A new xenicane norditerpene from the Indian marine gorgonianAcanthogorgia turgida

New secondary metabolite with cytotoxicity from spawning soft coral Asterospicularia laurae in Taiwan

We have conducted a long-term research on the Taiwanese soft coral Asterospicularia laurae, which resulted in many xenicane-type diterpenoids such as asterolaurins A-M from A. laurae coral tissues during the non-spawning period were isolated. Here, we report a new xenicane diterpenoid, asterolaurin N (1), along with three known xenicane-type monocarbocyclic diterpenes [13-epi-9-desacetylxenicin (2), xeniolide-B 9-acetate (3) and asterolaurin I (4)] from A. laurae during the spawning period. The structures of the new secondary metabolite were established with an extensive spectroscopic analysis. The 1D and 2D nuclear magnetic resonance (NMR) data of the compounds were discussed. We discovered that the C-15 of 1 contains two methyl groups on a carbon bearing an acetyl group, which has not been reported previously. In addition, Compounds 1, 3, and 4 showed selective cytotoxic activity against Molt 4, while 2 exhibited significant cytotoxicity against Molt 4, K562, Sup-T1 and U937 cell lines.

Isolation and Antifouling Activity of Azulene Derivatives from the Antarctic Gorgonian Acanthogorgia laxa

Three azulenoid sesquiterpenes (1 - 3) were isolated from the Antarctic gorgonian Acanthogorgia laxa collected by bottom trawls at -343 m. Besides linderazulene (1), and the known ketolactone 2, a new brominated C₁₆ linderazulene derivative (3) was also identified. This compound has an extra carbon atom at C(7) of the linderazulene framework. The antifouling activity of compounds 1 and 2 was assayed in the laboratory with Artemia salina larvae, and also in field tests, by incorporation in soluble-matrix experimental antifouling paints. The results obtained after a 45 days field trial of the paints, showed that compounds 1 and 2 displayed good antifouling potencies against a wide array of organisms. Compound 3, a benzylic bromide, was unstable and for this reason was not submitted to bioassays. Two known cembranolides: pukalide and epoxypukalide, were also identified as minor components of the extract.