光谱法比较木犀草素及槲皮素与牛血清白蛋白相互作用

在模拟生理pH条件下,采用荧光光谱、紫外-可见吸收光谱、同步荧光光谱和圆二色谱法研究木犀草素及槲皮素与牛血清白蛋白（BSA）的相互作用的异同.结果确定木犀草素及槲皮素对BSA的荧光猝灭是以静态猝灭为主,同时伴随非辐射能量转移猝灭.木犀草素结合BSA的位点与荧光发射基团的距离比槲皮素的小.结合常数Ka表明二者与BSA的结合都属于强的非共价键结合,且结合位点数都约为1.二者均主要通过氢键和范德华力与BSA作用.二者都能影响BSA的酪氨酸残基附近环境的极性,且高浓度下能够引起BSA构象轻微地改变.结果表明黄酮C环上3位羟基的引入会降低其对BSA的亲和力.

Comparison of the Interaction of Luteolin and Quercetin with Bovine Serum Albumin by Spectroscopic Methods

The interaction of luteolin and quercetin with bovine serum albumin （BSA） was investigated under simulated synchronous fluorescence and physiological conditions by circular diehroism （CD）. They fluorescence, UV-Vis spectroscopy, quenched the intrinsic fluorescence of BSA through static quenching mechanism, along with non-radiation energy transfer. Binding distance （r） between emitting fluorescence groups of BSA and luteolin is shorter than that of BSA and quercetin. The binding constants K, with BSA showed that the combination of the two and BSA are strong . And binding sites （n） are about one at different temperatures. The binding force of luteolin or quercetin to BSA involved hydrogen bonding and van der Waals forces . Both luteolin and quercetin can affect the polar near the tyrosine residues environment of BSA. They can cause slight changes in the conformation of BSA at high concentration. The result also showed that hydroxyl group on ring C could decrease the affinities for BSA.