title: 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.
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.
authors.affiliation: Laboratory of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, University of Athens, Panepistimioupolis-Zografou, Athens, 15771, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Halabalaki
authors.forename: Aurélie
authors.initials: A
authors.lastname: Urbain
authors.forename: Aristea
authors.initials: A
authors.lastname: Paschali
authors.forename: Sofia
authors.initials: S
authors.lastname: Mitakou
authors.forename: François
authors.initials: F
authors.lastname: Tillequin
authors.forename: Alexios-Leandros
authors.initials: AL
authors.lastname: Skaltsounis
mesh_terms: D007887:Fabaceae / Q000737:chemistry*; D006027:Glycosides / Q000737:chemistry* / Q000302:isolation & purification*; D006031:Glycosylation; D006115:Greece; D044949:Kaempferols / Q000737:chemistry* / Q000302:isolation & purification*; D015394:Molecular Structure; D011794:Quercetin / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification; D013237:Stereoisomerism
chemical_list: D006027:Glycosides; D044949:Kaempferols; C567948:kaempferol 3-O-(alpha-rhamnopyranosyl-(1-2)-alpha-L-arabinopyranoside)-7-O-alpha-L-rhamnopyranoside; C567949:quercetin 3-O-(alpha-L-rhamnopyranosyl-(1-2)-alpha-L-arabinopyranoside)-7-O-alpha-L-rhamnopyranoside; D011794:Quercetin