Characterization of oligomeric procyanidins and identification of quercetin glucuronide from lotus ( Nelumbo nucifera Gaertn.) seedpod

J Agric Food Chem. 2012 Mar 21;60(11):2825-9. doi: 10.1021/jf205331e. Epub 2012 Mar 7.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatography, High Pressure Liquid
  • Nelumbo / chemistry*
  • Plant Extracts / chemistry*
  • Polymerization
  • Proanthocyanidins / chemistry*
  • Quercetin / chemistry*
  • Seeds / chemistry*
  • Spectrometry, Mass, Electrospray Ionization

Substances

  • Plant Extracts
  • Proanthocyanidins
  • Quercetin