In order to discover new bioactive compounds, the chemical constituents from the organic extracts of the cultured soft coral Klyxum simplex and wild-type soft coral Cladiella hirsute were studied. 27 new eunicellin-based diterpenoids, klysimplexins A¡VX (1¡V24) and klysimplexin sulfoxides A¡VC (25¡V27), were isolated from a cultured soft coral Klyxum simplex. Furthermore, eight new eunicellin-base diterpenoids, hirsutalins C (28) and F¡VL (29¡V35), were isolated from the soft coral Cladiella hirsuta. The structures of compounds 1¡V35 were elucidated by spectroscopic methods, in particular 1D and 2D NMR experiments. The absolute stereochemistries of 1, 3, 12, and 22 were determined by Mosher¡¦s method. The structure of 1 was further confirmed by a single-crystal X-ray diffraction analysis. The absolute configurations of 1, 3, 12, and 22 were determined by Mosher¡¦s method. Compounds 2, 8, 17, 20, and 29 have been shown to exhibit cytotoxicity toward a limited panel of cancer cell lines. Compounds 10¡V14, 18, 19, 25¡V28, and 31 were found to display significant in vitro anti-inflammatory activity in LPS-stimulated RAW264.7 macrophage cells by inhibiting the expression of the iNOS protein. Compounds 18, 19, and 27 also could effectively reduce the level of the COX-2 protein.

In order to discover for bioactive compounds, we have studied the chemical constituents from the organic extracts of soft coral Klyxum molle. This study had led to the isolation of 16 eunicellin-type diterpenoids, including ten new compounds, klymollins A¡VJ (1¡V10), along with six know compounds 11¡V16. The structures of compounds 1¡V16 were established by spectroscopic methods and by comparison of the spectral data with those of the related known compounds. It is noteworthy to mention that compounds 1¡V10 represent the first example of eunicellins possessing a C-11/C-17 epoxide. The absolute configuration of 4 was determined using a modified Mosher¡¦s method. The cytotoxicity of compounds 1¡V8 and 11¡V16 against the A549 (human lung epithelial cells), HepG2 (human hepatocellular carcinoma), Hep3B (human hepatocellular carcinoma), MCF-7 (human breast adenocarcinoma)¡BMDA-MB231 (human breast adenocarcinoma) tumor cell lines were determined. Compound 11 showed cytotoxicity toward A549 tumor cells (IC50 value of 3.14 £gg/mL) and compounds 15 and 16 were found to exhibit cytotoxicity toward HepG2 tumor cell (IC50 values of 3.82 and 2.50 £gg/mL). Compounds 6 and 7 were found to show significant activity against the accumulation of the pro-inflammatory iNOS and COX-2 protein at 1 £gM.

Eighteen eunicellin-based diterpenoids were isolated from the organisms of the soft coral Cladiella krempfi. According to the results of 1D and 2D NMR spectroscopic experiments, the structures of these marine natural products were established. Among them, krempfielins A¡VJ (1¡V10) are new compounds, and sclerophytin B (11), sclerophytin F (12), litophynols A (13), (1R*, 2R*, 3R*, 6S*, 7S*, 9R*, 10R*, 14R*)-3-butanoyloxycladiell-11(17)-en-6,7-diol (14), litophynin I monoacetate (15), (1R*, 2R*, 3R*, 6S*, 9R*, 10R*, 14R*)-3- acetoxycladiell-7(16)-11(17)-dien-6-ol (16), 6-acetoxy litophynin E (17) and litophynin F (18) are the previously isolated compounds. The anti-inflammation activity of these compounds at 10 £gM was studied. The results showed that 9, 14 and 17 effectively inhibited more than 80% expression of iNOS protein in LPS stimulated RAW 264.7 macrophage cells, and 5, 6, 10, 13 and 18 inhibited more than 60% expression of iNOS protein. Also, 9, 12, 16 and 18 were found to inhibit the expression of COX-2 protein in LPS stimulated RAW 264.7 macrophage cells to 52.5, 79.2, 82.2 and 48.2%. Cytotoxicity of these compounds were tested by the MTT assay using five human cancer cell lines (A549, BT483, H1299, Hep3B and SAS) and one normal cell line, BEAS2B. Compounds 9, 10, 11, 14, 17 and 18 were shown to exhibit cytotoxic activity.

Chemical investigation of the soft coral Cladiella hirsuta, collected off the coast of Penghu Islands, has led to the isolation of natural products including ten new compounds hirsutalins A-D (1, 2, 3, 5) and hirsutosterols A-F (6, 7, 8, 9, 10, 11), and one known compound 3-butanoyloxycladiell-11(17)-en-6,7-diol (4). All of the chemical structures were established by detailed spectral data analysis (NMR, IR, MS) and by comparison of the spectral data with those of the related known compounds. The absolute structure of compound 1 was determined applying a modified Mosher¡¦s method. On the part of the cytotoxicity assay with six human cancer cell lines, HepG2 (liver cancer cell), Hep3B (liver cancer cell), Ca9-22 (mouth cavity cancer cell), A549 (lung cancer cell), MCF7 (breast cancer cell) and MDA-MB-231 (breast cancer cell), compound 5 showed the significant cytotoxicity against the cancer cell line HepG2; compound 7 showed the moderate cytotoxicity against all of the above cancer cell lines; compounds 6, 8 and 10 also showed the moderate cytotoxicity against two of them, Hep3B and Ca9-22. The products 6a and 7a , obtained by hydorlysis of 6 and 7, respectively, did not show obvious difference in cytotoxity by comparison of the IC50 values of compounds 6 and 7. On the part of anti-inflammation assay, compound 2 showed the effectively inhibiting activity against the induced iNOS and COX-2 proteins. Compound 3 showed nearly the same activity against the induced iNOS protein as that of 2.

In order to discover marine bioactive compounds, we investigated the chemical constituents from the organic extracts of soft coral Klyxum molle. Repeated column chromatography on the ethyl acetate extract of soft coral Klyxum molle, resulted in the isolation of nine new eunicellin-type diterpenoids, klymollins V¡ÐZ (1¡Ð5) and klyxumollins A¡ÐD (6¡Ð9), and four known compounds (10¡Ð13). The structures of new compounds were determined on the basis of extensive spectroscopic data (IR, MS, 1D and 2D NMR) and by comparison of the spectral data with those of the related known compounds. The cytotoxicity of compounds 1¡Ð13 was evaluated against five tumor cell lines including CCRF-CEM (human T cell lymphoblast-like cell line), K562 (human erythromyeloblastoid leukemia cell line), Molt 4 (human acute lymphoblastic leukemia cell line), T47D (human ductal breast epithelial tumor cell line) and DLD-1 (human colorectal adenocarcinoma cell line). Compound 2 exhibited weak cytotoxicity toward three cancer cells (CCRF-CEM, Molt 4 and T47D) and compounds 4 and 9 showed weak cytotoxicity against CCRF-CEM cancer cells. Compound 11 was found to exhibit stronger cytotoxicity toward CCRF-CEM cancer cells (ED50 values of 4.2 £gg/mL). On the other hand, compound 3 showed weak activity against the accumulation of the pre-inflammatory cytokine IL-6 in LPS-induced macrophages, at a concentration of 25 £gM.

Seven new eunicellin-based diterpenoids, krempfielins K¡ÐQ (1¡Ð7), along with six known compounds, litophynin I (8), krempfielin A (9), krempfielin D (10), sclerophytin F (11), litophynol B (12), and litophynol I monoacetate (13), have been isolated from the soft coral Cladiella krempfi which was collected from Penghu Island of Taiwan. Their structures were determined through extensive spectroscopic data (IR, MS, 1H NMR, 13C NMR, HSQC, HMBC, COSY, and NOESY) and by comparison of the spectral data with those of the related known compounds. The structure of compound 1 is rare due to the presence of a tetrahydropyran ring constituted from C2¡ÐC6 and oxygen atom. Compound 7 is the first discovery of eunicellin-based dimer. The anti-inflammation activity of twelve compounds (1¡V6 and 8¡V13) at 10 £gM was studied. The results showed that compound 4 inhibited more than 70% express of elastase released in FMLP/CB-induced human neutrophils .

In order to search for bioactive compounds, we have studied the chemical constituents from the organic extracts of one soft corals Klyxum simplex and two gorgonians Subergorgia mollis and Briareum excavatum. This study had led to the isolation of twenty-seven natural compounds 1¡V27, including nineteen new eunicellin¡Vtype diterpenoids, simplexins A¡VS (1¡V19) from K. simplex, one new steroid 11£\,15£\-diacetoxy-17£]-pregna-4,20- dien-3-one (20) along with one known compound 17£]-pregna-4,20-dien-3- one (21) from S. mollis, and six new briarane¡Vtype diterpenoids briaexcavatolides Q (22), S¡VV (23-26) and W (27) from B. excavatum. The structure of these compounds were established by the detailed spectroscopic analysis (IR, MS, 1D¡B2D NMR) and by comparison of the physical and spectral data with those of the related known compounds. The absolute configuration of 1 was determined by using a modified Mosher's method. The cytotoxicity of compounds 1¡V6, 9, 13¡V15 against the MCF-7 (human breast adenocarcinoma), Hep2 (human laryngeal carcinoma), Daoy (human medulloblastoma), and Hela (human cervical epitheloid carcinoma) cancer cell lines were determined. Compounds 1, 4 and 14 showed weak inhibition against the growth of MCF-7, Hep2 and Daoy, but did not inhibit the growth of Hela cells. Compound 5 exhibited a weak cytotoxicity against the growth of MCF-7, Hep2, Hela and Daoy cells. In addition, the activity of compounds 1¡V6, 9, 13¡V15 to inhibit the pro-inflammatory iNOS and COX-2 protein expression in LPS-stimulated RAW264.7 macrophage cells was estimated. Compound 5 showed the best anti-inflammatory activity among the all tested compounds.