Novel diterpenoids from the Indian Ocean soft coral Sarcophyton elegans

Chemical examination of the soft coral species Sarcophyton elegans collecte d from the Havelock Island of the Andaman and Nicobar group of Islands of t he Indian Ocean resulted in the isolation of four novel diterpenoids, sarco phytin (1), 7-dehydrosarcophytin (2), Delta(7(15))-dehydrosarcophytin (3) a nd isosarcophytin (4) along with some known compounds. The structures of th e new diterpenoids were established by the help of their physical and spect ral data including X-ray analysis on sarcophytin (1). The known compounds a re Delta(9(15))-africanene (5), methyl arachidonate (6), (24S)-24-methylcho lestane-3 beta,25-diol (7), batyl alcohol (8), (24S)-24-methylcholestane-1 beta,3 beta,5 alpha,6 beta,25-pentol (10), its 25-monoacetate (9), three mo nohydroxy sterols 4 alpha,24-dimethylcholestan-3 beta-ol (11a), 4 alpha,23 xi,24 xi-trimethylcholestan-3 beta-ol (11b) and 23 xi-ethyl-4 alpha,24 xi-d imethylcholestan-3 beta-ol (11c) as a mixture.