Chemical Constituents Of Soft Coral Scleronephthya Sp.and Lemnalia Sp.from South China Sea

The geographic diverse of China sea area inhabit abundant marine organisms.Natural products,due to their novelty and diversity,are the rich sources for lead compounds discovery.Among 500 kinds of current drugs,more than 40 percent of marketed medicines are derived from natural products(or natural products derivatives).Marine organisms are proved to be intact and resourceful for development of natural medicines.Marine organisms live in special ecological environments and possess high pressure,high salinity,low temperature,insufficient light and lack of oxygen.In order to live better,they usually produce metabolize compounds with unique structures and significant bioactivities.Since 1960,a lot of structurally novel and bioactive metabolities,including sterols,sesquiterpenes,diterpenes,glucoside,ceramides,alkaloid,and long chain fatty acids have been isolated from soft coral.Part of the metabolities exhibited potential bioactivities such as antiviral,anti-inflammatory,antibiosis,antitumor,immunosuppression and cytotoxicity activities.In our ongoing program to search for natural products with unique structural features and pronounced biological activities,we have systematically investigated the characteristic metabolites of soft coral Scleronephthya sp.and Lemnalia sp.collected from South China Sea.Compounds were guided by DAD-HPLC and 1H-NMR,obtained by normal phase silica gel,reverse phase ODS and high performance liquid chromatography.Their structures were determined on the basis of 2D NMR(HSQC,HMBC,COSY),MS,UV,IR,specific rotation,CD,which designed to provide the foundation for new drug research and development.By using modern chromatographic method and spectroscopy technology,twelve compounds were isolated from the EtOAc extract of Scleronephthya sp.and Lemnalia sp.Their structures were identified as(S)-13-(2-hydroxy-3,4-dimethyl-5-oxo-2,5-dihydrofuran-2-yl)tridecanoic acid(1),(S)-11-(2-hydroxy-3,4-dimethyl-5-oxo-2,5-dihydrofuran-2-yl)undecanoic acid(2),hydroxydihydrobovolide(3),1,3-dimethylxanthine(4),pregna-20-en-3-one(5),pregna-1,4,20-trien-3-one(6),3?-hydroxy-pregna-20-ene(7),3?-hydroxy-pregna-5,20-diene(8),20-hydroxy-pregna-1,4-dien-3-one(9),20-hydroxy-pregna-l-en-3-one(10),17?-hydroxy-androst-1-en-3-one(11),lemnabourside(12).Compounds 1 and 2 are new compounds.Chemical constituents from the EtOAc extract of soft coral Scleronephthya sp.are mainly pregnane steroids and butenolides are obtained from the genus Scleronephthya for the first time.