Triterpenoid Saponins from the Roots of Sophora koreensis

From the roots of Sophora koreensis (Fabaceae), three new oleanene-type triterpene glycosides, echinosophorosides A1 (1) and B (2), and acetyl-subproside II (5), were isolated as their methyl esters, together with the four known ones sophoraflavoside I, kudzusaponin SA3, subproside II, and azukisaponin V. The structures of the new saponins were elucidated to be 3-O-α-L-rhamnopyranosyl(1→2)-α-L-arabinopyranosyl(1→2)-β-D-glucuronopyranosyl...