Oxygenated cembranoids of the decaryiol type from the Indonesian soft coral Lobophytum sp.

Three novel cembrane diterpenoids, decaryiols B–D (5–7), characterized by a bicyclic skeleton of the decaryiol-type, have been isolated from the Indonesian soft coral Lobophytum sp., along with three known cembranoids. The stereostructures of these metabolites have been established through extensive NMR spectroscopic analysis, application of the modified Mosher method, and chemical conversion. Cembranoids obtained from Lobophytum sp. (2–7) and six semisynthetic derivatives (9–14) prepared from decaryiol were tested for cell growth inhibitory activity against three different cell lines. O-Methyl decaryiol (10) exhibited a significant and selective activity against glioma cell lines.