The natural product 2 crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxy-cyclohex-2-enone (COTC) was isolated from the microorganism Streptomyces griseosporeus in 1975. It was shown to exhibit 'cytotoxic and cancerostatic activity'. The simplified synthetic analogue 2-crotonyl-oxymethyl-cyclohex-2-enone (COMC) has been shown to exhibit potent anti tumour activity against murine and human tumours in cell culture. For several years, the Whitehead research group at the University of Manchester have focused on the synthesis of COTC and COMC analogues in an attempt to produce compounds with enhanced cytotoxicity. In this thesis, the syntheses of several polyfunctionalised cyclohexenones are described. These compounds are analogues of COTC and COMC which also bear structural resemblance to the antheminone and carvotacetone natural products. Initially, the syntheses of six novel compounds from the chiral pool starting material (-)-quinic acid are described. The first four synthetic steps of each sequence were carried out by slight modification of procedures previously reported by the Whitehead research group. As part of the synthetic strategy, the diastereoselective conjugate addition of carbon nucleophiles to several polyfunctionalised cyclohexenones was investigated. The cytotoxicity of four of the synthetic analogues towards A549 non small cell lung cancer cells was investigated by use of an MTT assay. Two of the analogues were found to be more cytotoxic then COMC. The most effective synthetic analogue had an IC50 value of 2.2 μM. This analogue was more cytotoxic than similar molecules that had previously been synthesised by members of the Whitehead research group. Based on the results of the MTT assay, another two analogues were designed and their synthesis from (-)-quinic acid is described. The cytotoxicity of these analogues has yet to be assessed. In summary, the general synthetic strategies developed in this thesis will provide easy access to new analogues of the natural products, enabling the development of new cytotoxic compounds.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:553502 |
| Date | January 2012 |
| Creators | Williams, Katharine |
| Contributors | Whitehead, Roger |
| Publisher | University of Manchester |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://www.research.manchester.ac.uk/portal/en/theses/investigation-of-a-synthetic-approach-to-polyfunctionalised-cyclohexenones-related-to-the-antheminone-and-carvotacetone-natural-products(bab498dd-4ab6-4f07-81f1-72b29cbb2f60).html |
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