白皮杉醇和白藜芦醇与BSA相互作用的荧光光谱法研究

摘要

目的：研究白皮杉醇(piceatannol)和白藜芦醇(resveratrol)与牛血清白蛋白(BSA)相互作用之区别,探索苯环羟基取代对二苯乙烯与BSA相互作用的影响。方法应用荧光光谱法和紫外光谱技术对二苯乙烯类化合物白皮杉醇和白藜芦醇与BSA之间的相互作用进行研究,计算这2种化合物与BSA的结合常数和结合位点数及热力学函数ΔG、ΔS、ΔH,并分析了它们对 BSA的荧光淬灭过程及其之间的相互作用类型,运用了 Foerster′s偶极-偶极非辐射能量转移原理测定与牛血清白蛋白的结合距离。结果随着白皮杉醇和白藜芦醇浓度升高,BSA内源荧光强度有规律地下降；随温度的升高,静态淬灭常数和结合常数均下降；热力学函数ΔG0,ΔH<0。结论白皮杉醇和白藜芦醇对BSA的荧光淬灭属于自发的以疏水作用力为主导的非辐射能量转移的静态淬灭过程,且通过比较发现,白皮杉醇与BSA的结合力比白藜芦醇强。%Obj ective In order to explore the interactions between piceatannol or resveratrol and BSA.Methods The interactions between BSA and the two stilbene compounds,piceatannol and resveratrol,were studied by fluorescence spectroscopy.The respec-tive binding constant Ka ,the number of binding sites of each compound as well as thermodynamic parametersΔG,ΔS andΔH were calculated.The binding distance between each compound and BSA was obtained by Foerster′s dipile-dipile non-radiation energy transfer mechanism.Results The fluorescence intensity of BSA decreased regularly with the addition of the two compounds,re-spectively.The static quenching constants and binding sites were all decreased with an increase of temperature.Thermodynamic pa-rametersΔS was higher than 0 while both ofΔG andΔH were lower than 0.Conclusion The thermodynamic parameters suggested the binding of each compound with BSA proceed spontaneously,and was mainly dominated by hydrophobic forces.Non-radiation energy transfer occurred,and the interaction between piceatannol and BSA was more active than that of resveratrol.