title: Characterization of oligomeric procyanidins and identification of quercetin glucuronide from lotus ( Nelumbo nucifera Gaertn.) seedpod.
abstract: 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-β-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.
authors.affiliation: Beijing Higher Institution Engineering Research Center of Food Additives and Ingredients, Beijing Technology and Business University-BTBU, Beijing 100048, People's Republic of China.
authors.forename: Jun-Song
authors.initials: JS
authors.lastname: Xiao
authors.forename: Bi-Jun
authors.initials: BJ
authors.lastname: Xie
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Cao
authors.forename: Hua
authors.initials: H
authors.lastname: Wu
authors.forename: Zhi-Da
authors.initials: ZD
authors.lastname: Sun
authors.forename: Di
authors.initials: D
authors.lastname: Xiao
mesh_terms: D002851:Chromatography, High Pressure Liquid; D031653:Nelumbo / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D058105:Polymerization; D044945:Proanthocyanidins / Q000737:chemistry*; D011794:Quercetin / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D010936:Plant Extracts; D044945:Proanthocyanidins; D011794:Quercetin