文摘
Six new C21 steroidal glycosides, cynotophyllosides A鈥揊 (1鈥?b>6), together with 16 known compounds, were isolated from the roots of Cynanchum otophyllum. The structures of the new compounds were elucidated by spectroscopic analysis and chemical methods. The three major components, otophylloside F (15), otophylloside B (17), and rostratamine 3-O-尾-d-oleandropyranosyl-(1鈫?)-尾-d-cymaropyranosyl-(1鈫?)-尾-d-cymaropyranoside (18), suppressed the seizure-like locomotor activity caused by pentylenetetrazole in zebrafish. Preliminary structure鈥揳ctivity relation studies revealed that a pregnene skeleton with a C-12 ester group (ikemaoyl > cinnamoyl > hydroxy > p-hydroxybenzoyl) and a C-3 sugar chain consisting of three 2,6-dideoxysaccharide units is essential for this suppressive activity.