GC-MS Analysis of Some Bioactive Constituents from the Marine Sponge Spongosorites halichondriodes

Abstract

Sponges have proved to be a rich source of sterols with unusual structural features 1, 2. They are also a rich source of structurally unusual and interesting fatty acids and steryl esters. To analyze and extract phylogenetic information from chemical characters, the 3-hydroxysterol composition of Halichondria lutea, H. magniconulosa, Topsentia ophiraphidites, and Petromica ciocalyptoides (family Halichondriidae) were studied. Three out of four Halichondriidae species were related by a unique sterol property. The diversity of sterols found in the studied species of Halichondrida confirms the usual pattern in Porifera 3. A close relationship between Topsentia and Petromica has already been drawn from morphology 4 and from similarity in secondary metabolite composition 5. In contrast, the two studied species of Halichondria came out separately in the analysis, not sharing a sterol synapomorphy, further evidencing the fact that this genus has been mainly defined by primitive characters 4, 6 and that it is polyphyletic 7. It is of special interest that, although some sponge species provide the greatest structural diversity of membrane sterols in comparison with any other animals, many of the studied sponges have sterol compositions resembling those of animals belonging to other taxa. In another study, D. australiensis contained 7 -, 5 -, 5,7 -, 5,7,9 (11)-sterols, and cholest-7-ene-3-ol was shown to be a main sterol. The free sterols from A. mauritiana proved to be stanols and 7 -series compounds. Haliclona sp. contained 5 -sterols with cholesterol as a main constituent. C. major and D. aceratus contained 5 -sterols, and clionasterol was a main sterol. T. labirintica was shown to contain 3-hydroxymethyl-A-nor-sterols. 8. The Caribbean sponge Neofibularia nolitangere showed comparable amounts of 24-methylene-4-methyl-5-cholest-8-ene-3-ol, which is very unusual among sponge sterols, and lesser quantities of two new polyoxygenated sterols, (24S)-24-ethyl-5-cholest-8-ene-5,6,7-triol and (24S)-24-ethyl-5-cholest-8(14)-ene-5,6,7triol 9. In our search for active compounds in Spongosorites halichondriodes, a marine sponge of class Demospongiae and family Halichondriidae, we have found that polyhydroxy steryl esters and cholesterol are predominant in this species. Spongosorites sp. is in almost all instances found in association with Vermetid molluscs and possesses potent bioactive compounds. Interestingly, it has also been observed that organisms that are conspicuously colored and live in habitats with limited or no ambient light often possess interesting secondary metabolites (Dercitus sp. and Spongosorites sp.) Seven monoindole derivatives were isolated from the MeOH extract of the marine sponge Spongosorites sp. by bioactivity-guided fractionation 10. Also, four bis (indole) alkaloids of the topsentin class, including two new brominated compounds, have been isolated from the sponge Spongosorites genitrix collected from Jaeju Island, Korea 11. These compounds also exhibited moderate cytotoxicity against cancer cell lines at concentrations between 1.1 and > 20 g/mL 12. Spongosorites halichondriodes has been studied and investigated for its antibacterial and antifungal activity. It has shown prominent antimicrobial activity in all the extracts along with cytotoxic activity in ethyl acetate extract. In the current work, the data collected from the GC-MS of the butanol extract was analyzed, and spectral matches were searched by comparing the parent ion fragmentation pattern m/z with the Mass Bank Database, Japan using Quick peak Search. The separation chromatogram of the crude extract of butanol and ethyl acetate showed the presence of similar peaks; butanol was selected for MS because of major peaks. Identification of Compounds by GC-MS. The fatty acid composition of phospholipids from marine sponges of the Colombian Caribbean Sea of the order Halichondrida (Halichondria magniconulosa, Halichondria lutea, Petromica ciocalyptoides, Axinyssa ambrosia, Didiscus oxeata, and Dragmaxia undata) has already been studied. Structure elucidation was accomplished by means of gas chromatography retention parameters and GC-MS of eight new fatty acids and their methyl esters and N-acylpyrrolidide derivatives (i.e., 5-methyl-6-octadecenoic, 16-methyl-11-heptadecenoic, 8-methyl-4-tetracosenoic,