人唾液α-淀粉酶与红/绿茶多酚相互作用的吸附动力学研究

Adsorption kinetic study of the interaction between human salivary α-amylase and the polyphenoles from the black/green tea

目的探索茶黄素(TF)和表没食子儿茶素没食子酸酯(EGCG)与人唾液α-淀粉酶(HSA)反应所引起的口腔收敛性感觉的驱动力。方法利用表面等离子共振仪(SPR)和吸附动力学原理,测量Langmuir、Freundlich吸附等温线常数(KL、Kf和Mm)和吸附反应速率及平衡常数(ka、kd、KA和KD)。结果 TF和EGCG在2种模型下的相关决定系数之间的差异无统计学意义(P>0.05),均适用于描述TF和EGCG的吸附现象。TF的吸附等温线常数、结合速率和结合平衡常数均大于EGCG(P<0.05),解离速率和解离平衡常数均小于EGCG(P<0.05)。结论红茶中的TF比绿茶中的EGCG更易造成口腔黏膜强烈的收敛性感觉,其驱动力来源于多酚结构中的羟基的氢键结合和酰基的疏水性反应。

Objective To explore the driving force of the oral astringency produced by the interaction of theaflavin（TF） and epigallocatechin-3-gallate（EGCG） to human salivary α-amylase（HSA）.Methods The constants of the rate,equilibrium of reaction（ka,kd,KA,and KD） and Langmuir,Freundlich adsorption isotherm（KL,Kf,and Mm） were determined by surface plasmon resonance（SPR） technique and adsorption kinetics.Results Both of Langmuir and Freundlich models could be used for describing the binding processes of TF and EGCG onto HSA surfaces,and there were no significant differences of the correlation coefficient of determination between these two models（P0.05）.The constants of adsorption isotherm,the rate and equilibrium constants of the association for TF were higher than those of EGCG（P0.05）.The rate and equilibrium constants of the dissociation for TF were lower than those of EGCG（P0.05）.The affinity of TF to HSA was higher than that of EGCG.Conclusion The sorely oral astringency is much easily produced by TF from the black tea rather than EGCG from the green tea.The driving force of the oral astringency is attributed to the hydrogen bonds of hydroxyl groups and hydrophobic interaction of galloyl groups in polyphenolic structures.