Brianodins A-D, briarane-type diterpenoids from soft coral Pachyclavularia sp.

Four new briarane-type diterpenoids, brianodins A-D (1-4), were isolated from a soft coral, Pachyclavularia sp., and the structures and relative stereochemistry of 1-4 were elucidated on the basis of spectroscopic data. The absolute configurations of 3 and 4 were assigned by the MTPA method. Brianodin A (1) showed a modest cytotoxicity.