Study On Chemical Constituents And Bioactivities Of The Marine Sponge Aaptos Aaptos From Xisha Islands

The sponge Aaptos aaptos belongs to class Demospongiae, order Hadromerida and family Suberitida. There are series of reports on this sponge from many research groups all over the world. The results show that marine sponges of genus aaptos are rich in marine alkaloids, which contain a benzo[de][1,6]naphthyridine framework and varied biological activities, including their antioxidant, enzymatic inhibition, antiviral, antimicrobial, antifungal, antiparasitic, cytotoxic, antifouling, and antidepressant activities. We ongoing research on the isolation of new bioactive metabolites from marine sponges collected off the Xisha Islands in the South China Sea.The sponge Aaptos aaptos collected in may, 2013. In our study 17 compounds(1-17) were isolated and purified from the CH2Cl2 fraction of the methanol extract, by using solvent extraction and chromatographic methods including VLC, LPLC, MPLC, HPLC on silica gel, ODS C-18 and Sephadex LH-20. These structures were elucidated by IR, UV, 1H-NMR, 13C-NMR, 1H-1H COSY, HMQC(HSQC), HMBC, NOESY(ROESY) and HRESIMS as: 9-methoxy-2-methyl-1,2a,5-triaza-cyclopenta [cd]phenalene(1), 3-[2-(4-Hydroxyphenyl)-ethylamino]-8-methoxy-benzo[de][1,6] naphthy ridin-9-one(2), 3-(phenethylamino)demethyl(oxy)aaptamine(3), 2-isopropyl-10-methoxy-1,3a,6- triazapyren-3-one(4), demethyl(oxy)aaptamine(5), 8,9,9-Tri methoxy-9H-Benzo[de] [1,6]naphthaayridin(6), aaptamine(7), 9-methoxy-1,2a,5-triazacyclopenta[cd]phenalene(8), 3-(methylamino)demethyl(oxy) aaptamine(9), 3-(isopentylamino)-demethyl(oxy)aaptamine(10), isoaaptamine(11), 11-methoxy-3H-[1,6]naphthyridino[6,5,4-def]quinoxalin-3-one(12), 3-aminode methyl(oxy)aaptamine(13), 2,3-dihydro-2,3-dioxoaaptamine(14), dihydroaaptamine(15), dihydrodemethylaaptamine(16), demethylaaptamine(17).Some compounds were evaluated for activity screening of cytotoxicity compound 1 exhibited cytotoxicity against cancer cell lines He La and K562 with IC50 value 12.32 and 10.63 μM. Compound 3 exhibited cytotoxicity against cancer cell lines He La and K562 with IC50 value 7.35 and 1.70 μM. Compound 5 exhibited cytotoxicity against cancer cell lines He La, K562, MCF-7 and U937 with IC50 value 6.90, 0.90, 4.62, 2.76 μM. Compound 7 exhibited cytotoxicity against cancer cell lines K562, MCF-7 and U937 with IC50 value 3.84, 3.13, 1.62 μM. Compound 9 exhibited cytotoxicity against cancer cell lines A549 and K562 with IC50 value 4.39 and 7.71 μM.The studies focused on the chemical constituents of Aaptos aaptos and their bioacticities. Bioassay-guided fractionation led to the isolation of 17 compounds. The results of bioactivity text indicate that some compounds exhibited potential cytotoxicity, which could provide new leads for the development of new anticancer drugs, and also play an important role for the development and medicinal usage of the marine biological resources.