Identification of Two Novel Proanthocyanidins in Green Tea
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- 作者：Christiane Lakenbrink ; Ulrich H. Engelhardt ; and Victor Wray
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：1999
- 出版时间：November 1999
- 年：1999
- 卷：47
- 期：11
- 页码：4621 - 4624
- 全文大小：51K
- 年卷期：v.47,no.11(November 1999)
- ISSN：1520-5118
文摘
The isolation and structural elucidation of epiafzelechingallate-(4
8)-epicatechingallate (EAG-48-ECG) and epiafzelechingallate-(46)-epicatechingallate (EAG-46-ECG) in green teasamples are described. The combination of various 2D NMR techniques allowed a full structuraldetermination of the underivatized proanthocyanidins even though broadening of the signals didnot allow observation of some key correlations that characterize the location of the interflavonoidlinkage. The differences in the NMR spectra of the new compounds allowed formulation of criteriafor the discrimination between the 46 and 48 isomers in this type of compound.Keywords: Camellia sinensis; tea; proanthocyanidins; HPLC/MS; NMR; epiafzelechingallate-(48)-epicatechingallate; epiafzelechingallate-(46)-epicatechingallate
8)-epicatechingallate (EAG-48-ECG) and epiafzelechingallate-(46)-epicatechingallate (EAG-46-ECG) in green teasamples are described. The combination of various 2D NMR techniques allowed a full structuraldetermination of the underivatized proanthocyanidins even though broadening of the signals didnot allow observation of some key correlations that characterize the location of the interflavonoidlinkage. The differences in the NMR spectra of the new compounds allowed formulation of criteriafor the discrimination between the 46 and 48 isomers in this type of compound.Keywords: Camellia sinensis; tea; proanthocyanidins; HPLC/MS; NMR; epiafzelechingallate-(48)-epicatechingallate; epiafzelechingallate-(46)-epicatechingallate