Isolation and Structural Elucidation of Some Procyanidins from Apple by Low-Temperature Nuclear Magnetic Resonance

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• 作者：Toshihiko Shoji ; Motoh Mutsuga ; Takatoshi Nakamura ; Tomomasa Kanda ; Hiroshi Akiyama ; and Yukihiro Goda
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2003
• 出版时间：June 18, 2003
• 年：2003
• 卷：51
• 期：13
• 页码：3806 - 3813
• 全文大小：144K
• 年卷期：v.51,no.13(June 18, 2003)
• ISSN：1520-5118

文摘

Procyanidin fractions from apple were separated according to the degree of polymerization usingnormal phase chromatography. Evaluation of physiological functionalities of procyanidins requiresindividual structural determination. However, it is difficult to elucidate the structure of procyanidins,in particular those with (+)-epicatechin (1) or (-)-catechin (2) units, and determine whether theinterflavanoid bonds are 48 or 46 without cleavage and acetylation. Structural determinationused LC-MS and low-temperature NMR. Nine procyanidins were separated by preparative HPLCconsisting of three well-known procyanidins [procyanidin B1 (3), procyanidin B2 (4), and procyanidinC1 (5)] and six new procyanidins [epicatechin-(48)-epicatechin-(48)-catechin (6); epicatechin-(46)-epicatechin-(48)-catechin (7); epicatechin-(46)-epicatechin-(48)-epicatechin (8);epicatechin-(48)-epicatechin-(46)-catechin (9); epicatechin-(48)-epicatechin-(46)-epicatechin (10); and epicatechin-(48)-epicatechin-(48)-epicatechin-(48)-epicatechin (11)].Compounds 6-11 were detected for the first time as apple constituents.Keywords: NMR; apple; procyanidins; tetramer; trimer