Steroidal triglycosides, kurilensosides A, B, and C, and other polar steroids from the Far Eastern starfish Hippasteria kurilensis.

Three novel steroidal triglycosides, designated as kurilensosides A, B, and C (1- 3), were isolated along with a new steroidal diglycoside, kurilensoside D (4), and two new (6, 7) and one known (5) polyhydroxysteroid from the alcoholic extract of the Far Eastern starfish Hippasteria kurilensis. Compounds 1-3 are the first triglycosides containing two carbohydrate chains found from starfish. The structures of 1-7 were elucidated by spectroscopic methods (mainly 2D NMR) and chemical derivatization. Glycosides 1-4 and steroids 6 and 7 inhibited sea urchin egg fertilization by sperm preincubated with these compounds.