Chemical Constituents And Their Bioactivities Of One Soft Coral Lobophytum Sp

Coral grows throughout the oceans of the world, especially in the tropics and subtropics. There are719species in China. Until1960s, 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 so on.The soft coral Lobophytum sp. belongs to class Anthozoa, order Alcyonacea, and family Alcyoniidae. There are series of reports about soft coral of the genus Lobophytum. The results show that soft coral of the genus Lobophytum are rich in novel compounds with good biological activities. Up to now, a large number of secondary metabolites have been reported from this genus of soft coral, including diterpenes, sterols, alkaloids, lipids, and other types of chemical components. Many of them exhibited significant biological activities including antiflammation, anti-bacterial, antioxidization, antitumor, antituberculosis and so on. In the course of our continuing search for drug leads from soft corals of the Xisha Island, we studied the chemical constituents and bioactivities of the soft coral Lobophytum sp. from Woody Island of Xisha Island.Isolation and structure determination:The MeOH/CH2Cl2extracts of the soft coral Lobophytum sp. were chromatographed on silica gel, TLC and Sephadex LH-20, and semi-preparative HPLC, respectively, then21compounds were isolated and purified from the soft coral Lobophytum sp. All these compounds were identified on the basis of spectral methods(1D-NMR,2D-NMR, MS, IR, etc.) and their physicochemical properties, the structures of compounds from soft coral Lobophytum sp. were identified as:Sarsolilide B (L-1*),(2S*,11R*,12R*)-isosarcophytoxide C (L-2*), Lobocrasol B (L-3*), sarcophytonin E (L-4*),16-Oxosarcophytonin C (L-5*),(1S*,3S*,4S*,7E,11E)-3,4-epoxy-13-oxo-7,11,15-cembratriene (L-6), Sarcrassin E (L-7),3-dehydroxyl-20-aeetylpresinularolide B (L-8), laevigatol (L-9),(+)-isosarcophine (L-10),(2E,4E,8S,12Z)-1-isopropyl-4,8-dimethyl-7-oxocyclotetradeca-1,3,11-triene-8,12-carbolactone (L-11),(2E,4E,7R,8S,12Z)-1-isopropy -lcyclotetradeca-4,8-dimethyl-7-hydroxy-1,3,11-triene-8,12-carbolactone (L-12), Sarcra-ssin D (L-13), Sarcophytonone (L-14), honulactone A (L-15), Hydroxydihydrobovlide (L-16),1-O-hexadecyl-2,3-dihexedecanoyl glycerol(L-17), Cholest-5,22-dien-β-ol(L-18), Dibutyl-O-phthalate(L-19), diisobutylphthalate(L-20), gorgosterol (L-21),Biological activities:compounds isolated from the Lobophytum sp:were evaluated for their cytotoxicities against B16F10, Hela or HepG2oancer cell lines by MTT method. The results indicated that L-7, L-8, L-9, L-11, L-12, L-17have weak anti-tumor activities. Compound L-6and L-10isolated from Lobophytum sp. showed remarkable anti-tumor activities.