Studies On Bioactive Constituents Of The Gorgonian Melithaea Sp. And The Soft Coral Lobophytum Sp.

Coral found throughout the oceans of the world, especially in the tropics and subtropics. There are 719 species in China, Until 1960s, a lot of structurally novel and bioactive secondary metabolities, including diterpenes, sterols, alkaloid and lipid, have been isolated from Coral. The constituents exhibited potential bioactivities such as antiflammation, anti-bacterial, antioxidization, antitumor, antituberculosis and generating immunity.Isolation and structure determination:The MeOH/CH2Cl2 extracts of the gorgonian Melithaea sp. and the soft coral Lobophytum sp. were chromatographed on silica gel, TLC and Sephadex LH-20, and semi-preparative HPLC, respectively, then 11 compounds were isolated and purified from the gorgonian Melithaea sp., and 22 compounds were isolated from the soft coral Lobophyon sp. Coral. All these compounds were identified on the basis of spectral methods (1D-NMR,2D-NMR, MS, IR, etc.) and their physicochemical properties.Structures of the compounds isolated from the gorgonian Melithaea sp. were determined as:1,2-benzenedicarboxylic acid bis(2-ethylhexyl)ester(M-l), diisobutylphthalate(M-2),Dibutyl-O-phthalate(M-3),brassicasterol(M-4),Cholest-5,22-dien-β-ol(M-5),24-methylene-holesterol(M-6),Cholesta-5,23E)-dien-3β-ol(M-7),chol esterol(M-8),Guaianediol(M-9),Hydroxydihydrobovolide(M-10),5-hydroxy-3,4-dime thy-5-propyl-2(5H)-furanone(M-11), respectively.And the structures of compounds from soft coral Lobophytum sp. were identified as:gorgosterol(L-1),24-methylenecholesterol(L-2), brassicasterol(L-3), cholesterol(L-4). Lobophytolide B(L-5),3-dehydroxyl-20-acetylpresinularolide B(L-6), Hydroxydihydrobovlide(L-7), Lobophytolide G (L-8) Lobophytolide F(L-9), Durumolide B(L-10), Lobophytolide H (L-11), Lobophytolide I (L-12), Lobolide(L-13), Lobophytolide E(L-14), Lobophilide B(L-15), Lobophytolide D (L-16), Sinularolide D(L-17), (7E,11E)-18-Acetoxy-3,4-epoxy-13-hydroxy-7, 11,15(17)cembratrien-16,14-olide(L-18), Durumolide C(L-19), Lobophytolide J (L-20), Sinularolide C (L-21), Lobophytolide K (L-22)。Biological activities:Compound M-9, M-10 and M-11, isolated from the gorgonian Melithaea sp., and 17 compounds isolated from the Lobophytum sp.were evaluated for their cytotoxicities against P388, Hela or K562 cancer cell lines by MTT method. The results indicated that M-9-M-10 have weak anti-tumor activities. And compound L-8, L-18, L-19 and L-20 isolated from Lobophytum sp. showed remarkable anti-tumor activities.Compound M-9-M-11, isolated from the gorgonian Melithaea sp., and 17 compounds isolated from the Lobophytum sp.were evaluated for their activities against c-Met by ELISA method. The result is that all of the compounds have no activities against c-Met.