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dc.contributor.authorHu, Di
dc.contributor.otherQueen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))en
dc.date2010-02-03 15:42:39.67en
dc.date.accessioned2010-02-03T22:26:59Z
dc.date.available2010-02-03T22:26:59Z
dc.date.issued2010-02-03T22:26:59Z
dc.identifier.urihttp://hdl.handle.net/1974/5426
dc.descriptionThesis (Master, Chemistry) -- Queen's University, 2010-02-03 15:42:39.67en
dc.description.abstractChapter 1 Hydrocarbon autoxidation, a free radical chain reaction, is believed to play a key role in the onset and developments of most degenerative diseases and disorders. The two propagating steps: 1) H-atom abstraction from the hydrocarbon by a hydrocarbon-derived peroxyl radical, and 2) addition of oxygen to the resultant alkyl radical to form a new peroxyl, play a role in determining the rate of hydrocarbon autoxidation, as well as the regio- and stereochemistry of the product hydroperoxides. In the current study, we carried out a set of calculations to provide a detailed framework for understanding the mechanism of the first two steps of autoxidation. Chapter 2 Radical-trapping chain-breaking antioxidants inhibit hydrocarbon autoxidation. Phenols are the prototypical radical-trapping antioxidants and are employed in nature, as well as in industry, to inhibit the autoxidation of hydrocarbons. The mechanism of inhibiting radical chain propagation has recently been suggested to be a PCET on the basis of theoretical calculations. It has been demonstrated that the antioxidant activitiy of phenols is increased in the presence of either protic acids or alcohols, but the basis of this acceleration is not well understood. In the current study, we used computational methods to investigate the effects of acids and alcohols on the PCET pathway for the reaction of phenol with a peroxyl radical. Chapter 3 The antibiotic pyrrolnitrin [3-chloro-4-(2’-nitro-3’-chlorophenyl) pyrrole] (PRN) is biosynthesized from L-tryptophan in four steps, catalyzed by the enzymes PrnA, B, C and D encoded by the prn operon. Two of the four gene products, PrnA and PrnC, are flavin-dependent halogenases, a recently discovered and highly interesting class of enzymatic halogenation catalysts. Their activities have never been unequivocally demonstrated by reconstitution of the activity from a recombinant protein. Herein, we report the results of our efforts to clone the genes encoding PrnA and PrnC, and overexpress, isolate and purify the proteins from E. coli. We were able to successfully reconsistute halogenation activity of both and have obtained the first kinetic data for PrnC, which shows kinetics similar to other flavin-dependent halogenases, along with substrate inhibition.en
dc.format.extent6932481 bytes
dc.format.mimetypeapplication/pdf
dc.languageenen
dc.language.isoenen
dc.relation.ispartofseriesCanadian thesesen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectLipid Autoxidationen
dc.subjectPropagationen
dc.subjectBeta-Fragmentationen
dc.subjectComputationalen
dc.subjectPCETen
dc.subjectOxygen Dependent Halogenaseen
dc.subjectPyrrolnitrinen
dc.subjectPrnCen
dc.subjectKineticen
dc.subjectE,colien
dc.titleComputational Studies of Lipid Autoxidation and Solvent-Mediated Antioxidant Activity and a Kinetic Study of a Halogenase in the Pyrrolnitrin Biosynthetic Pathwayen
dc.typeThesisen
dc.description.degreeMasteren
dc.contributor.supervisorPratt, Derek A.en
dc.contributor.departmentChemistryen


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