The Secondery Metabolites And Their Bioactivies Of Sinularia Sp. And Verrucella Umbraculum

Corals are one of common marine invertebrates which lack of efficient physicalprotection mechanism with soft bodies and attached growth. They are easily attackedby other organisms in marine environment. Wheras they survive mainly relying ontheir chemical defensive system with a series of secondary metabolites. Viours ofbioactive secondary metabolites such as antitumor, antifouling, antibacterial, antiviruscompounds have been found from the corals, which will be a good supply for thedevelopment of marine drugs and the research on the lead compounds.In this paper, the bioactive secondary metabolites of soft coral Sinularia sp.(GX-WZ-2008002-4) collected from the South China Sea and gorgonian Verrucellaumbraculum (GX-WZ-2010004-21and YWQD-2006-4) which was collected fromdifferent locations in the South China Sea have been investigated. The compoundswere isolated by using of chromatography methods (silica gel, Sephadex LH-20, ODSand HPLC). And their structures were elucidated by comprehensive spectroscopy (1DNMR,2D NMR, Optical rotation, MS, UV, IR). Twenty-eight compounds wereidentified, and5of them were new compounds.Twelve compounds were isolated from Sinularia sp.(GX-WZ-2008002-4),including three uncommon sterols with C-25-OH functions (1–3); fourpolyoxygenated sterols (4–7); two lipids (8–9) and three ceramides (10–12). Thisstudy provided a series of polyoxygenated sterols, especially the discovery of newcompounds1–3, adding to an extremely diverse and complex array of soft coralsterols.Eight compounds were identified from Verrucella umbraculum(GX-WZ-2010004-21) collected from Weizhou island coral reef in the South China Sea. They were four uncommon C-27-acetoxy sterols (13–16); two common sterols(17–18) and two ceramides (19–20). Compounds13,14,15,16,17,19and20wereisolated from Verrucella umbraculum for the first time, and compounds13,14werenew compounds.Eight compounds were isolated from Verrucella umbraculum (YWQD-2006-4)collected from Meishan coral reef of Sanya sea area in the South China Sea. Theywere two uncommon polyoxygenated sterols displaying a rare24-ketal function(21–22); one reticulatic acid (23); four common sterols (24–27) and one briaranediterpene (28). Compounds25,27,28were isolated from Verrucella umbraculum forthe first time.Bioassay screening modles were used to evaluate the bioactivities of thesecompounds, including antibacterial, antitumor, antifouling as well as lethality to brineshrimp activities. Polyoxygenated sterol5from Sinularia sp.(GX-WZ-2008002-4)exhibited cytotoxic activity against human tumor cell line K562with an IC50value of3.18μM. In addition, compound5was also found to be toxic to brine shrimp Artemiasalina with a LC50value of0.96μM. Besides, uncommon polyoxygenated sterol21from V. umbraculum (GX-WZ-2010004-21) also exhibited lethality to brine shrimpArtemia salina.The study on the bioactive secondary metabolites from Sinularia sp.(GX-WZ-2008002-4) and V. umbraculum (GX-WZ-2010004-21and YWQD-4,respectively.) revealed that sterols were the common secondary metabolites of thecorals; however, sterols display different structures from different species. Morever,different collected time and waters of the same species also led to the differentstructure metabolites. A number of bioactive compounds could provide basic data forexploring secondary metabolites of the corals in chemical ecology effects and theirapplication.