Acid Mediated Hydrolysis of Blueberry Anthocyanins.
作者:Takashi ICHIYANAGI、Kikuo OIKAWA、Chigusa TATEYAMA、Tetsuya KONISHI
DOI:10.1248/cpb.49.114
日期:——
Acid mediated hydrolysis of anthocyanins was studied using capillary zone electrophoresis (CZE). A commercially available wild blueberry (Bilberry) extract was dissolved in different concentrations of TFA (0.1, 1, 3, 9%), then was subjected to thermodecomposition reaction at 95 °C. After the reaction, the samples were analyzed by CZE. The hydrolysis rate of each anthocyanin and the formation of the aglycon were determined by the change in the peak pattern of the anthocyanins in the electropherogram. Each anthocyanin peak decreased time dependently in a first order kinetic fashion. It was revealed that the hydrolysis rate of each anthocyanin was determined primarily by the type of conjugated sugar and not by the aglycon structure. The rate constant of anthocyanin hydrolysis was in the following order, arabinoside>galactoside>glucoside without regard to the aglycon structure. The kinetic behavior of this anthocyanin hydrolysis together with the CZE mobility allowed us to identify an unknown CZE peak as delphinidin 3-O-β-arabinoside. At low TFA concentration, significant decomposition of the anthocyanidin nucleus occurred, but the glycoside hydrolysis predominated at high TFA concentration. It was further revealed that the aglycon released reacted successively to form polymeric products at higher TFA conditions.
使用毛细管区带电泳 (CZE) 研究了酸介导的花青素水解。将市售的野生蓝莓(Bilberry)提取物溶解在不同浓度的TFA(0.1、1、3、9%)中,然后在95℃下进行热分解反应。反应后,通过 CZE 分析样品。通过电泳图中花青素峰模式的变化来确定每种花青素的水解速率和苷元的形成。每个花青素峰以一级动力学方式随时间下降。结果表明,每种花青素的水解率主要由共轭糖的类型决定,而不是由苷元结构决定。花青素水解速率常数的顺序为:阿拉伯糖苷>半乳糖苷>葡萄糖苷,与苷元结构无关。这种花青素水解的动力学行为以及 CZE 迁移率使我们能够将未知的 CZE 峰识别为花翠素 3-O-β-阿拉伯糖苷。在低TFA浓度下,花青素核发生显着分解,但在高TFA浓度下糖苷水解占主导地位。进一步揭示,释放的苷元在较高的TFA条件下连续反应形成聚合产物。