Cembranoids from the Soft Coral Sinularia rigida with Antifouling Activities

Chemical examination of the soft coral Sinularia rigida resulted in the isolation of 12 new cembranoids, namely, sinulariols T-Z(5) (1-12), together with a known analogue, 13. Their structures were determined on the basis of ID and 2D NMR (COSY, HSQC, HMBC, and NOESY) spectroscopic analyses in association with MS and IR data. Compounds 7 and 13 showed potent antifouling activity for the inhibition against the barnacle Balanus amphitrite and moderate inhibition against Bugula neritina. The primary structure-activity relationship is discussed.