Flavonol glycosides from aerial parts of Astragalus thracicus Griseb

Five flavonol glycosides, including a new glutaryl-conjugated compound, were isolated from methanolic extract of the endemic Balkan species Astragalus thracicus Griseb. Based on NMR and MS spectra, one new compound was identified as kaempferol 3-O-[v-glucopyranosyl-(1RT4)-a-rhamnopyranosyl-(1RT6)-(2"-3-hydroxy-3-methylgutaroyl)-v-galactopyranoside)] (1). The other compounds, all known, were identified as mauritianin (2), kaempferol-3-O-a-l-rhamnopyranosyl-(1RT2)-v-galactopyranoside (3), kaempferol-3-O-v-apiofuranosyl-(1RT2)-v-galactopyranoside (4), and quercetin-3-O-v-apiofuranosyl-(1RT2)-v-galactopyranoside (5). All of them, except 2, were found for the first time in a representative of genus Astragalus.