Flavonol glycosides from aerial parts of Astragalus thracicus Griseb

[Display omitted] •Phytochemical research was performed on Astragalus thracicus.•Five flavonoids from the Balkan Astragalus species were obtained and identified.•A new flavonoid containing a 3-hydroxy-3-methylglutaryl group was identified. 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-[β-glucopyranosyl-(1→4)-α-rhamnopyranosyl-(1→6)-(2"-3-hydroxy-3-methylgutaroyl)-β-galactopyranoside)] (1). The other compounds, all known, were identified as mauritianin (2), kaempferol-3-O-α-l-rhamnopyranosyl-(1→2)-β-galactopyranoside (3), kaempferol-3-O-β-apiofuranosyl-(1→2)-β-galactopyranoside (4), and quercetin-3-O-β-apiofuranosyl-(1→2)-β-galactopyranoside (5). All of them, except 2, were found for the first time in a representative of genus Astragalus.