Diterpenoids, norditerpenoids, and secosteroids from the Formosan soft coral Cespitularia hypotentaculata.

Four new cespitularane diterpenes, cesputularins I-L (1-4), two new norverticillane norditerpenes, cespitularins M and N (5 and 6), two new verticillane diterpenes, cespitularins O and P (7 and 8), a new norditerpene, cespitularin Q (9) (having a novel carbon skeleton), a new xenicane diterpene, cespitolide (10), and two new secosteroids, 3beta,11-dihydroxy-5beta,6beta-epoxy-9,11-secocholestan-9-one (11) and 3beta,11-dihydroxy-5beta,6beta-epoxy-9,11-secogorgostan-9-one (12), were isolated from the methylene chloride solubles of the Formosan soft coral Cespitularia hypotentaculata Roxas. The structures were elucidated by extensive spectroscopic analysis, and their cytotoxicity against selected cancer cells was measured in vitro.