A New Spiroketal Steroid from Gorgonella Umbraculum

A new spiroketal steroid ( 2 ) was isolated from the Indian Ocean gorgonian, Gorgonella umbraculum besides the known briarane diterpenoids, juncellin, umbraculides A and D. The new steroid was characterised as 22-acetoxy-3,25-dihydroxy-16-24,20-24-bisepoxy-(3 g , 16 f , 20 S , 22 R , 24 S )-cholest-5-ene ( 2 ) by a study of its spectral data.