Flavonoid constituents and biological screening of Astragalus bombycinus Boiss.

Two new flavonoid compounds were isolated from Astragalus bombycinus Boiss. and identified as quercetin-3,7-di-O-β-glucopyranoside 4'-O-α-rhamnopyranoside and 5,2',4'-trihydroxy-flavone-8-C-α-arabinopyranoside-7-O-β-glucopyranoside. In addition, apigenin, apigenin-7-O-β-glucopyranoside, apigenin 7-O-gentobioside, luteolin, luteolin-7-O-β-glucopyranoside, quercetin-3,7-di-O-β-glucopyranoside, quercetin-3-O-β-glucopyranoside-7-O-α-rhamnopyranoside and daidzein were also isolated and identified. The structure elucidation of the isolated compounds was performed by chromatographic, chemical and spectroscopic methods. Antioxidant and cytotoxic activities were also determined for the four consecutive extracts of the plant.