Studies in marine natural products
The marine environment continues to be a prolific source of structurally diverse and biologically active natural products. Over the past few decades both macroand micro-organisms have been extensively studied for such compounds. Annual reviews are dominated by novel compounds isolated from marine sp...
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| Format: | Other/Unknown Material |
| Language: | English |
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University of Canterbury
2005
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| Online Access: | http://hdl.handle.net/10092/12757 https://doi.org/10.26021/6426 |
| Summary: | The marine environment continues to be a prolific source of structurally diverse and biologically active natural products. Over the past few decades both macroand micro-organisms have been extensively studied for such compounds. Annual reviews are dominated by novel compounds isolated from marine sponges, even though investigations have more recently been focused on micro-organisms. After decades of research into the development of marine natural products as potential pharmaceuticals, many marine compounds now feature prominently in current pre-clinical and clinical trials. This thesis represents a continuation of work in the area of isolation and structural elucidation of novel and/or biologically active natural products from both marine macro- and micro-organisms. The four novel Cāā polyacetylenic compounds 2.23, 2.24, 2.25 and 2.26 were isolated as the major components of the cytotoxic extract of the New Zealand marine sponge Rhabderemia stelletta, using bioassay-guided separation techniques. However, these structures were not unambiguously assigned due to the low resolution of the NMR signals associated with the long-chain alkyl protons and carbons. Elucidation was also hindered by compound degradation during structural analysis. The partial structures were identified via mass spectrometry and NMR spectroscopy and comparison of structural data for similar compounds reported in the literature. The novel pteridines 3.13 and 3.15 were isolated as the major and minor components, respectively, from the cytotoxic organic extract of an as yet unidentified Antarctic marine sponge 02WM01-33. Identification was achieved using mass spectrometry and NMR spectroscopy, and comparison of these data to those published in the literature for similar structures. Although pteridines are distributed widely throughout nature, 3.13 and 3.15 represent a chemically interesting group of compounds as they possess a mono-oxygenated methyl side chain, which has not been previously reported among any of the naturally occurring ... |
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