The Chemical Constituents Of Bryozoan Bugula Neritina L. And Junceella Fragilis From South China Sea

During the course of our search for biologically active constituents in marine invertebrates from South China Sea, the chemical constituents of Bugula neritina L. and the coral Junceella fragilis, collected from the South China Sea, were investigate. The alcohol extracts of Bugula neritina L. and Junceella fragilis were chromatographed and purified by silica gel column, Sephadex LH-20 column, RP-18 column and preparative thin layer chromatography to obtain 76 compounds together. The structures of the 64 isolated compounds in them were identified by spectroscopic analysis, including UV, IR, ESI-MS, 1H-NMR,13C-NMR,1H-1H COSY, HMBC, HSQC, NOESY, X-ray, and comparison with those of literatures,33 Compounds were isolated from Bugula neritina L., and 28 compounds in them were structurally identified:6 macrolides (bryostatins 4,5,6,8,10,14),17 sterols,3 alkaloids, and 2 ceramides; 6 macrolides exhibited antineoplastic activities.9 Compounds were isolated from B. neritina L. for the first time.43 Compounds were isolated from Junceella fragilis, and 38 compounds were structurally identified:27 briarane diterpenoids including 12 new compounds,5 sterols, and 6 others compounds. The relatively configuration of the new briarane diterpenoid PE8-23-A compound was identified by X-ray analysis.19 Compounds were also the first reported about the chemical constituents of Junceella fragilis.The results of toxicity tests against brine shrimp larvae showed that the petroleum ether and ethyl acetate fraction of alcohol extract of B. neritina L. were the active fractions, especially the ethyl acetate fraction. The brine shrimp lethality test, predictive of cytotoxicity and pesticidal activity, was used for bioactivity-driven isolation of Bugula neritina L.The antifouling effects of single constituents of Junceella fragilis were studied. The results showed that some of briarane diterpenoids (A5, A7, A10, A13, A15, A16, N9, Y5, Y6) exhibited antifouling activity at the concentration of 25 ppm, A5, A13 compounds exhibited the stronger antifouling activity; A5, A13, A15 compounds exhibited weak antifouling activity at the concentration of 5 ppm.