The soft corals of the species Paralemnalia thyrsoides was found to be a rich source of sesquiterpenoids, such as nor-nardosinane, nardosinane, neolemnane, and eremophilane, and other related skeletons. Continuing investigation on the chemical constituents of Paralemnalia thyrsoides has led to the isolation of nine new compounds, including one dinor-nardosinane 1, one neolemnane 2, five nardosinanes 4, 6¡V9, and two nor-nardosinanes 10 and 11, along with eleven known compounds, 2-deoxy-7-O-methyllemnacarnol (3), 2-deoxy-12£\-methoxy-7-O-methyllemnacarnol (5), paralemnolin Q (12), paralemnolin R (13), 4-acetoxy-2,8-neolemnadien-5-one (15), paralemnolin E (16), flavalins E (17), isoparalemnanone (18), paralemnolin K (19), and nor-nardosinane sesquiterpenoids (14 and 20). The structures of these compounds were determined on the basis of their spectroscopic analysis (1H, 13C NMR, 1H¡V1H COSY, HSQC, HMBC, IR and HRESIMS) and by comparison of the physical and spectral data with those of the related known compounds. The relative stereochemistry and assignments of 1H NMR chemical shifts were determined by NOESY and coupling constants. The absolute stereochemistry of dinor-nardosinane 1 was further determined by application of the Mosher¡¦s method. The cytotoxicity against of P-388 (murine lymphocytic leukemia), HT-29 (human colon adenocarcinoma), and A-549 (human lung epithelial carcinoma) cells as well as the anti-HCMV (human cytomegalovirus) activities of metabolites 1, 2, 4, 6¡V11 were evaluated. Metabolites 2, 3, 5, 6, 8 and 9 exhibited significant activity against P-388 cell in vitro ( ED50 ¡Ø 4 £gg/ mL) Keywords: Paralemnalia thyrsoides, sesquiterpenoids, cytotoxicity, anti-HCMV

Previous studies on the secondary metabolites of Formosan octocoral Isis hippuris were collected only at Green Island. In the course of our studies on secondary metabolites from marine organisms, the acetone-solubles of the Formosan octocoral Isis hippuris collected at Orchid Island has led to the isolation of eleven polyoxygenated steroids (1¡V11), along with two known compounds (12 and 13). The structures of these compounds were determined on the basis of their spectroscopic and physical data, including NMR, IR, MS, etc. The cytotoxicity against of A-549 (human lung epithelial carcinoma), HT-29 (human colon adenocarcinoma), and P-388 (mouse lymphocytic leukemia) cells, and anti-HCMV (human cytomegalovirus) activity of metabolites 1¡V13 were evaluated. Compounds 12 and 13 displayed cytotoxicity against P-388 cell line with ED50 values of 3.2 and 3.6 £gg/mL, respectively. Compound 12 exhibited cytotoxicity against A-549 cell line with an ED50 value of 3.8 £gg/mL. Compound 8 exhibit inhibitory activity against HCMV, with EC50 values of 2.0 £gg/mL.

Numerous bioactive secondary metabolites including sesquiterpenoids,diterpenoids, meroditerpenoids, and steroids have been isolated from the soft corals of the genus Nephthea. In order to search for novel bioactive substances from marine organisms, we have investigated the secondary metabolites of the organic extract of the soft coral Nephthea chabrolii collected at San-Hsian-Tai. Chromatographic fractionation of the acetone-soluble has led to the isolation of four 19-oxygenated steroids 1¡V4 and two 19-norergosterols 5, 6, along with twelve known compounds 7¡V18. The structures of these compounds were determined on the basis of their spectroscopic analysis data (1H NMR, 13C NMR, 1H¡V1H COSY, HSQC, HMBC, NOESY, IR, and HRESIMS), physical data and compared with the literature data. The cytotoxicity against of A-549 (human lung epithelial carcinoma), HT-29 (human colon adenocarcinoma), and P-388 (mouse lymphocytic leukemia) cells, and anti-HCMV (human cytomegalovirus) activity of compounds 1¡V6 were evaluated. Metabolites 1¡V6 displayed cytotoxicity against P-388 cell line with ED50 values of 0.93, 1.05, 1.20, 1.74, 1.19, 1.19 £gg/mL. However, none of them exhibited inhibitory activity against HCMV (human cytomegalovirus).

In the course of studying on secondary metabolites from marine organisms, we have investigated the chemical constituents of the soft coral Sarcophyton ehrenbergi collected at San-Hsien-Tai, Taitong County, Taiwan. Chromatographic separation of the organic extracts has led to the isolation of nine new cembrane diterpenes 1¡V9, and a initial natural separation of known cembrane diterpene 10. The chemical structures of pure compounds were determined by spectral (NMR, MS, UV and IR) and physical data, as well as comparison with the spectroscopic data of related chemicals in literature. Moreover, the metabolites 1¡V10 were evaluated in vitro for their cytotoxicity against of A-549 (human lung epithelial carcinoma), HT-29 (human colon adenocarcinoma), and P-388 (mouse lymphocytic leukemia) cells, as well as anti-HCMV activity. Compounds 3, 6, 9, and 10 were shown to exhibit significant cytotoxicity activities against P-388 with ED50 values of 2.7, 3.6, 2.0, and 3.0 £gg/mL, respectively. Compound 1, 2, 3, and 7 exhibited inhibitory activity against anti-HCMV, with EC50 values of 60.0, 46.0, 5.0, and 45.0 £gg/mL.

Soft corals of the genus Briareum (Briareidae) have been well known as a rich source for marine natural products with novel structural features. Briarane-related natural products attracted the attentions of researchers because of the structural complexity and interesting biological activity associated with numerous compounds of this type. Previous studies on the secondary metabolites of wild-type and cultured Formosan octocoral Briareum excavatum were collected around the sea area of Kenting. In the thesis of our studies on secondary metabolites from marine organisms, the acetone-soluble of the Formosan octocoral B. excavatum collected at Orchid Island has led to the isolation of eleven briarane-type diterpenoids (1−11), compounds 3, 4, and 6−10 are new compounds. The structures of these compounds were determined on the basis of their spectroscopic analysis (1H NMR, 13C NMR, 1H−1H COSY, HSQC, HMBC, NOESY, IR and mass spectra) and physical data by comparison of the physical and spectral data with those of the related literatures. The antiviral activity against HCMV (human cytomegalovirus) cells of these secondary metabolites was evaluated. Metabolite 8 exhibited significant activity against HCMV cells and compound 11 showed anti-inflammatory activity.−