Es-Safi N E, Fulcrand H, Cheynier V, Moutounet M
ISVV-INRA Institut des Produits de la Vigne, Unité de Recherche Biopolymères et Arômes, Montpellier, France.
J Agric Food Chem. 1999 May;47(5):2096-102. doi: 10.1021/jf9806309.
The reaction between (-)-epicatechin, malvidin 3-O-glucoside, and acetaldehyde was studied in a model solution system. Ethyl-linked flavanol oligomers and anthocyanin-flavanol derivatives were observed, showing that the two polyphenols competed in the condensation process. Among the anthocyanin-ethyl-flavanol adducts, dimeric compounds in which the flavanol was linked to the anthocyanin with CH(3)-CH bridges were observed. In addition, trimeric and tetrameric products containing one anthocyanin and one, two, or three flavanols units were detected. A tetrameric product containing two anthocyanin and two flavanol units was also found as a doubly charged ion. No compound containing more than two malvidin 3-O-glucosides was detected, suggesting that only one anthocyanin A ring summit can be included in the polymerization process, which thus stops when both ends are occupied by an anthocyanin moiety. Thioacidolysis of the two isolated anthocyanin-ethyl-flavanol dimeric derivatives showed that anthocyanin-ethyl linkage was not sensitive to such reactants, whereas the flavanol-ethyl one was. In addition, flavanol-ethyl linkages involved in anthocyanin-ethyl-flavanol adducts were found to be less sensitive to those involved in flavan-ethyl dimers.
在模型溶液体系中研究了（-）-表儿茶素、锦葵色素3-O-葡萄糖苷和乙醛之间的反应。观察到了乙基连接的黄烷醇低聚物和花青素-黄烷醇衍生物，表明这两种多酚在缩合过程中相互竞争。在花青素-乙基-黄烷醇加合物中，观察到了黄烷醇通过CH(3)-CH桥与花青素相连的二聚体化合物。此外，还检测到了含有一个花青素和一个、两个或三个黄烷醇单元的三聚体和四聚体产物。还发现了一种含有两个花青素和两个黄烷醇单元的四聚体产物作为双电荷离子。未检测到含有两个以上锦葵色素3-O-葡萄糖苷的化合物，这表明在聚合过程中只能包含一个花青素A环顶端，因此当两端都被花青素部分占据时聚合反应就会停止。对两种分离出的花青素-乙基-黄烷醇二聚体衍生物进行硫代酸解表明，花青素-乙基键对这类反应物不敏感，而黄烷醇-乙基键则敏感。此外，发现花青素-乙基-黄烷醇加合物中涉及的黄烷醇-乙基键对黄烷-乙基二聚体中涉及的黄烷醇-乙基键不太敏感。
