光谱法研究欧前胡素及同分异构体与牛血清白蛋白的相互作用  

Spectroscopic Study on the Interactions of Imperatorin and Isoimperatorin with Bovine Serum Albumin

作　　者：郝娟[1] 张爱平[1] 黄茜[1] 杨锦艳[1] 郑茂东[1] 毛红胜[1] 

机构地区：[1]山西医科大学药学院,山西太原030001

出　　处：《分析测试学报》2010年第11期1173-1179,共7页Journal of Instrumental Analysis

基　　金：山西省自然科学基金资助项目(2010011048-1);山西高校科技研究开发资助项目(2007125);山西医科大学科技创新基金资助项目(01200806)

摘　　要：采用紫外光谱法、荧光光谱法和同步荧光光谱法研究了欧前胡素及其同分异构体异欧前胡素与牛血清白蛋白(BSA)的相互作用。荧光光谱表明,欧前胡素和异欧前胡素对BSA的内源荧光均有显著的猝灭作用,且猝灭机制主要为静态猝灭和非辐射能量转移。308K下欧前胡素和异欧前胡素与BSA的结合常数K分别为1.48×104、1.04×104L·mol-1,结合位点数n分别为0.915、0.742。由热力学数据确定其作用力主要为氢键和范德华力。同步荧光光谱表明,欧前胡素和异欧前胡素与BSA的结合位点更靠近BSA中的色氨酸,引起色氨酸残基附近的疏水性环境减弱,从而使得BSA的构象发生改变。研究表明,香豆素母核上3-甲基-2-丁烯氧基的位置对它们的结合有重要影响,欧前胡素与BSA的作用强于异欧前胡素。The interactions of imperatorin and its isomer isoimperatorin with bovine serum albumin （BSA） were investigated by ultraviolet spectroscopy, fluorescence spectroscopy and synchronous fluorescence spectroscopy under the simulative human physiological conditions. The binding constants, the numbers of binding sites and the thermodynamic parameters were calculated and the effects of imperatorin and isoimperatorin on the conformation of BSA were studied. The results of fluorescence spectroscopy showed that the endogenous fluorescence of BSA was significantly quenched by imperatorin and isoimperatorin, in which the static quenching with non-radiation energy transfer was the main mechanism of fluorescence quenching. The binding parameters of imperatorin and isoimperatorin with BSA were as follows： for imperatorin and isoimperatorin, the binding constants K under 308 K were 1.48 x 10^4 L·mol^-1 and 1.04 × 10^4 L· mol^-1, respectively, and the numbers of binding sites were 0. 915 and 0. 742, respectively. Hydrogen bond and Vander Waals were deduced to be the ma- jor driving forces according to the thermodynamic parameters. The synchronous fluorescence spectra indicated that the binding sites of imperatorin and isoimperatorin with BSA were closer to tryptophan residues. The interaction of imperatorin and isoimperatorin with BSA could result in the decrease of tryptophan residues hydrophobicity and the change of BSA conformation. The results also indicated that the site of 3-methylbut-2-enyloxy in coumarin nucleus played an important role in the interaction of imperatorin and isoimperatorin with BSA, and the interaction force of imperatorin with BSA was stronger than that of isoimperatorin with BSA.

关 键 词：欧前胡素 异欧前胡素 牛血清白蛋白 紫外光谱法 荧光光谱法 同步荧光光谱法 

分 类 号：O561.3[理学—原子与分子物理] O629.73[理学—物理]