Four new flavonol glycosides from the leaves of Astragalus caprinus.

Four new flavonol 3-O-glycosides were isolated from the leaves of Astragalus caprinus. Their structures were elucidated by spectroscopic methods as rhamnocitrin-3-O-{[3-hydroxy-3-methylglutaroyl(1→6)][β-d-apiofuranosyl(1→2)]}-β-d-galactopyranoside (1), rhamnetin-3-O-{[3-hydroxy-3-methylglutaroyl(1→6)][β-d-apiofuranosyl(1→2)]}-β-d-galactopyranoside (2), kaempferol-3-O-[β-d-xylopyranosyl(1→3)-α-l-rhamnopyranosyl(1→6)]-β-d-galactopyranoside (3), and quercetin-3-O-{[β-d-xylopyranosyl(1→3)-α-l-rhamnopyranosyl(1→6)][β-d-apiofuranosyl(1→2)]}-β-d-galactopyranoside (4).