Study On Chemical Constituents And Bioactivities Of The Sponge Agelas Aff. Nemoechinata

The Sponge Agelas aff. Nemoechinata is a sessile animal of the Phylum Porigera,Subclass Demospongiae, Class Agelasida, familyAgelasidae, widely distributed in themajor seas of the world. The chemical constituents research of the species began inthe1980s, however, there are19species of the genus Agelas have been studied, and alarge number of pyrrole alkaloids, terpenoids and a few polyketides have beendiscovered, half of the compounds showed good antimicrobial activity and anti-tumor activity,and a small number of the compounds exhibited anti-pollution activity, which showedrich chemical diversity and potential research value of the marine natural products.The South China Sea contains a large number of marine organisms, notably sponges,in our ongoing program to search for natural products with pronounced biologicalactivities and unique structural features, we have performed a systematic investigationon the chemical constituents and biological activities of the sponge Agelas aff.Nemoechinata collected from the Paracel Islands of the south of China, in November,2009.Isolation and structure determination: Monitoring by bioassay-guidedisolation, the MeOH extract of the sponge Agelas aff. Nemoechinata waschromatographed on Sephadex LH-20, silica gel, TLC and semi-preparative HPLC,respectively. Then twenty-five compounds were isolated and purified from the spongeAgelas aff. Nemoechinata. Thirty-five compounds were identified on the basis ofspectral methods (IR, MS, NMR, CD and caculated ECD et al..) and theirphysicochemical properties.Among them, there were five new compounds and onecompound with novel skeleton (as new compounds). The compounds: NemoechineA(*+1)å'Œ(*-1), Nemoechine B(*+2)å'Œ(*-2), Nemoechine C(*+3)å'Œ(*-3),Nemoechine D(*4), Nemoechine E(*5), agelasidine D(6), axistatin2(7), axistatin1(8),[3-ethyl-5-(2-ethyl-3-hexenyl)-5-methyl-2(5H)-furanylidene]-methyl ester(9), 2-[3,5-diethyl-5-(2-ethyl-3-hexen-1-yl)-2(5H)-furanylidene]-acetic acid methylester(10),[3-ethyl-5-(2-ethylhexyl)-5-methyl-2(5H)-furanylidene]-methyl ester(11),2-[3,5-diethyl-5-(2-ethylhexyl)-2(5H)-furanylidene]-acetic acid methylester(12),2-[3,5-diethyl-5-(2-methylhexyl)-2(5H)-furanylidene]-methyl ester(13),Methy-N-[(2-pyrrolyl) carbonyl] glycinate(14), N-(3-hydroxypropyl)-2-carboxamidePyrrole(15), N-(2-aminoethyl)-2-carboxamide Pyrrole(16),1H-indole-3-carbaldehyde(17),6-hydroxy-4,4,7a-trimethyl-5,6,7,7a-tetrahydrobenzofuran-2(4H)-one (18),2-pyrrole-carboxamide(19),5-aminopentanoic acid (20), Thymine (21), Uracil (22),1-H-pyridone (23), deoxyuridine (24),deoxythymidine (25).Biological activities: Most pure compounds were evaluated for theircytotoxicities against HL-60(human leukemia cells), HeLa (human cervicalcarcinoma cells), P388(murine leukemia cell), and K562(chronic myelogenousleukemia cell lines of the original) cancer cell lines by SRB or the MTT method withdoxorubicin for the positive control. The results show that the new compound4showed strong cytotoxic activity against HL-60cell lines with IC50values of9.95compound6showed strong cytotoxic activity against Hela cell lines with IC50valuesof8.89and against HL-60cell lines with IC50values of0.88Compound10showed strong cytotoxic activity against HL-60cell lines with IC50values of3.64Research significance: The systematic investigation on the chemicalconstituents and biological activities of the sponge from The South China Sea showedthat our distant sea sponges have rich chemical diversity, whitch is an importantresource to find marine bioactive substances.