Xenimanadins A-D, a family of xenicane diterpenoids from the Indonesian soft coral Xenia sp.

Four novel xenicane diterpenoids, xenimanadins A-D (1-4), characterized by the unusual 2,6-dimethoxytetrahydropyran functionality, have been isolated from the Indonesian soft coral Xenia sp., together with three known xeniolides. The stereostructure of these metabolites has been established through extensive interpretation of NMR data and application of the modified Mosher method. Xenimanadins were tested against tumor cell lines, revealing details about the cytotoxic potential of xenicane diterpenoids.