Whistler Center for Carbohydrate Research and Department of Food Science, Purdue University, West Lafayette, IN 47907, USA.
Plants for Human Health Institute, North Carolina State University, Kannapolis, NC 28081, USA; Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27606, USA.
Food Chem. 2022 Feb 15;370:130981. doi: 10.1016/j.foodchem.2021.130981. Epub 2021 Aug 30.
In the present study, 14 structurally unique flavonoids were screened to systematically investigate structural requirements for selectively inhibiting human α-amylase versus α-glucosidase to obtain a slow but complete starch digestion for health benefit. The selective inhibition property of three flavonoids chosen against the two classes of starch digestive enzymes was confirmed through various analytical techniques - in vitro inhibition assay, fluorescence quenching, kinetic study, and molecular modeling. Considering the chemical structure of flavonoids, the double bond between C2 and C3 and OH groups at A5 and B3 are critical for the inhibition of α-amylase allowing flavonoids to lie parallel on the α-amylase catalytic active site, whereas the OH groups at B3 and C3 are important for α-glucosidase inhibition causing B-ring specific entry into the catalytic active site of α-glucosidase. Our findings provide insights into how to apply flavonoids to effectively control digestion rate for improving physiological responses.
在本研究中，筛选了 14 种结构独特的类黄酮，以系统研究选择性抑制人α-淀粉酶与α-葡萄糖苷酶的结构要求，从而获得缓慢但完全的淀粉消化，有益于健康。通过各种分析技术——体外抑制试验、荧光猝灭、动力学研究和分子建模，证实了选择的三种类黄酮对两类淀粉消化酶的选择性抑制特性。考虑到类黄酮的化学结构，C2 和 C3 之间的双键以及 A5 和 B3 上的 OH 基团对于抑制α-淀粉酶至关重要，使类黄酮能够平行于α-淀粉酶的催化活性部位，而 B3 和 C3 上的 OH 基团对于α-葡萄糖苷酶的抑制很重要，导致 B 环特异性进入α-葡萄糖苷酶的催化活性部位。我们的研究结果为如何应用类黄酮来有效控制消化率以改善生理反应提供了思路。
