Quercetin and kaempferol 3-O-[α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside]-7-O-α-L-rhamnopyranosides from Anthyllis hermanniae: structure determination and conformational studies

J Nat Prod. 2011 Sep 23;74(9):1939-45. doi: 10.1021/np200444n. Epub 2011 Aug 23.

Abstract

The study reports the isolation and structural identification of two new flavonol triglycosides from the methanolic extract of Anthyllis hermanniae, exhibiting the same glycosylation pattern: quercetin 3-O-[α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside]-7-O-α-L-rhamnopyranoside (1) and kaempferol 3-O-[α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside]-7-O-α-L-rhamnopyranoside (2). A conformational study related to the central arabinoside moiety was carried out including the analysis of the contribution of NOE effects and acetylation to the elucidation of the 2-O-linked arabinoside configuration of the anomeric carbon. We also report the total synthesis of a model compound, quercetin 3-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside (3), which verifies the structures of the isolated compounds.

MeSH terms

  • Fabaceae / chemistry*
  • Glycosides / chemistry*
  • Glycosides / isolation & purification*
  • Glycosylation
  • Greece
  • Kaempferols / chemistry*
  • Kaempferols / isolation & purification*
  • Molecular Structure
  • Quercetin* / analogs & derivatives
  • Quercetin* / chemistry
  • Quercetin* / isolation & purification
  • Stereoisomerism

Substances

  • Glycosides
  • Kaempferols
  • kaempferol 3-O-(alpha-rhamnopyranosyl-(1-2)-alpha-L-arabinopyranoside)-7-O-alpha-L-rhamnopyranoside
  • quercetin 3-O-(alpha-L-rhamnopyranosyl-(1-2)-alpha-L-arabinopyranoside)-7-O-alpha-L-rhamnopyranoside
  • Quercetin