Identification of two novel proanthocyanidins in green tea
Identification of two novel proanthocyanidins in green tea
复制标题
DOI：
10.1021/jf9813081
复制
发表时间：
1999-11-01
影响因子：
6.1
通讯作者：
Wray, V
中科院分区：
文献类型：
--
作者：
Lakenbrink, C;Engelhardt, UH;Wray, V
描述了绿茶样品中表儿茶素没食子酸酯-(4β-->8)-表儿茶素没食子酸酯 (EAG-4β-->8-ECG) 和表儿茶素没食子酸酯-(4β-->6)-表儿茶素没食子酸酯 (EAG-4β-->6-ECG) 的分离和结构解析。各种 2D NMR 技术的结合可以对未衍生化的原花青素进行完整的结构测定，尽管信号的展宽不允许观察到表征类黄酮间键合位置的一些关键相关性。新化合物的 NMR 谱的差异允许制定区分此类化合物中 4→6 和 4→8 异构体的标准。
The isolation and structural elucidation of epiafzelechingallate-(4 beta-->8)-epicatechingallate (EAG-4 beta-->8-ECG) and epiafzelechingallate-(4 beta-->6)-epicatechingallate (EAG-4 beta-->6-ECG) in green tea samples are described. The combination of various 2D NMR techniques allowed a full structural determination of the underivatized proanthocyanidins even though broadening of the signals did not allow observation of some key correlations that characterize the location of the interflavonoid linkage. The differences in the NMR spectra of the new compounds allowed formulation of criteria for the discrimination between the 4-->6 and 4-->8 isomers in this type of compound.