Isolation and structure elucidation of natural products from marine sponges and an invertebrate were performed. The marine sponges and invertebrate were obtained from three locations including South East Queensland, in Australia, Pontianak in West Kalimantan, and Tulamben, in Bali, Indonesia. The natural products were purified using chromatographic techniques, the structures were elucidated by means of extensive 1D and 2D NMR spectroscopy and some were confirmed by X-ray crystallography. Five known compounds and potentially a new metabolite were identified from three different sponges and a species of nudibranch obtained in Mooloolaba, South East Queensland in Australia. Furospinosulin-1 (4.5), a linear sesterterpenoid, was identified from a sponge coded 20-1-07-1-7 while imidazole alkaloids, preclathridine A (4.9) and clathridine (4.10), were characterized from sponge 22-4-07-2-1. The ethyl acetate extract of sponge 14-7-07-1-1 yielded a polyacetylene fulvinol-like compound (4.15) and potentially a new metabolite compound 5 (4.21). Additionally, a specimen of Chromodoris kuiteri furnished a cyclic macrolide latrunculin A (4.27). There were six secondary metabolites identified from Aaptos aaptos, two of which to the best of our knowledge were new compounds. Aaptamine (5.1), a chemotaxonomic marker of the sponge A. aaptos, 9-demethylaaptamine (5.3) and a biosynthetically unrelated compound (-)-jaspamide (5.31) were found as major constituents of the dichloromethane extract of the sponge. On the other hand, a known indole-3-carbaldehyde (5.10), and the two new natural products methyl 3-(8,9-dimethoxy-4H-benzo[de][1,6]naphthyridin-4-yl)propanoate (5.11) and 8,9-dimethoxy-4H-benzo[de][1,6]naphthyridine-5,6-dione (5.30) were isolated as minor components. During a two-month fieldwork trip to Tulamben, Bali, six different sponges were obtained. Investigation of a blue colored sponge Petrosia sp. afforded two isoquinolinequinone metabolites, namely mimosamycin (5.35) and O-demethylrenierone (5.36). A new 3-alkylpiperidine metabolite, tetradehydrohaliclonacyclamine A (6.28), was isolated from a sponge Halichondria sp. The structure and relative stereochemistry of 6.28 were determined from analysis of 2D NMR data and interpretation of coupling constants. Suitable crystals that were grown from hexane: ethyl acetate (1:3) allowed the determination of the absolute configuration of 6.28 and it was established to be 2S, 3S, 7S, and 9S on the basis of X-ray crystallographic data. The isolated compound (6.28) appeared to be as a single enantiomer according to chiral HPLC. The parent compounds, haliclonacyclamine A (6.19) and B (6.20), were re-isolated from a sample (coded BK-Hal-12-AIK) obtained from a previous project on Haliclona in our group. Their absolute configurations were determined for the first time by X-ray crystallography and they were established to be 2R, 3R, 7R, and 9R.
| Identifer | oai:union.ndltd.org:ADTP/279125 |
| Creators | I Wayan Mudianta |
| Source Sets | Australiasian Digital Theses Program |
| Detected Language | English |
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