Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph.D.)--York University, 2004. Graduate Programme in Chemistry. / Typescript. Includes bibliographical references (leaves 251-269). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNQ99203

As metabolic substrates, ketone bodies provide an alternative to glucose in order to pro- long survival during starvation. A low carbohydrate, high fat diet can be used to promote ketogenesis without fasting, but long-term compliance can be difficult. Dietary ketone bod- ies may be an alternative method to induce ketosis, so the aim of the work in this Thesis was to investigate the metabolism of exogenous ketones. In the first experimental Chap- ter, the effects of ketone ester and salt drinks on blood β-hydroxybutyrate (βHB), glucose, lipids, electrolytes and pH were determined in healthy humans at rest. Blood D-βHB levels were higher following ketone ester drinks, but it was found that total βHB levels with ke- tone salts were similar, as over 50% of βHB delivered in the salt was the L-isoform, which was only slowly removed from the blood. Circulating glucose and lipid concentrations fell following both ketone drinks. Blood pH fell following ketone ester consumption, but rose following ketone salt drinks, whilst both compounds raised blood sodium and chloride, and lowered potassium. Work in the second Chapter investigated the repeatability of ketone es- ter metabolism with food, successive drinks or continuous nasogastric (NG) infusion. Peak D-βHB levels were repeatable between- and within- subjects at rest but were lower after a meal, although blood acetoacetate, breath acetone and urine βHB were unaffected by feed- ing. βHB kinetic parameters were not altered by existing hyperketonemia from successive ketone ester drinks and total βHB uptake was identical when isovolumetric amounts of ketone ester were continuously infused through a NG tube. The third Chapter explored side-effects of ketone drinks: ketone ester drinks decreased appetite compared to isocaloric dextrose; which may have been linked to effects of βHB on enteroendocrine cells. Fur- thermore, both ester and salt drinks were found to be unpalatable, and to cause a few, mild gastro-intestinal effects that increased with intake. As exogenous ketones could be a per- formance enhancing supplement in sport, the fourth Chapter used a survey to investigate supplement use by endurance athletes. The results demonstrated widespread supplement use, which was highest at the elite level. In the final Chapter, the effect of glycogen lev- els on the oxidation of βHB was determined in isolated perfused rat hearts. Low cardiac glycogen levels decreased βHB oxidation and levels of the intermediates of glycolysis and the Krebs cycle, whilst increasing muscle amino acid levels, suggesting that low glycogen may have impaired anaplerosis. In conclusion, this work extends current understanding of the novel physiological ketosis that occurs following exogenous ketone consumption.

Angelman syndrome (AS) is a rare genetic and neurological disorder presenting with severe developmental delay, ataxia, epilepsy, and lack of speech. AS is associated with a neuron-specific loss of function of the maternal UBE3A allele, a gene encoding an E3 ubiquitin ligase. Currently, no cure exists for this disorder; however, recent research using an AS mouse model suggests that pharmacological intervention is plausible, and can alleviate some of the detrimental phenotypes reported in AS patients. Although there is no curative treatment for AS, seizure medication and behavioral therapies are most commonly prescribed in order to minimize symptoms. However, these options only moderately improve quality of life and can cause adverse side effects, such as alterations in mood and cognition following seizure treatment. Unfortunately, epilepsy is a common cause of death in AS and affects greater than 80% of AS patients, with 77% of those patients remaining refractory. The severity of seizures and lack of consistently effective anti-epileptic medications for AS patients demonstrates a considerable need for other therapeutic options. The goal of this work was to evaluate the effects of seizure therapies that have proven beneficial for treating refractory epilepsy in seizure-related disorders. These studies focused specifically on advances in both a pharmacological and dietary therapy evaluated in the AS mouse model. Previous work in our lab has demonstrated the importance of interneurons and GABAergic tone in hippocampal network regulation and cognition. GABA is an important modulator of synaptic plasticity, and learning increases both inhibitory synaptogenesis and GABA release from hippocampal inhibitory neurons. A neuronal excitatory/inhibitory imbalance, coupled with decreased GABAergic tone, altered synaptic plasticity, and impaired cognition have been reported in the AS mouse model. Therefore, we proposed to examine two therapeutic strategies used in seizure treatment – a ketone ester (KE) supplement, which is thought to increase the [GABA]/[glutamate] ratio via alterations in brain metabolism, and ganaxolone, a positive allosteric modulator of GABAA receptors. We evaluated the effects of each therapeutic on learning and cognitive enhancement, alterations in synaptic function, and anticonvulsant activity. We hypothesized that both the KE and ganaxolone would demonstrate anticonvulsant efficacy in both behavioral and chemiconvulsant seizure models. Additionally, as chronic epilepsy has been linked to progressive cognitive and memory impairment which may be related to GABA deficiencies, we hypothesized that both therapeutics would improve cognition and modulate synaptic plasticity (i.e., synaptic function). KE administration produced sustained ketosis and improved motor coordination, learning and memory, and synaptic plasticity in AS mice. The KE was also anticonvulsant and altered brain amino acid metabolism in AS treated animals. Ganaxolone was anxiolytic, anticonvulsant, and improved motor deficits in AS mice. Four weeks of treatment also led to recovery of spatial working memory and hippocampal synaptic plasticity deficits. This study demonstrates that the KE and ganaxolone ameliorate many of the behavioral abnormalities in the adult AS mouse, possibly through modulations of GABAergic tone. These results support clinical investigation of both the KE and ganaxolone in AS, which may lead to the development of a novel treatment for AS patients.

Enantiomerically pure amines have a variety of industrial applications. They are valuable components within the pharmaceutical and agrochemical industry, resolving agents for separation of racemic mixtures by dimeric salt formation and ligands for transition metal catalysts and chemocatalysts. Biocatalysis is increasingly seen as the method of choice for the synthesis of chiral amines. New commercial enzymes being readily available and new screening/evolution technologies allow for enzyme optimisation towards a set of required conditions for chiral amine synthesis. Transaminases are a class of pyridoxal 5’-phosphate (PLP) dependant enzymes that catalyse the reversible transfer of ammonia from an amine donor (e.g. alanine) to a keto acceptor (e.g. acetophenone), allowing the potential for asymmetric methodologies. Transaminases are already well established for the industrial production of α-amino acids and now that research scientists have dealt with some of the problems with equilibrium and substrate/product inhibition, they are being investigated for the industrial application of chiral amines. A multi-enzyme kinetic assay has been utilised for characterisation of newly identified transaminase enzymes in solution phase. Identified transaminases that showed desirable characteristics were cloned and expressed and utilised in the synthesis of amines of interest to industry. Dual enzyme cascade reactions utilising transaminases and either galactose oxidase from Fusarium sp. or monoamine oxidase from Aspergillus niger were used to produce a number of primary and secondary amines in high e.e. and conversion.

The rampant growth of obesity worldwide has stimulated explosive research into human metabolism. Metabolic rate has been shown to be altered by diets differing in macronutrient composition, with low-carbohydrate, ketogenic diets eliciting a significant increase over other interventions. The purpose of this study was to determine the effects of the ketone β-hydroxybutyrate (βHB) on mitochondrial respiration and coupling status in adipose tissue. To explore this, we employed three distinct systems, namely cell, rodent, and human models. In every model, βHB robustly increased mitochondrial respiration. Furthermore, in cultured adipocytes and rodent adipose, we quantified the expression of genes involved in mitochondrial biogenesis and coupling status. We observed that genes involved in mitochondrial biogenesis and uncoupling were significantly higher in models exposed to ketone treatments. In conclusion, ketones increase mitochondrial respiration in cells and mammalian adipose tissue, but not ATP production, indicating greater mitochondrial uncoupling. These findings may partly explain the increased metabolic rate evident in states of elevated ketones and may facilitate the development of novel obesity interventions in the future.

Transfer hydrogenation has been recognized to be an important synthetic method in both academic and industrial research to obtain valuable products including alcohols. Transition metal catalysts based on precious metals, such as Ru, Rh and Ir, are typically employed for this process. In recent years, iron-based catalysts have attracted considerable attention as a greener and more sustainable alternative since iron is earth abundant, inexpensive and non-toxic. In this work, a combination of iron disulfide with chelating bipyridine ligand was found to be effective for the transfer hydrogenation of a variety of ketones to the corresponding alcohols in the presence of a simple base. It provided a convenient and economical way to conduct transfer hydrogenation. A plausible role of sulfide next to the metal center in facilitating the catalytic reaction is demonstrated.

No description available.

The keytones are representative of one of the large groups of compounds of Organic Chemistry. Phenyl-methyl-ketone is the simplest representative of the mixed aliphatic-aromatic ketones. It is a member of a group of compounds which are soporific and hypnotic and are used in medicine as sleep producers and sedatives. It is found to a small extent in coal tar. It has basic properties and is extracted from the heavy oil of coal tar with sulfuric acid. The purpose of this research is to synthesize one of the compounds which is not present in the compilation of the natural lists and to investigate its properties. The compound that is the focus of this research is acetyl acetophenone. It is next to phenyl-methyl-ketone in the group of mixed aliphatic-aromatic ketones. The relation between these two compounds can best be shown by their structural formulae: PHENYL-METHYL-KETONE [see PDF file for formula] [see PDF file for formula] ACETHYL ACETOPHEMONE