Targeted acylation for all the hydroxyls of (+)-catechin and evaluation of their individual contribution to radical scavenging activity

卷:197

Hong, Shan ; Liu, Songbai

Zhejiang Univ

关键词: Catechin;    Acylation;    Hydroxyl;    Antioxidant activity;    Radical scavenging activity;   

DOI  :  10.1016/j.foodchem.2015.10.134

学科分类：食品科学和技术

【 摘 要 】

The reactivity profile of all the hydroxyl groups in (+)-catechin towards acylation and their respective contribution to radical scavenging activity were systematically explored in this work. Selective acylation of the hydroxyls on different rings was carried out employing either a basic or acidic activation strategy. Monoacylation of B ring was achieved effectively with the aid of dimethyltin dichloride. Monoacylation of A ring was accomplished by sequential protection and deprotection of B and C rings. Based on specific acylation of all the individual hydroxyls of (+)-catechins, the structure radical scavenging activity relationship of each hydroxyl of (+)-catechin was established. It was demonstrated that the vicinal phenolic hydroxyls on B ring played the most important role in the ABTS radical scavenging activity and those on A and C rings made a much smaller contribution. This study has laid solid groundwork for further modification of the catechins and improvement of their properties. (C) 2015 Elsevier Ltd. All rights reserved.