[C21 steroids from roots of Cynanchum otophyllum].

Eleven C21 steroids were isolated from chloroform extract of roots of Cynanchum otophyllumby silica gel, MCI, ODS columns, and semi-preparative HPLC. Their structures were determined by spectroscopic data analysis as otophylloside B(1), caudatin-3-O-beta-D-cymaropyranosyl-(1-->4)-beta-D-oleandropyranosyl-(1-->4)-beta-D-cymaropyranosyl-(1-->4)-beta-D-cymaropyranoside (2), caudatin-3-O-beta-D-oleandropyranosyl-(1-->4)-beta-D-oleandropyranosyl-(1-->4)-beta-D-cymaropyranosyl-(1-->4)-beta-D-cymaropyranoside (3), caudatin-3-O-beta-D-oleandropyranosyl-(1-->4)-beta-D-digitoxopyranosyl-(1-->4)-beta-D-cymaropyranoside (4), otophylloside O (5), gagamine-3-O-beta-D-oleandropyranosyl-(1-->4)-beta-D-cymaropyranosyl-(1-->4)-beta-D-cymaropyranoside (6), sinomarinoside B (7), mucronatosides C (8), wallicoside J (9), stephanoside H (10), and qinyangshengenin-3-O-beta-D-oleandropyranosyl-(1-->4)-beta-D-cymaropyranosyl-(1-->4)-beta-D-digitoxopyranoside (11). Among them, compounds 2-3, and 6-11 were separated from the roots of this plant for the first time.