescent properties of the ligand and the complex in solid state and in different solutions are investigated.All the experimental evidences indicate that the ligand and the complexes can bind to ct-DNA via an intercalation mechanism.In the fourth chapter,a 6-ethoxy chromone-3-carbaldehyde 4-hydroxy-benzoyl hydrazone ligand(H₂L²) and its Ln(â…¢) complexes,(Ln=La,Eu) have been prepared and characterized.The fluorescent properties of Eu(â…¢) complex in solid state and in different solutions were investigated.DNA-binding study founded that all the compounds,esepecially the complexes,strongly bind with calf-thymus DNA, presumably via an intercalation mechanism.In the fifth chapter,a 6-ethoxy chromone-3-carbaldehyde 2,4-dihydroxy-benzoyl hydrazone ligand(H₃L³) and its Ln(â…¢) complexes,(Ln=La,Sm,Dy and Eu) have been prepared and characterized.The La(â…¢) complex exhibits light green fluorescence under UV light,and the fluorescent properties of and the ligand,La(â…¢), Eu(â…¢) and Sm(â…¢) complexes in solid state and Eu(â…¢) complex in different solutions were investigated.All the experimental evidences indicate that the ligand and the complexes can bind to ct-DNA via an intercalation mechanism.In the sixth chapter,we mainly investigate the interactions of 6-ethoxy chromone-3-carbaldehyde thiosemicarbazone ligand(H₃L⁴) and its two transition metal complexes(Zn and Cu) with calf thymus DNA.