Studies On The Chemical Constitutions And Bioactivities Of Two Soft Corals From The South China Sea

The dissertation deals with chemical constituents and bioactivities of two soft corals Sinularia sp.and Sarcophyton mililatensis collected from the South China Sea.We have successfully investigated 2 marine invertebrates,35 compounds were isolated and purified by TLC,silica gel,Sephadex LH-20 column chromatograpy and semi-preparative HPLC.Among these compound,10 were identified to be new compounds.The new compounds can be divided into 8 cembrane-type diterpenoids and 2 steroids.Their structures were characterized by analysis of ¹H,¹³C NMR?2D NMR?HR-MS?UV?IR?[?]?ECD data and comparison with the data reported in literature.The absolute configuration of some compounds were established by the modified Mosher's method,Octant Rule and TDDFT-ECD calculation.In in vitro bioassays,some compounds showed good biological activity.This enriched the chemical diversity of marine invertebrates from the South China Sea.Meanwhile,the SAR?Structure-activity relationship?was concluded,which provide the basis for our further development and utilization of marine biological resources of the South China Sea.During studying on chemical constituent and bioactivities of the Chinese soft coral Sinularia sp.,we obtained 14 sterols from the acetone extract of soft coral.Two of them are new?2-13*and 2-14*?,twelve of them identified as known compounds.Notably,2-13*possesses an uncommon dihydrofuran group.The absolute configuration of 2-14*was determined by applying the modified Mosher's method.In bioassay,compounds 2-13*and 2-14*showed significant cytotoxicity against the HL-60 tumor cell line with IC₅₀ values of 1.79 and 4.03?M,respectively.During studying on chemical constituent and bioactivities of the Chinese soft coral Sarcophyton mililatensis,we obtained 21 compounds from the acetone extract of soft coral.Eight of them are new?3-4*,3-9*,3-10*,3-11*,3-16*³-19*?,thirteen of them identified as known compounds.The absolute configuration of 3-9*was established by the modified Mosher's method,while the absolute configurations of 3-16*and 3-17*were assigned by ECD spectroscopy and that of 3-4*was established by TDDFTECD calculation.In bioassay,the known compound 3-7displayed significant cytotoxicity against the human cancer cell lines HL-60 and A-549 with IC₅₀ values of 0.78 and 1.26?M,respectively.3-7 and 3-16*also showed moderate inhibitory effects on the TNF?-induced NF-?B?a therapeutical target in cancer?activation,showing IC₅₀ values of 22.52 and 35.23?M,respectively.