Saponins from Chinese cucurbitaceous plants: Solubilization of saikosaponin-a with hemslosides Ma2 and Ma3 and structure of hemsloside H1 from Hemsleya chinensis.

Abstract

It was found that the water solubility of saikosaponin-a (8), a pharmacologically active saponin of Bupleuri radix, was significantly increased in the presence of hemslosides Ma2 (2) and Ma3 (3), bisdesmosides of oleanolic acid (9) isolated from a Chinese folk medicine, rhizomes of Hemsleya macrosperma (Cucurbitaceae). The structure of a new saponin named hemsloside H1 (7), isolated from rhizomes of H. chinensis together with several known saponins, was elucidated to be β-gentiobiosyl oleanolate 3-O-[β-glucopyranosyl-(1→2)]-[α-arabinopyranosyl-(1→3)]-β-glucopyranouroside.