含硫氨基葡萄糖金属配合物的合成及与DNA和蛋白作用研究

Synthesis of Sulfur-Contained D(+)-Glucosamine Metal Complexes and Interaction with DNA and Serum Albumin

合成了四种含硫氨基葡萄糖金属配合物(M-GLUS,M=Co,Cu,Ni和Zn),利用元素分析,摩尔电导,核磁共振氢谱进行了结构表征。结果表明含硫配体与这四种二价金属离子均形成了2:1型非电解质配合物。在pH7.08Tris缓冲液中,采用紫外吸收光谱和荧光光谱研究了金属配合物与小牛胸腺DNA的作用机制,发现随着金属配合物量的逐渐增加,DNA电子吸收光谱的最大吸收峰呈增色效应,对配合物DNA-EB体系也能产生荧光猝灭作用,说明四种金属配合物均可与DNA发生相互作用,结合方式为部分插入;在近似生理酸度条件下,利用荧光光谱对金属配合物与HSA/BSA的结合特性进行了初步分析,发现配合物均能猝灭HSA/BSA的荧光强度,利用Scatchard方程计算了四种金属配合物与HSA/BSA的结合常数和结合位点数,表明金属配合物与血清白蛋白有较强的结合且只有1类键合位,其中Co-GLUS与蛋白的结合力最强。

Four sulfur-contained D（＋）-glucosamine metal complexes were synthesized （M-GLUS, M = Co, Cu, Ni and Zn）and characterized by elementary analysis, molar conductance, and proton nuclear magnetic resonance. The yield of the complex was about 70%, and it dissolved easily in water. The ligand coordinates with metalions mainly between sulphur and metalions, the coordination molar ratio of the ligand to metalion was 2 ： 1, and the molar conductivity indicated that all the complexes are none- lectrolyte. The mechanism of the interaction between metal complexes and calf thymus （ct） DNA in Tris buffer （pH = 7.08）, was studied by ultraviolet absorption and fluorescence spectroscopy. The results from varied experiments showed that the intensity of the maximal absorption peaks increased with gradual addition of metal complexes, but the metalions can decrease the maximal absorption and the ligand has no effect on it. Meanwhile, metal complexes could remarkably quench the emission intensity of the DNA-EB system, and the metal complexes could be bound to ct DNA. The quenching mechanism was discussed by Stern- Volmer＇s equation, the figure showed that it is influenced by static quenching and dynamic quenching, so the partial interaction of the complexes and ct DNA was the major mode. Under physiological pH condition, this study was designed to examine the effect of complexes on human serum albumin and bovine serum albumin by fluorescence. The binding constants and sites of the interaction with SA were analyzed by the Scatchard＇s equation, the results indicated that there was a strong interaction between the four metal complexes and serum albumin and the binding force was Co-GLUS〉Zn-GLUS〉Cu-GLUS〉Cu-GLUS, and the binding site is only one.