School of Chemistry - Theses
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ItemRadiolabelled peptides and amino acids for PET imaging of cancer( 2019)Cell surface receptors, which are overexpressed in cancerous tumours, are feasible molecular targets for tumour imaging. The transmembrane G-protein coupled receptor CXCR4 is overexpressed in tumours and has a crucial role in organ-specific metastasis of tumour cells. Cyclic pentapeptides such as FC131 and analogues have been developed to bind with high affinity and specificity to CXCR4. Unfortunately, when FC131 is radiolabelled and evaluated as a PET imaging agent, it demonstrates high retention in the liver due to its lipophilic character. Sulfonation of aromatic groups, such as the phenolic group in tyrosine, results in a significant reduction of a peptide’s lipophilic character. Evaluation of sulfonated FC131 peptide analogues as PET imaging agents has been undertaken. In addition to radiolabelled peptides, PET imaging using amino acids has shown promise for tumour detection. 18F containing radiolabelled amino acids are transported across the cell membranes by amino acid transporter proteins. As such, several approaches to synthesise fluorothreonine, fluoroaspartic acid and fluorotyrosine analogues have been examined.
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ItemStudies of the interaction of metal complexes with ligands and biomolecules in the gas phase using mass spectrometry( 2005)Introduction of soft ionization techniques, such as electrospray ionization (ESI), has resulted in extensive use of mass spectrometry based techniques to study biomolecules in the gas phase. Despite thorough studies of the gas-phase chemistry of even-electron biomolecules, the examination of their odd-electron counterparts has to this point been much less extensive due to the inefficiency of ESI in generating such species. Among various methods that could be employed to generate and study odd-electron biomolecules in the gas phase, redox processes involving metal ions and homolytic cleavage of metallated amino acid or peptide derivatives would be attractive from a chemical perspective since, in principle, a wide range of metals and biomolecules or biomolecule derivatives could be explored. An important aspect of these approaches is that they can be carried out on a wide range of tandem mass spectrometers equipped with electrospray ionization and collision induced dissociation capabilities. (For complete abstract open document)