Studies On Chemical Constituents From The Marine Sponge Spongia Sp.and Their Biological Activities

The marine sponge of genus Spongia belongs to the family Spongiidae(Demospongiae,Dictyoceratida).Studies have been found that the sponge contains a variety of secondary metabolites,including terpenoids,steroids,ceramides and macrolides.These novel compounds exhibit a variety of biological activities,such as cytotoxicity,antiviral,anti-inflammatory and immunosuppressive activities,which have attracted the extensive attention of the researchers.In searching for bioactive constitutes,we had systematically investigated the chemical constitutes of the 95%ethanol extraction of Spongia sp.,which was collected from Xuwen,Zhanjiang in Guangdong Province.50 Compounds had been isolated from the extraction of this sponge.By the methods of spectroscopic techniques as well as physical and chemical properties,the structures of these compounds were elucidated as spongiain A(S1),spongiain B(S2),spongiain C(S3),bisnorspongiain A(S4),bisnorspongiain B(S5),bisnorspongiain C(S6),bisnorspongiain D(S7),bisnorspongiain E(S8),bisnorspongiain F(S9),bisnorspongiain G(S10),bisnorspongiain H(S11),norspongiain A(S12),norspongiain B(S13),norspongiain C(S14),norspongiain D(S15),norspongiain E(S16),norspongiain F(S17),spongiain D(S18),spongiain E(S19),spongiain F(S20),spongiain G(S21),(+)-spongiterpene[(+)-S22],(-)-spongiterpene[(-)-S22)],1H-indole-3-carbaldehyde(S23),1H-indole-3-carboxylic acid(S24),1H-indole-3-carboxylic acid acetate(S25),indazole(S26),dehydrololiolide(S27),loliolide(S28),(+)-dehydrovomifoliol(S29),?-hydroxy-5?,6?-epoxy-7-megastimen-9-one(S30),?-cholesterol(S31),?-sitosterol(S32),3?-hydroxycholest-5-en-7-one(S33),(S)-5-hydroxy-3,4-dimethyl-5-pentylfuran-2(5H)-one(S34),(S)-5-hydro-3,4-dimethyl-5-oxo-2-furantridecanoic acid actetate(S35),4-hydroxybenzaldehyde(S36),benzoic acid(S37),phenylacetic acid(S38),4-methoxyphenylacetic acid(S39),hypoxanthine(S40),adenine(S41),6-methoxy-7-methyl-8-oxoguanine(S42),2?-deoxyuridine(S43),uridine(S44),2?-O-methyluridine(S45),2?-deoxythymidine(S46),?-adenosine(S47),2?-deoxyadenosine(S48),5?-deoxy-5?-methylamino-adenosine(S49)and inosine(S50).Among them,S1-S22 were the new ones.S1-S3 were the first examples of spongian diterpenes bearing a pentacyclic skeleton composed of a fused 5/5/6/6/5 ring system through ring A rearrangement.S4-S11 were the first examples of 18-norspongian diterpenes with ring A-opened.(+)-S22 and(-)-S22 were a pair of new valerane-type sesquiterpene enantiomers,which were first discovered from sponge.(+)-S22 and(-)-S22 were obtained by chiral HPLC.The plausible biogenetic pathway of these new spongian diterpenes were also discussed.The biogenetic pathway had undergone many reactions such as oxidation,decarboxylation and condensation on the basic skeleton of spongian diterpenes.The precursor of 19-norspongian diterpene was the spongian diterpene with C₂₀ skeleton and the precursor of 18-norspongian diterpene was the 19-norspongian diterpene,which confirmed that 18-norspongian diterpene was the main constituents of this sponge.The anti-fouling,cytotoxic,antibacterial and anti-viral activities of these compounds were tested.In the anti-fouling activity test,the adhesion rates of S1,S2,S4,S6 and S16 were less than10%after 4 h and the adhesion rates of S14 and S20 were less than 50%after 4 h.In the cytotoxicity test,S16 showed moderate cytotoxicity to PBL-2H3 and PC3 cell lines with IC₅₀27.2and 24.8?M,respectively.However,S2 and S3 promoted proliferation of RBL-2H3 cells in a dose-dependent between 10-80?M concentrations,which suggested that these compounds could be used to conduct related activity tests and mechanism studies in promoting angiogenesis,tissue repair and neuroprotection in the subsequent studies.