Cynanauriculoside C-E, three new antidepressant pregnane glycosides from Cynanchum auriculatum

Article abstract of DOI:10.1016/j.phytol.2011.02.009

Based on the bioactive screening results, three new pregnane glycosides named as cynanauriculoside C-E (1-3), were isolated from the roots of Cynanchum auriculatum Royle ex Wight (Asclepiadaceae), together with two known ones, otophylloside L (4) and cynauricuoside C (5). On the basis of detailed spectroscopic analysis and chemical method, the structures of new compounds were characterized to be qingyangshengenin 3-O-β-d-oleandropyranosyl-(1 → 4)-β-d-cymaropyranoside (1), qingyangshengenin 3-O-β-d-glucopyranosyl- (1 → 4)-β-d-glucopyranosyl-(1 → 4) -α-l-cymaropyranosyl-(1 → 4)-β-d-oleandropyranosyl-(1 → 4)-β-d-cymaropyranoside (2) and caudatin 3-O-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-β-d-cymaropyranosyl-(1 → 4)-β-d-oleandropyranosyl-(1 → 4)-β-d-digitoxopyranoside (3). In the despair mice models, these pregnane glycosides showed significant antidepressant activity at the dosage of 50 mg/kg (i.g.). The most potent one was cyanauriculatoisde D (2), which was close to the positive control fluoxetine (20 mg/kg).