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dc.contributor.advisorManley-Harris, Merilyn
dc.contributor.authorOwens, Adrian
dc.date.accessioned2016-11-29T22:15:55Z
dc.date.available2016-11-29T22:15:55Z
dc.date.issued2016
dc.identifier.citationOwens, A. (2016). The kinetics of the dissociation of dihydroxyacetone dimer in aprotic media (Thesis, Master of Science (MSc)). University of Waikato, Hamilton, New Zealand. Retrieved from https://hdl.handle.net/10289/10774en
dc.identifier.urihttps://hdl.handle.net/10289/10774
dc.description.abstractThe dissociation of the dihydroxyacetone (DHA) dimer in mānuka honey has previously been proposed to be the rate determining step in the overall conversion of DHA to methylglyoxal, the agent reported to be responsible for the non-peroxide anti-bacterial activity displayed by mānuka honey. The ¹H and ¹³C NMR spectra for the DHA dimer and the DHA monomer in DMSO-d6 were assigned using 1D and 2D NMR spectroscopy. ¹H and ¹³C NMR spectroscopy were utilised to investigate the kinetics of the dissociation of the DHA dimer in DMSO-d6, an anhydrous solvent chosen to mimic the dehydrating conditions present in the honey matrix. Four series of kinetic experiments were conducted, one without catalysis, one with D₂O catalysis, one with CD₃COOD catalysis and one with CD₃COOD/CD₃COOD catalysis. Each of these experiments obtained the equilibrium constant, K and the rate constants k, k₁ and k₋₁ for the dissociation of the DHA dimer under different conditions that may be present in the honey matrix, with the exclusion of the CD₃COOD/CD₃COOD catalysed experiments which were conducted as part of the investigation to determine a proposed reaction mechanism. Two reaction intermediates were observed in the CD₃COOD catalysed experiments, they were characterised and provided supporting evidence for a proposed acid-catalysed reaction mechanism for the DHA dimer dissociation. The absence of reaction intermediates in the D₂O catalysed experiments provided supporting evidence for a proposed base-catalysed reaction mechanism for the DHA dimer dissociation. Reaction mechanisms for the DHA dimer dissociation in DMSO-d6 and mānuka honey were proposed based on the findings of previous studies and the findings associated with the kinetic experiments conducted in this study.
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.publisherUniversity of Waikato
dc.rightsAll items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.
dc.subjectDihydroxyacetone
dc.subjectKinetic
dc.titleThe kinetics of the dissociation of dihydroxyacetone dimer in aprotic media
dc.typeThesis
thesis.degree.grantorUniversity of Waikato
thesis.degree.levelMasters
thesis.degree.nameMaster of Science (MSc)
dc.date.updated2016-03-18T00:06:46Z
pubs.place-of-publicationHamilton, New Zealand


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