Study On The Bioactive Constituents Of Three Marine Sponges From Xisha Islands

Because of the lack of physical protection,the sponges formed complex chemical defense system in the course of a long-term evolution process,such as the compounds with antitumor,antiviral,antibacterial,anti-inflammatory and immunoregulatory biological activities.Marine sponges are the focus in the research of marine natural products.Chemical investigation on Niphates sp.,Petrosia sp.,and Plakortis simplex,which collected in Xisha islands,by various chromatographic methods led to the isolation and structure determination of 50 compounds.Among these compounds,21 of them were new compounds.Most of the compounds were evaluated for cytotoxic and antibacterial activities.9 compounds were isolated from the methanol extraction of the marine sponge Niphates sp.by using various of chromatography methods.They were identified by NMR and MS spectrums and chemical reactions,including six polyacetylenic alcohols,one alkaloid,and two nucleic acids,These compounds are identified as follows:pellynols M-O(A1-A3),melyne B(A4),melyne A(A5),pellynol I(A6),Zn-complex of clathridine(A7),2’-deoxythymidine(A8),and 2’-deoxyuridine(A9).Among these compounds,A1-A3 were new,A4-A9 were firstly isolated from the Niphates genus.Compounds Al,A2,A4,and A5 showed potent cytotoxicity against PC9,HepG2,and MCF-7 cancer cells,expecially against the HepG2 cell with IC50 of 2.9-5.9μM,which were similar with that of sorafenib(3.7 μM).Various of chromatography methods were used to study the chemical constituents of the methanol extraction of the marine sponge Petrosia sp.21 compounds were isolated from the CH2Cl2 extract.They were identified by NMR and MS spectrums,including twenty polyacetylenes and one lactone.These compounds are identified as follows:petronols A-R(B1-B18),pellynol I(B19),pellynol N(B20),and hydroxydihydrobovolide(B21).Among these compounds,B1-B11,B13,B16,and B18 were new.Compounds B9-B12 and B16-B19 showed potent cytotoxicity against HepG2,HT29,and A375 cancer cells with IC50 of 1.4-6.4μM,and their structure-activity relationships were discussed.20 compounds were isolated from the n-butanol extract of the marine sponge Niphates sp.by using various of chromatography methods.They were identified by NMR and MS spectrums and modified Mosher method,including nine sesquiterpene phenols,seven alkaloids,and four others.These compounds are identified as follows:plakordiols A-D(C1-C4),(7S,10R)-hydroxycurcudiol(C5),(75,10S)-hydroxycurcudiol(C6),(S)-(+)-curcudiol(C7),(7S*,10S*)-abolene(C8),(7S*,10R*)-abolene(C9),4,5,6-Trimethyl-5,6-dihydro-2H-pyran-2-one(C10),dehydrovomifoliol(C11),loliolide(C12),ethyl dioxindole-3-acetate(C13),dehydrololiolide(C14),1H-indole-3-carboxaldehyde(C15),1H-indole-3-carboxylic acid ethyl ester(C16),2-bromoaldisin(C17),theophyline(C18),caffeine(C19),indazole(C20).Among these compounds,C1-C4 were new.Compounds C1-C14 and C17-C18 didn’t show cytotoxic and antibacterial activities.