Untitled Document

Records of Natural Products

Year: 2014 Volume: 8 Issue: 1

ORIGINAL ARTICLE

A New Flavonol Triglycoside and Other Flavonol Glycosides from Astragalus armatus Willd. (Fabaceae)

Assia Khalfallah, Anastasia Karioti, Djemaa Berrehal, Ahmed Kabouche, Massimo Lucci, Anna Rita Bilia and Zahia Kabouche

University of Constantine 1 , Department of Chemistry, Laboratory of Therapeutic Substances (LOST), Campus Chaabet Ersas, 25000 Constantine, Algeria,

Department of Pharmaceutical Sciences, University of Florence, Ugo Schiff 6, 50019, Sesto Fiorentino (FI), Italy,

Magnetic Resonance Center, Via Luigi Sacconi 6, 50019 Sesto Fiorentino (FI), Italy

Abstract: From the aerial parts of Astragalus armatus, a new acylated flavonol triglycoside, isorhamnetin-3-O-(5'''-p-hydroxybenzoyl)-β-apiofuranosyl-(1→2)[ α -rhamnopyranosyl-(1→6)]- β -galactopyranoside (1) which we named astrarmatuside, has been isolated and structurally elucidated together with seven known flavonol glycosides: tamarixetin-3-O- α -apiofuranosyl-(1→2)[ α -rhamnopyranosyl-(1→6)]- β -galactopyranoside (2) (m illettias p ec oside D) , isorhamnetin-3-O-β-apiofuranosyl-(1→2)[α-rhamnopyranosyl-(1→6)]-β-galacto-pyranoside (3), kaempferol-3-O-α-rhamnopyranosyl-(1→2)[α-rhamnopyranosyl-(1→6)]-β-glucopyranoside (4), kaempferol-3-O-α-rhamnopyranosyl-(1→2)[α-rhamnopyranosyl-(1→6)]-β-galactopyranoside (mauritianin) (5), isorhamnetin-3-O-α-rhamnopyranosyl-(1→2)[α-rhamnopyranosyl-(1→6)]-β-galactopyranoside (6), kaempferol-3-O-α-rhamnopyranosyl-(1→6)]-β-glucopyranoside (nikotiflorin) (7) and isorhamnetin-3-O-α-rhamnopyranosyl-(1→6)]-β-glucopyranoside (narcissin) (8) . The structures of the isolated compounds were established by means of 2D NMR experiments, HPLC-DADMS, HR-MS and UV spectral analyses. Pivotal role in the structure elucidation and in particular in the determination of sugar sequence, played HSQC-TOCSY and ROESY experiments whereas those of the known compounds (2–8) were established by spectral comparison with those published in the literature.