A New Saponin from the Seeds of Zizyphus jujuba var. spinosa

摘要

Sour jujube (Zizyphus jujuba Miller var. spinosa Hu ex H. F. Chou) is a thorny, rhamnaceous deciduous plant distributed widely throughout tropical and subtropical regions. The dried seeds are named sanjoin (Zizyphi Spinosi Semen) in Korean and have a thousand-year history of use in traditional medicine as a sedative for treating mild anxiety, nervousness and sleep-related problems.1 Previous phyto-chemical investigations on the seeds of this plant have resulted in the isolation of saponins, flavone C-glyco-sides, cyclopeptide alkaloids, triterpenoids, and others. These compounds exhibit multiple activities, such as hypnotic, histamine-release inhibitory, anti-inflammatory and sedative, inhibition of foam cell formation, adjuvant, and cardiotonic effects. Our previous studies focused on isolating the flavonoid-C-glycosides and the sedative activities of these flavonoids. In the continuing search for new chemicals and biomarkers from Z jujuba var. spinosa for quality control studies of related herbal medicines, 8 flavonoids, along with 3 other known components, were isolated. In the present investigation, we report the isolation and structural elucidation of a new saponin, named jujuboside A2 (1), together with three known saponins, zizyphus saponin III (2), jujuboside B (3), jujuboside A (4), and a known sesquiterpene glucoside, dihydrophaseic acid 3-0-β-D-glucopyranoside (5), from the seeds of Z jujuba var. spinosa.