In order to search for bioactive compounds, we have studied the chemical constituents from the organic extracts of the soft coral Sarcophyton crassocaule. This study had led to the isolation of twenty-six natural cembrane-type diterpenoids, compounds 1¡V26, including eighteen new compounds, sarcocrassocolide A¡VR (1¡V18), along with six know compounds, crassocolide A, B, D, E, L, sarcocrassolide, sinularolide E and 13-acetoxysarcocrassolide (19¡V26). The structures of compounds 1¡V26 were established by detailed spectroscopic data analysis (IR, MS, 1D, 2D NMR) and by comparison of the spectral data with those of the related known compounds. The structures of 8, 9 and 11 were further established by orgamic methods, and the absolute configuration of 1 was determined using a modified Mosher¡¦s method. The cytotoxicity of compounds 1¡V17 and 19¡V21 against the Daoy (human medulloblastoma), HEp2 (human laryngeal carcinoma), MCF-7 (human breast adenocarcinoma), WiDr (human colon adenocarcinoma), DLD-1 (human colon adenocarcinoma), CCRF-CEM (human T-cell acute lymphoblastic leukemia), and HL-60 (human promyelocytic leukemia) tumor cell lines were determined, and structure-activity relationship was presented by statistic method. Compounds 3 and 9 showed significant activity toward the above Daoy, HEp2, MCF7 and WiDr, and compounds 18, 19, 20, 22 and 24 were found to show significant activity toward the above DLD-1, CCRF-CEM and HL-60. Compounds 1¡V26 were shown to exert significant anti-inflammatory activity in LPS-stimulated RAW264.7 macrophage cells. Compounds 9, 17, 19, 22 and 24 also significantly inhibited the accumulation of pro-inflammatory COX-2 protein.

Chromatographic purification of a methylene chloride extract of Formosan soft coral Sarcophyton crassocaule (collected in Green island) led to the isolation of two new (1S*, 3R*, 4R*, 7E, 11E, 14R*)-3, 4-epoxycembra-7, 11, 15-trien-1, 14-olide (1) and (1R*, 3E, 7E,11R*, 12S*, 14R*)-11, 12-epoxycembra-3, 7, 15-trien-1, 14-olide (2) isomeric diterpenoids , a known cyclic peroxide diterpenoid (1R*, 2S*, 3E, 7S*, 8R*, 11S*, 12Z)-8, 11-epidioxy-7-acetoxycembra-3, 12, 15-trien-1, 2-olide (3), as well as two known (24S)-24-methylcholestane-3b, 5a, 6b-triol (4) and 24x-methyl-cholestane -3b, 5a, 6b, 25-tetrol 25-monoacetate (5) steroids. Chromatographic fractionation of a methylene chloride extract of two Formosan soft corals Sarcophyton elegans (collected in Green island) led to the isolation of a known 24x-methylcholestane -3b, 5a, 6b, 25-tetrol 25-monoacetate (5) steroid, the methylene chloride extract of Sarcophyton trocheliophorum, on the other hand, afforded a known diterpenoid, (+)-isosarcophine (6). Purification of a methylene chloride extract of Octocorallia soft coral (unidentified) led to the isolation of two known steroids, cholesterol (7) and (22E, 24S)-24-methylcholesta-5, 22-dien-3b-ol (8). Compounds 1-7 exhibited cytotoxicity against P388 cancer cell line. Compounds 2 and 5 were active against HT-29 cancer cell line.

The methylene chloride extracts of Formosan soft coral Sarcophyton crassocule Von. Marenzeller (collected at Green Island off Taiwan) were found to exhibit significant cytotoxicity against P-388, HT-29, and A-549 cancer lines. Chromatographic separation led to the isolation of three known cembrane diterpenoids, GN16-34 (1), GN16-35 (2), GN16-40 (3), and a new cembrane, GN16-62 (4). The methylene chloride and acetone extracts of Formosan soft coral Xenia puerto-galerae Roxas (collected at Green Island off Taiwan) were found to exhibit significant cytotoxicity against P-388 and A-549 cancer cell lines. Chromatographic separation resulted in the isolation of six new cadinane sesquiterpenes, GN44-28 (5), GN44-30 (6), GN44-44 (7), GN44-66 (8), GN44-173 (9), GN44-149 (10), and one known dicarbocyclic diterpenes with a bicyclic [4.3.1] ring system, GN44-199 (11). Compounds 3 and 4 exhibited significant cytotoxicity against P-388, HT-29, and A-549 cancer cell lines. Compounds 1 and 2 exhibited significant cytotoxicity against P-388 cancer cell lines. Compounds 5 and 7 exhibited significant cytotoxicity against A-549 cancer cell line. compound 10 exhibited significant cytotoxicity against P-388 and A-549 cancer cell lines.