Synthesis And Characterization Of Cu(Ⅱ) Complexes And Their Interactions With Human Serum Albumin And Antitumor Mechanisms

In this paper,the reaction product of 2-dipyridyl ketone with four kinds of thiosemicarbazide derivatives and isopropyl-2-pyridone or 2-benzoylpyridine with thiocarbazide are prepared for the ligand,Cu as the central atom,four binuclear copper complexes and two tetranuclear copper complexes were synthesized by solution method.These complexes were characterized by IR,ESI-MS,element analysis and X-single crystal diffraction method.At the molecular level,we used UV-Vis absorption,fluorescence spectroscopy and X-ray analysis to explore the interactions of these copper complexes with human serum albumin(HSA)and DNA,also the Western Blot analysis method were used for the detection of the expression of some related proteins after the complex acts on tumor cells.From the cellular level,antitumor activity of these copper complexes and the mechanism of tumor cells apoptosis induced were studied by cell experiments.The specific research contents are as follows:2-dipyridyl ketone was reacted with four kinds of thiosemicarbazone derivatives(4,4-dimethyl-thiosemicarbazide,4,4-diethyl-thiosemicarbazide,3-pyrrolidine-3-thiosemicarbazid e,3-piperidine-3-thiosemicarbazide)as the ligand(L1-L4),and then the four kinds of copper complexes were synthesized by solution method,characterized by IR,ESI-MS,elemental analysis,and single crystal analysis.Respectively as Cl:[CuCl(L1)]2,C2:[CuBr(L2)]2,C3:[CuCl(L3)]2,C4:[CuCl(L4)]2.These complexes are all binuclear,and all conclude two thiosemicarbazone ligands,two copper metal atoms,two halogen atoms.The Nl-Culi,Nli-Cul of these complexes can be broken down in aqueous solutions by ESI-MS,so that these complexes are present in mononuclear form in aqueous solution.Human serum albumin(HSA)is considered to be an excellent drug carrier with non-toxic,non-antigenic,good biocompatibility and biodegradable properties and the IIA subdomain HSA a larger hydrophobic cavity.The amino acid residues in the cavity can provide N atoms coordinated to Cu,so we can bind the four copper complexes to HSA.We also obtain the HSA complex crystal structure by synchrotron radiation X-ray analysis;the results were further confirmed by fluorescence spectroscopy and ESI-TOF-MS.In vitro cell experiments showed that the four complexes had good antitumor activity against the four tumor cells of MGC-803,HePG-2,Bel-7402 and SKOV-3.Compared with the naked medicine,anti-tumor activity of these complexes binding with human serum albumin was increased.In this study,we selected complex C1 and its albumin complex to act on liver cancer cell Bel-7402 as the study object to find that the inhibition of cell cycle in S pHSAe,through endogenous mitochondria mediated pathway induced tumor cell apoptosis,and with anti-apoptotic Protein Bcl-2 family regulation.Isopropyl-2-pyridone or 2-benzoylpyridine was reacted with thiocarbazide as the ligand(L1-L2),and then the two kinds of copper complexes were synthesized by solution method,characterized by IR,ES1-MS,element analysis,and single crystal analysis.Respectively as C1:[Cu2Cl2(L1)]2,C2:[Cu2Cl2Ll)]2.The two copper complexes are all tetranuclear structure,all complexes are belonging to the monoclinic space group,and all conclude two thiosemicarbazone ligands,four copper metal atoms,four chlorine atoms.MTT activity screening experiments show that they have a strong anti-tumor activity,and then its anti-tumor function in vitro studies have found that can induce apoptosis,resulting in increased reactive oxygen species,mitochondrial membrane potential decreased,resulting in cell cycle disorders,thereby promoting apoptosis,can interact with DNA,topoisomerase I to inhibit cell proliferation,also inhibit the migration of cells in a certain way.Therefore,these two complexes can achieve the anti-tumor function by the synergistic effect of these methods,and in this process is accompanied by the regulation of Bcl family protein and migration-related protein MACC-1 protein.