Pregnane glycosides from the antidepressant active fraction of cultivated Cynanchum otophyllum.

Based on the bioactive screening results, four new pregnane glycosides, namely cynanotophyllosides A-D (1-4) were isolated from the anti-depressant active fraction of cultivated Cynanchum otophyllum, along with thirteen known compounds (5-17). The new compounds were characterized as qingyangshengenin 3-O-β-D-glucopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside (1), qingyangshengenin-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→4)-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-α-L-cymaropyranosyl-(1→4)-β-D-cymaropyranoside (2), caudatin-3-O-β-D-glucopyranosyl-(1→4)-β-D-thevetopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-digitoxopyranoside (3) caudatin-3-O-β-D-glucopyranosyl -(1→4)-β-D-thevetopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside (4), by detailed spectroscopic analysis and acidic hydrolysis.