Characterization of Oligomeric Procyanidins and Identification of Quercetin Glucuronide from Lotus (Nelumbo nucifera Gaertn.) Seedpod

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• 作者：Jun-Song Xiao ; Bi-Jun Xie ; Yan-Ping Cao ; Hua Wu ; Zhi-Da Sun ; Di Xiao
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2012
• 出版时间：March 21, 2012
• 年：2012
• 卷：60
• 期：11
• 页码：2825-2829
• 全文大小：257K
• 年卷期：v.60,no.11(March 21, 2012)
• ISSN：1520-5118

文摘

Procyanidins are a class of polyphenols in the plant kingdom. Lotus (Nelumbo nucifera Gaertn.) seedpods, the inedible part of lotus and a byproduct during the production of lotus seeds, were found to be a new source rich in procyanidins. Detailed information about oligomeric procyanidins in lotus seedpods remains unknown. In this study, lotus seedpods were extracted using 60% aqueous methanol and characterized with phloroglucinolysis and liquid chromatography (mass spectrometry with an electrospray ionization source). The results indicate that the oligomeric and polymeric fraction had a mean degree of polymerization of 3.2 and 15.4, respectively, and consisted of (+)-catechin (m/z 289), gallocatechin or epigallocatechin (m/z 305), quercetin glycoside (m/z 463), quercetin glucuronide (m/z 477), procyanidin dimers (m/z 577.1), proanthocyanidin dimer gallate (m/z 593.3), prodelphinidin dimers (m/z 609.1), procyanidin trimers (m/z 865.1), etc. Quercetin glucuronide was further purified using flash chromatography and identified as quercetin-3-O-尾-glucuronide by determining its exact mass using ion-trap time-of-flight mass spectrometry and ¹H and ¹³C nuclear magnetic resonance, ¹H-detected heteronuclear single-quantum coherence, and ¹H-detected heteronuclear multiple-bond correlation analyses.

Keywords:

lotus seedpod; procyanidins; gallocatechin; quercetin-3-O-尾-glucuronide; exact mass; HSQC; HMBC