荧光光谱法测定3种黄酮类化合物与人血清白蛋白相互作用的机制研究

Study on Interaction Mechanism between 3 Kinds of Flavonoids Compounds and Human Serum Albumin by Fluorescence Spectrometry

目的:研究黄酮类化合物与人血清白蛋白(HSA)相互作用的机制,比较化合物B环不同取代基(羟基、甲氧基)对大分子物质结合的影响。方法:采用荧光光谱法对槲皮素、橙皮素、甲基橙皮素3种B环取代基不同的黄酮类化合物与HSA相互作用的规律进行研究,测定并分析3种黄酮类化合物与HSA发生荧光猝灭的类型,计算相应的结合常数、结合位点及热力学参数等。结果:随着温度的升高,猝灭常数(Ksv)均呈规律性下降,结合常数(KA)相应降低,结合位点数(n)近似等于1,热力学参数ΔH<0、ΔS>0,B环的取代基不同对大分子物质结合有影响。结论:3种黄酮类化合物与HSA相互作用发生荧光猝灭的机制属于静态猝灭;结合位点数为1;3种化合物与HSA之间的作用力以静电力为主;羟基可能为黄酮类化合物与大分子物质相互作用的主要活性基团,甲氧基与HSA的结合力小于羟基。

OBJECTIVE：To study the interaction mechanism between flavonoids and human serum albumin（HSA）,and to compare the effects of different B-ring substitutions（hydroxyl,methoxyl group）of flavonoids on macromolecular receptor. METHODS：The interaction regularity between three flavonoids with different B-ring substitutions（quercetin,hesperetin,methyl hesperetin）and HSA was studied with fluorescence spectroscopy,the fluorescence quenching types between 3 flavonoids and HSA were determined and analyzed,and the velated binding constant,binding site and thermodynamic parameters were calculated. RESULTS：The quenching constants（Ksv）and binding constants（KA）were decreased with the increase of temperatures. The number of binding site（n）was approximately equal to one,and the thermodynamic parameters Δ〈H0,ΔS〉0,the binding interaction of these compounds with macromolecules was influenced because of the difference of the B-ring substituents. CONCLUSIONS：The quenching mechanism between three flavonoids and HSA was static quenching;the number of binding site was one;the interaction force of the three compounds with HSA was mainly static electricity,and hydroxyl group in the B-ring was likely the major active group and exerted stronger binding force than methoxyl group to connect with macromolecules.