||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 1–27, including nineteen new eunicellin–type diterpenoids, simplexins A–S (1–19) from K. simplex, one new steroid 11α,15α-diacetoxy-17β-pregna-4,20- dien-3-one (20) along with one known compound 17β-pregna-4,20-dien-3- one (21) from S. mollis, and six new briarane–type diterpenoids briaexcavatolides Q (22), S–V (23-26) and W (27) from B. excavatum. The structure of these compounds were established by the detailed spectroscopic analysis (IR, MS, 1D、2D 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 1–6, 9, 13–15 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 1–6, 9, 13–15 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.