Non-enzymatic browning (NEB) due to ascorbic acid degradation is one of the most common reasons the shelf life of many processed foods is reduced. Different methods to minimize or retard the formation of browning pigments have been studied; however, to date, refrigeration is still the most preferable. Unfortunately, the use of low temperatures to preserve food is not always available in many parts of the world. Indeed, an area of concern due to NEB has been identified in meal-ready-to-eat (MRE) individual military rations, specifically diced peaches with syrup. This product was once part of soldiers' menus; however, it was removed due to browning and textural deterioration that occurred when stored under field conditions. We examined two general approaches to reduce NEB: the replacement of ascorbic acid by a more stable form and the use of flavonoids as antibrowning antioxidants in peach systems. These approaches were studied in three objectives. In our first objective, ascorbyl-2-phosphate showed better stability than ascorbic acid at 40°C in peach puree model systems, but not at 50 or 60°C. In the second objective, after the evaluation of the effect of two forms of vitamin C (ascorbic acid and ascorbyl-2-phosphate) and Pycnogenol (0%, 0.01% and 1%) on the quality of diced peaches in retortable pouches, we concluded that neither ascorbyl-2-phosphate nor pycnogenol resulted in improved color or ascorbic acid stability. Finally, in our third objective, after the evaluation of the effect of peach source (fresh, individually quick frozen and canned), addition of calcium chloride, and the addition of a water soluble flavonoid (°-glucosylrutin, °-GR) in diced peaches packaged in retortable pouches stored at 24, 40 and 51°C, there were no significant effects of °-GR on any of the peach sources at 51°C. However, at 40°C, °-GR improved the quality of diced peaches in pouches made of individually quick frozen and canned peaches, but not for fresh peaches. Quality was assessed by color (CIELAB system), which was measured using a handheld colorimeter, and ascorbic acid levels of peaches, which was determined using high performance liquid chromatography. / Master of Science

The use of boron in the synthesis and development of asymmetric methodologies and various biological and medicinal compounds has increased significantly over the last decade. This thesis reports the development of a novel diastereoselective reaction for the α-alkylation of chiral β-borylated esters. We propose that standard deprotonation of chiral β-borylated esters with lithium diisopropylamide (LDA) leads to the formation of a boron"ate" intermediate that upon treatment with an alkylation reagent collapses to provide chiral α, β-substituted boronic esters with a high degree of diastereoselectivity. This reaction is powerful in that a wide range of chiral β-borylated ester substrates can be employed that possess varying degrees of substitution and steric bulk. Results show that the reaction is syn-selective and provides yields of up to 60%, with diastereomeric ratios as high as (9.7:1). Additionally, alkylation products from bulkier tert-butyl esters provide higher DR values compared to those of methyl esters that possess the same β-functional groups. Several techniques were utilized to elucidate the mechanism of this reaction including variations of reaction temperature and equivalents of base, and also real-time analysis of the reaction by ¹¹B NMR experiments. / Master of Science

Pesticides have been suggested to play a role in the development of many neurodegerative diseases including Parkinson's disease and Alzheimer's disease. Additionally, it has been suggested that exposure to pesticides and other environmental chemicals during the early stages of life could result in an increased vulnerability to such substances that could lead to neurotoxicity and degeneration late in life. We hypothesized that exposure to mixtures of certain pesticides could change neurotransmitter levels and cellular oxidative stress and that this would be greater in mice exposed early and later in life than mice exposed only as adults. We studied the effects of permethrin (PR) (a pyrethroid type I) and endosulfan (EN) (an organochlorine) on the levels of catecholamines, indolamines, acetylcholinesterase, lipid peroxidation and α-synuclein in the brain of mice. These pesticides have different structures but both are known to modify the kinetics of voltage-sensitive ion channels and calcium ion flux/homeostasis that could affect the release of several neurotransmitters. The study consisted of two experiments: In the first experiment, adult C57Bl/6 mice (7-9 months old) were injected, intraperitoneally, with the following treatments: EN 4.3, 2.15 mg/kg; PR 150, 15 mg/kg and their mixtures EN 4.3 + PR 150 and EN 2.15 + PR 15 mg/kg. Mice were sacrificed 24 hrs after the last injection. In the second experiment, doses consisted of EN 0.7, 1.4 mg/kg, PR 1.5, 15 mg/kg and their mixtures EN 0.7 + PR 1.5 mg/kg and EN 1.4 + PR 15 mg/kg were given to juvenile mice intraperitoneally daily during a period of two weeks from postnatal day 5 to 19. Mice were then, left undisturbed with their dams. Re-challenge was performed when mice were 7-9 months old and dosages of EN 4.3, 2.15 mg/kg, PR 150, 15 mg/kg and their mixtures, EN 4.3 + PR 150 and EN 2.15 + PR 15 mg/kg were given intraperitoneally every other day during a period of two weeks to match the treatments when pesticide exposure was only as adults. Mice were sacrificed 24 hrs after the last injection. The corpora striatum was extracted and analyzed by HPLC for catecholamines (dopamine, DOPAC, homovalinic acid and norepinephrine) and indolamines (serotonin and 5-HIAA). In general low doses of permethrin and endosulfan alone and in combination (EN 2.15 + PR 15 mg/kg) altered the levels of catecholamines and indolamines in both studies with adult mice and mice dosed as juveniles and re-challenged as adults. Catecholamine and indolamines levels were affected to a greater extent in the adult mice than in mice dosed as juveniles and re-challenged as adults, when compared to controls. Acetylcholinesterase was increased under both exposure situations but again adult mice seemed to be more affected than mice dosed as juveniles and re-challenged as adults. Because reactive oxygen species have been implicated in the development of Parkinson's disease, and are known to cause degradation of certain neurotransmitters, we monitored the levels of lipid peroxides in brain cortex as an indicator of free radical tissue damage. The peroxide levels were measured by thiobarbituric acid reactive products (TBARS). Increased levels of lipid peroxides were significant in the low dose treatment groups of the adult study. However, there seemed to be a pattern between the levels of dopamine and DOPAC in the striatum and the levels of peroxidation in cortex. The presence of dopamine metabolites appeared to be related to high levels of peroxidation within the basal ganglia and up-regulation of proteins such as α-synuclein. Western blots of α-synuclein in both experiments of the study showed intense double and triple bands that corresponded to aggregated α-synuclein. In general, when compared with controls, mice dosed as juveniles and re-challenged as adults did not alter the above parameters as much as mice dosed only as adults. Instead, the mice first dosed as juveniles seemed to develop an adaptation response to the later exposure of these pesticides. Taking all these results into account, early exposure and re-challenge with permethrin and endosulfan in this study appeared to induce a protective response against neurochemical changes in the brain of these mice. In addition, low doses of these pesticides and the low dose combination mixture seem to exert an effect on the parameters studied. Therefore, exposure to pesticides such as endosulfan and permethrin and their combinations could make a contribution towards the initiation or aggravation of biochemical neurodegenerative diseases such as Parkinson's and Alzheimer's diseases. / Master of Science

Yes / The first example of an intramolecular hydroarylation of 1,6-en-α-chloro-enamides was achieved by a palladium-catalysed ligand-free reductive Heck cycloisomerisation with no competing Heck-cyclised by-product.

Yes / Ynamide, is an understudied but attractive class of alkynes, activated by the donating ability of the nitrogen adjacent to alkynes. With the nucleophilicity on β-carbon and the electrophilicity on α-carbon of ynamides, this review summarizes the syntheses of ynamides and miscellaneous reactions - oxidation, rearrangement, cyclization, and cycloaddition to construct complicated heterocyclic rings. The synthetic methodologies were further applied into natural products synthesis, e.g. marinoquinolines A and C, aplidiopsamine A, rigidin A, and 7-azaserotonin derivative. / We thank National Science Foundation of China (NSFC) (21462004), State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (CMEMR2014-A04), 2015 GXNSFBA (139032), GXNU, and Newton International Fellowship granted by Royal Society.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第25132号 / 理博第5039号 / 京都大学大学院理学研究科化学専攻 / (主査)教授 依光 英樹, 教授 畠山 琢次, 教授 松永 茂樹 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 新制・課程博士 / 博士(農学) / 甲第25330号 / 農博第2596号 / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 木岡 紀幸, 教授 阪井 康能, 教授 栗原 達夫 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

京都大学 / 新制・課程博士 / 博士(農学) / 甲第25333号 / 農博第2599号 / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 小川 順, 教授 矢﨑 一史, 教授 栗原 達夫 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

This thesis is a study of α-(4-aminophenylsulfonyl)-acetophenone derivatives; n-diphenylmethyl and n-fluorenyl piperidines.

Le sujet de thèse s’inscrit dans le cadre des stratégies visant à organiser des nanostructures, plus particulièrement les stratégies visant à augmenté la densité d’information dans les médias magnétique. Les techniques de synthèse en chimie douce utilisés au LPCNO-INSA on permet d’élaborer des nano-bâtonnets monocristallins de cobalt dont les propriétés ferromagnétiques en termes d’anisotropie et d’aimantation présentent un grand intérêt pour des applications dans le domaine du stockage magnétique. La maitrise de la croissance de ces nano-bâtonnets de Co organisés perpendiculairement sur un substrat peut permettre de réaliser un média de forte densité. Nous avons dans un premier temps vérifié la croissance perpendiculaire de nano bâtonnets de cobalt monocristallins sur une couche continue de Pt (111) épitaxiée sur un substrat de saphir (Al2O3) et montré que cette combinaison de deux types de dépôts (physique et chimique) donne effectivement lieu à un réseau dense et perpendiculaire de bâtonnets de Co. Pour but d’organiser cette croissance et découpler physiquement les bâtonnets de Co nous avons alors étudié la croissance de ces bâtonnets de Co sur des îlots 3D métalliques de Pt et de Co.En première partie nous avons étudié la structure cristalline, La morphologie, les distributions en taille et l’état des contraintes des îlots de Pt et Co déposée sur la surface (0001) du saphir et la surface (001) du MgO par pulvérisation cathodique. Et en deuxième partie, nous avons étudié la croissance des nano bâtonnets de Co sur les ilots de Pt et de Co maitrisés dans l’étape précédente / The subject of this thesis is to be part of strategies in order to organize nanostructures, particularly strategies to increase information density in magnetic media. The synthesis techniques used in chemistry (LPCNO-INSA laboratory) is allowed to develop monocrystalline nanorods of cobalt whose ferromagnetic properties in terms of anisotropy and magnetization present a great interest for applications in the field of magnetic storage. The success in controling the growth of these nanorods arranged perpendicularly on a substrate can lead to achieve a high density media. We tested the perpendicular growth of monocrystalline nanorods of cobalt on a continuous and epitaxial layer of Pt (111) grown on a substrate of sapphire (Al2O3) and showed that this combination of two types of deposits (physical and chemical) give actually a dense and perpendicular network of Co nanorods. In the aim to organizing this growth and decoupling physically the nanorods we studied the growth of these Co nanorods on 3D metallic islands of Pt and Co. In the first part we studied the crystal structure, morphology, size distributions and the stress state of Pt and Co islands deposited on the surface (0001) of sapphire and (001) surface of MgO by sputtering. And in the second part, we studied the growth of Co nanorods on a Pt and Co islands mastered in the previous step