Abstract：
Polyphenol has the considerable effects for inhibition of digestive enzymes, however, inhibition mechanism of molecular size-dependent polyphenols on enzyme activity is still lacking. Herein, inhibition effect and binding interactions of three different structural polyphenols (catechol, quercetin and hesperidin) on α-amylase were studied. Inhibition assays proved that polyphenols significantly inhibited α-amylase and their effects were increased with their molecular sizes. Hesperidin showed the highest inhibition ability of α-amylase, which was determined as IC50 = 0.43 mg/mL. Fluorescence and FT-IR spectroscopy proved that inter-molecular interactions between polyphenols and α-amylase occurred through non-covalent bonds. Besides, the secondary structure of α-amylase was obviously changed after binding with polyphenols. Inter-molecular interactions were investigated using solid-state NMR and molecular docking. Findings proved that hydrogen bonds and π-π stacking interactions were the mainly inter-molecular interactions. We hope this contribution could provide a theoretical basis for developing some digestive enzyme inhibitors from natural polyphenols.
摘要：
多酚对消化酶有相当大的抑制作用，然而,分子大小依赖性多酚对酶活性的抑制机制尚缺乏。在这里，三种不同结构多酚(儿茶酚，研究了槲皮素和橙皮苷）对α-淀粉酶的影响。抑制实验证明，多酚显着抑制α-淀粉酶，其作用随分子大小而增加。橙皮苷对α-淀粉酶的抑制能力最高,其测定为IC50=0.43mg/mL。荧光和红外光谱证明，多酚和α-淀粉酶之间的分子间相互作用是通过非共价键发生的。此外,α-淀粉酶与多酚结合后二级结构发生明显变化。使用固态NMR和分子对接研究了分子间相互作用。研究结果表明，氢键和π-π堆积相互作用是主要的分子间相互作用。我们希望这一贡献可以为从天然多酚中开发一些消化酶抑制剂提供理论依据。
