系列黄酮化合物与血清白蛋白结合及其结构相关性

目的比较具有不同取代基基团的八种黄酮类化合物与牛血清白蛋白(BSA)的相互作用及与其结构的相关性。方法基于黄酮化合物能够猝灭色氨酸残基的内源性荧光,采用荧光光谱法研究黄酮类化合物与BSA结合作用,根据荧光猝灭方程计算黄酮类化合物与BSA的表观结合常数(KA)和结合位点数。结果八种黄酮类植物化学物与BSA的结合强弱依次为:橙皮素(5.59×105)>槲皮素(4.94×105)>柚皮素(3.04×105)>异槲皮素(4.66×104)>淫羊藿苷(3.60×104)>芦丁(1.65×104)>橙皮苷(2.50×103)>柚皮苷(8.70×102)。结论糖苷基取代对黄酮类化合物与BSA的结合作用有很大影响,A环可能是黄酮类化合物插入BSA疏水区的关键部位,其C7位上的糖苷基取代是影响其与BSA结合的关键基团。此研究探讨了黄酮类化合物与BSA的作用及其与结构相关性规律,对了解黄酮类化合物在体内的运输、代谢和分布提供了一定实验依据。

The binding and structural association of flavonoids with bovine serum albumin

Purpose To investigate the binding capacities and structural association of eight flavonoids with similar core structure with bovine serum albumin(BSA).Methods As the flavonoids can quench the intrinsic fluorescence of tryptophan residues,the apparent association constant(KA) and the number of flavonoids binding to BSA were determined by fluorescence spectroscopy following the derived fluorescence quenching equation.Results The binding capacities of eight flavonoid phytochemicals were ordered as hesperetin(5.59×105)>quercetin(4.94×105)>naringenin(3.04×105)>isoquercitrin(4.66×104)>icariin(3.60×104)>rutin(1.65×104) > hesperidin(2.50×103)>naringin(8.70×102).Conclusion Glycoside substituent plays an important role in the interaction of flavonoids with BSA.The A ring of flavonoids should be the critical structural component merging into the hydrophobic region of BSA.The group at the site of C7 was the key group interrupting the binding of flavonoid to BSA.The current work investigated the interaction and structural basis of flavonoids binding to BSA.The results provided certain experimental data for revealing the transport,metabolism and distribution of flavonoids in vivo.