Studies On The Chemical Constituents Of The Sponge Spongia Officinalis

ObjectiveTo investigate the chemical constituents of spongia officinalis collected from Weizhou Island,Guangxi Autonomous Region,China South Sea.MethodsThe frozen sponge specimens were cut into pieces and exhaustively extracted with acetone at room temperature.The organic extract was evaporated to give a residue,which was successively partitioned between Et₂O and H₂O,n-BuOH and H₂O.The Et₂O soluble portion was concentrated under reduced pressure to give a black residue,which was subjected to silica gel column chromatography eluted with Petroleum ether and Et₂O.The n-BuOH soluble portion was concentrated under reduced pressure to give a yellow residue,which was subjected to silica gel column chromatography eluted with CH₂Cl₂/MeOH.Each fraction was purified by silica gel,follow by semi-preparative and chiral HPLC,some pure compounds were obtained.Those compounds were identified by NMR,MS,ECD calculation and biosynthesis to determine their planar construction and stereostructure.Results15 compounds were isolated from the sponge,5 compounds were novel compounds,10 compounds were known compounds.?+?-sponalisolide A?1a?,?-?-sponalisolide A?1b?,?+?-sponalisolide B?2a?,?-?-sponalisolide B?2b?,which were synthesized by eight step.3-nor-spongiolide A?3?,spongiolide A?4?,spongiolide B?5?,spongia-13?16?,14-diene?6?,18-nor-3,17-dihydroxyspongia-3,13?16?,14-trien-2-one?7?,spongiatriol?8?,isospongiatriol?9?,epispongiatriol?10?,17,19-dihydroxyspongia-13?16?,14-dien-2,3-dione?11?,?-?-untenospongin B?12?,kurospongin?13?,C21 fasciculatin acid?14?,fasciculatin?15??ConclusionsThis was the first investigation on the chemical components and bioactivities of spongia officinalis from China South Sea,leading to the discovery of 15 compounds,1-5 were novel compounds.The absolute configuration of 1 and 2 was determined by biosynthesis,while the absolute configuration of 3-5 was determined by ECD calculation.The investigation on the chemical constituents of the sponge showed the China South Sea have rich chemical diversity,which is good for further bioactivities test to find active compounds.