Cytotoxic cembranoid diterpenes

A new epoxy-bridged cembranoid diterpene 49 possessing antifouling activity was reported from an unidentified Thai soft coral species of the Sarcophyton genus, whose structure was assigned by NMR and NMR experiments. Two new cembranoids, 50 and 51, which showed cytotoxic activity on ehrlichacities tumor... 

Again, soft corals and gorgonians are a rich source of diterpenoids of 19 structural classes, some of which are specific to them (35, 36). Besides tobacco plants, cembranoid diterpenes are limited to soft corals. Lophotoxin (126) isolated from sea whips of the genus Lophogorgia is a sodium channel inhibitor (3). Xenicin (127) from the soft coral Xenia elongata and briarein A (128) from the gorgonian Briareum asbestinum represent non-cembranolide diterpenes. Diterpenoids of these classes show antimicrobial, cytotoxic, and insecticidal activities. 

Compound 9 is one example of a series of mebabolites of cembranoid diterpenes from the soft coral Sarcophyton trocheliophorum. The compounds are mildly cytotoxic and represent modifications of the antitumor promoter sarcoph-ytol A. Bis-esters with MPA were prepared, and the stereocenters at C7 and C14 were assigned on the basis of AS values in the H NMR spectmm. ... 

Li, G., Zhang, Y, Deng, Z., van Oftvegen, L., Proksch, P., and Lin, W. (2005h) Cytotoxic cembranoid diterpenes from a soft coral Sinularia gibberosa. J. Nat. Prod., 68, 649-652. 

---