Interactions between polyphenols in thinned young apples and porcine pancreatic α-amylase: Inhibition, detailed kinetics and fluorescence quenching
Interactions between polyphenols in thinned young apples and porcine pancreatic α-amylase: Inhibition, detailed kinetics and fluorescence quenching
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DOI：
10.1016/j.foodchem.2016.03.093
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发表时间：
2016-10-01
期刊：
影响因子：
8.8
通讯作者：
Guo, Yurong
中科院分区：
文献类型：
--
作者：
Sun, Lijun;Chen, Weiqi;Guo, Yurong
研究了青苹果多酚（雅普）和9种酚类化合物对猪胰α-淀粉酶（PPA）的体外抑制活性。雅普中的单宁酸、绿原酸和咖啡酸具有较强的抑制作用，IC 50值分别为0.30、1.96和3.69 mg/mL。详细的抑制动力学研究表明，雅普和单宁酸是PPA的竞争性抑制剂，而绿原酸和咖啡酸是混合抑制剂，表现出竞争性和非竞争性的特点。雅普和3种多酚对PPA的荧光均有显著的猝灭作用，并测定了它们的猝灭常数。结果表明，多酚类化合物的表观静态猝灭常数（K-FQ）和竞争抑制常数倒数（1/K-ic）的大小顺序一致（单宁酸>绿原酸>咖啡酸>表儿茶素），但与IC_（50）大小顺序相反。因此，结合详细的动力学和荧光猝灭的研究，可以适用于年轻的苹果多酚和α-淀粉酶之间的相互作用。(C)2016爱思唯尔有限公司版权所有。
Young apple polyphenols (YAP) and nine types of phenolic compounds were investigated regarding the inhibitory activity against porcine pancreatic alpha-amylase (PPA) in vitro. Tannic acid, chlorogenic acid and caffeic acid in YAP showed relatively high inhibition with the IC50 values of 0.30, 1.96 and 3.69 mg/mL, respectively. A detailed kinetics of inhibition study revealed that YAP and tannic acid were competitive inhibitors of PPA, whereas chlorogenic acid and caffeic acid were mixed inhibitors, exhibiting both competitive and uncompetitive characteristics. The fluorescence of PPA could be significantly quenched by YAP and the three polyphenols, and their quenching constants were determined. The results showed that for the polyphenols investigated, the order of the apparent static quenching constants (K-FQ) was in agreement with that of the reciprocal competitive inhibition constants (1/K-ic) (tannic acid > chlorogenic acid > caffeic acid > epicatechin); both of the parameters were contrary to the order of the IC50 values. Thus, combining detailed kinetics and fluorescence quenching studies can be applied to characterise the interactions between polyphenols in young apples and alpha-amylase. (C) 2016 Elsevier Ltd. All rights reserved.