Terpenoids from the Soft Coral Stereonephthya bellissima .

A detailed chemical study of the extract from the soft coral Stereonephthya bellissima resulted in the isolation and identification of seven new sesquiterpenoids, bellissinanes A-G ( 1 - 7 ), along with four new diterpenes ( 8 - 11 ). Bellissinane A ( 1 ) is the third reported nardosinane-type sesquiterpene bearing a 6/5/6 tricyclic system. Bellissinanes C and D ( 3 , 4 ) contain a phenylethylamine fragment, which is relatively unusual in marine organisms. Bellissinanes E-G ( 5 - 7 ) belong to the rare class of nornardosinane sesquiterpenoids. Structurally uncommon octahydro-1 H -indenyl-type and prenyleudesmane-type skeletons were characterized for herpetopanone B ( 8 ) and bellissimain A ( 9 ), respectively. Bellissinane E ( 5 ) exhibited in vivo angiogenesis-promoting activity.