Title from title page of PDF (University of Missouri--St. Louis, viewed March 22, 2010). Non-Latin script record Includes bibliographical references.

Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2008. / Includes bibliographical references (leaves 77-79). Also available online.

Despite progress in the metal-catalyzed synthesis of aromatic heterocycles, annulation routes towards 6-membered heterocycles remain underdeveloped. Specifically, routes towards pyridines are rare in spite of the prevalence of this moiety in novel drug candidates. Our initial efforts towards pyridines featured oximes as competent nucleophiles in the intramolecular, 6-exo dig annulation of alkynes using Brønsted acid catalysis. Two of the oxidation states required for subsequent aromatization are contained within the oxime via loss of water. An extension of this chemistry is presented and discussed, and involves the intramolecular metal-catalyzed 6-endo dig annulation of analagous alkynyl-oximes. Additionally, the discovery of a 5-exo dig annulation of related systems is discussed.

Distillation technology involves capital- and energy-intensive processes for light olefin/paraffin separation. Global demand for propylene has already exceeded 110 million tons per year. Therefore, distillation processes used for the separation of C3H6/C3H8 should be replaced or debottlenecked with more efficient and cost-effective technology. In the last three decades, membrane-based gas separation processes have successfully emerged, thus competing with conventional separation processes. Membranes potentially offer lower capital investment and operation cost than distillation columns. In this study, the use of advanced membrane materials for C3H6/C3H8 separation was investigated. Three novel triptycene-based polyimides were synthesized by Dr. Bader Ghanem from one diamine monomer, namely 2,6-dihydroxy-3,7-diaminotriptycene (DTA1-OH), and three dianhydride monomers, (i) non-substituted triptycene tetracarboxylic dianhydride (TDA), (ii) 9,10-dimethyltriptycene tetracarboxylic dianhydride (TDA1) and (iii) 9,10-iso-propyltriptycene tetracarboxylic dianhydride (TDAi3). It is important to note that polyimide membranes based on triptycene dianhydrides and triptycene diamines have never been reported in the literature before. Pure-gas permeability coefficients of He, H2, N2, O2, CO2, CH4, C3H6, and C3H8 were determined at 2 bar and 35 °C. Furthermore, C3H6 and C3H8 gas sorption isotherms were measured by gravimetric techniques, and experimental data were collected up to 7 bar at 35 °C. TDA-DAT1-OH, TDA1-DAT1-OH, TDAi3-DAT1-OH exhibited C3H6 permeability of 12.1, 16.6, and 5.64 Barrer with pure-gas C3H6/C3H8 selectivity of 35.7, 29.6, and 32.8 respectively. These properties exceeded the 2003 pure-gas upper bound for C3H6/C3H8. The BET surface area increased in the order of TDA-DAT1-OH (437 m2/g) < TDAi3-DAT1-OH (467 m2/g) < TDA1-DAT1-OH (557 m2/g). The frecational free volume (FFV) increased in the order of TDAi3-DAT1-OH (0.25) < TDA-DAT1-OH (0.28) < TDA1-DAT1-OH (0.30). TDA1-DAT1-OH (109 μm) showed less and slower physical aging than TDA-DAT1-OH (94 μm) after 60 days, where the O2 and CO2 permeability of both polyimides decreased by about 40% and 69%, respectively. After 30 days, TDAi3-DAT1-OH displayed the highest selectivity gain relative to its counterparts and exceeded the 2008 upper bound for CO2/CH4. TDA1-DAT1-OH exhibited 7-fold higher C3H6 permeability coupled with almost 3-fold higher C3H6/C3H8 selectivity relative to a previously reported commercial polyphenylene oxide (PPO) membrane.

Gas chromatographic acquisition of representative 'Total' cellular fatty acid profiles from bacteria or bacteria-containing samples (e.g., environmental or clinical materials) tends to be dependent on the method used to released the fatty acids and convert them to derivatives suitable for analysis. Alkaline saponification or interesterification methods, while preserving acid-sensitive components such as cyclopropane fatty acids, are often insufficient to release amide-linked components, such as hydroxylated fatty acids. Acid-catalyzed hydrolyses or interesterifications, on the other hand, while more efficiently releasing the predominantly amide-linked hydroxylated components, have been shown to cause severe and unpredictable degradation of cyclopropane fatty acids. We report studies of a single-tube method involving sequential alkaline/acid release of fatty acids in which fatty acids released by the alkaline step are partitioned into an organic epiphase during the aqueous acid hydrolysis step. After hydrolysis, the epiphase and the released fatty acids are extracted into an hypophasic solvend and esterified at moderate temperature under relatively low acid concentrations. Under these conditions, cyclopropane as well as hydroxylated fatty acids are recovered in high yield.

The effects of supplementation of the leucine metabolite β-hydroxy-β- methylbutyrate (HMB) were examined in a resistance training study. Thirty- nine men and 36 women between the ages of 20-40 y were randomized to either a placebo (P) supplemented or HMB supplemented (3.0 g HMB/d) group in two gender cohorts. All subjects trained three times per week for 4 wk. In the HMB group, plasma creatine phosphokinase levels tended to be suppressed compared to the placebo group following the 4 wk of resistance training (HMB:174.4 ± 26.8 to 173.5 ± 17.0 U/L; P:155.0 ± 20.8 to 195.2 ± 23.5 U/L). There were no significant differences in strength gains based on prior training status or gender with HMB supplementation. The HMB group had a greater increase in upper body strength than the placebo group (HMB:7.5 ± 0.6 kg; P:5.2 ± 0.6 kg; P = 0.008). The HMB groups increased fat-free weight by 1.4 ± 0.2 kg and decreased percent fat by 1.1% ± 0.2% while the placebo groups increased fat-free weight by 0.9 ± 0.2 kg and decreased percent fat by 0.5% ± 0.2% (fat-free weight P = 0.08, percent fat P = 0.08, HMB compared to placebo). In summary, this is the first short-term study to investigate the roles of gender and training status on the effects of HMB supplementation on strength and body composition. This study showed, regardless of gender or training status, HMB may increase upper body strength and minimize muscle damage when combined with an exercise program.

No description available.

Consumption of β-hydroxy β-methylbutyrate (HBM), a leucine metabolite, alters muscle composition and metabolism leading to strength and agility improvements in human athletes. To determine if HMB affects athletic performance and muscle function in horses, Thoroughbred geldings were fed a control (CON; n=5) or HMB (n=6) supplement (30 mg/kg/day) for 6 weeks prior to completing a standardized exercise test (SET). Gluteus medius (GM) muscle samples were obtained before the SET for fiber-typing and venous blood was collected before and immediately upon completion of the SET for lactate measurements. Heart rate (HR), biceps femoris (BF) and semitendinosus (ST) surface electromyograms, and fore- and hindlimb metacarpophalangeal joint angles were captured for the duration of the SET. Results demonstrate that HMB supplementation increased (P < 0.05) the percentage of type IIA muscle fibers in the GM with a corresponding decrease (P < 0.05) in type IIX fibers. The percentage of type I fibers was unaffected by diet. Supplementation with HMB did not result in any significant effects on performance, muscle function or biomechanical properties by comparison to CON. Increasing treadmill speed resulted in an increase (P < 0.05) in stride length and maximal extension angle of the fore fetlock, and a shortening (P < 0.05) of the stance phase of the gait cycle. Integrated EMG (iEMG) increased (P < 0.05) with increasing treadmill speeds for both the BF and ST, with the BF exhibiting greater iEMG values than the ST. In summary, HMB increased the percentage of type IIA fibers which did not translate into immediate, improved athletic performance / Master of Science / Muscles depend on their fibers, innervation, energy supply, and blood flow to contract. Failure to meet one or more of these requirements precludes muscle tissue from performing work, situation termed fatigue. Identification of fatigue indicators is of interest to the horse industry for a number of reasons, including horse and human safety, prevention of unnecessary expenses, and general public opinion of the sport disciplines. Diet supplementation with legal, performanceenhancing compounds is of interest to riders and horse owners alike. Molecules such as betahydroxy beta-methylbutyrate (HMB) improve muscle function, protein synthesis, and muscle tissue repair. Assessment of the athletic capacity and performance of horses by evaluating fatigue indicators favors responsible training regimes. Techniques to achieve this goal include muscle sampling, biochemical, electromyographic, and biomechanical analysis. We hypothesized that dietary supplementation of HMB would have positive effects on the athletic performance of horses. This study evaluated the effects of 45-day HMB supplementation on muscle fiber composition, muscle performance, and rates of fatigue in adult Thoroughbred horses by use of a high-speed treadmill. Muscle biopsies, blood lactate, high-speed video captures, and electromyography were analyzed. These analyses revealed that HMB supplementation increased the number of fatigue-resistant fibers in muscles but caused no substantial, immediate improvements on the athletic performance of horses.

Les aldéhydes sont des produits chimiques importants dans la synthèse organique, en raison de leurs vastes applications dans les cosmétiques, les produits pharmaceutiques et les herbicides. De plus, ils peuvent être convertis en composés à valeur ajoutée tels que des tensioactifs, des polymères, etc. Classiquement, les aldéhydes sont produits par hydroformylation ou ozonolyse réductrice des alcènes. Cependant, les deux méthodes souffrent de l'utilisation de catalyseurs coûteux et de ligands sophistiqués (hydroformylation) ou de la nécessité d'un procédé à forte intensité énergétique (ozonolyse). En conséquence, le développement d'approches plus durables pour la production d'aldéhydes est hautement souhaitable.Dans ce contexte, nous avons développé deux méthodes pour produire des aldéhydes à partir de dérivés d’acides gras insaturés. La première voie consiste à préparer des a-hydroxycétones grasses à partir de 1,2-diols et les couper pour obtenir des aldéhydes avec de bons rendements. Dans cette voie, deux systèmes catalytiques (homogènes et hétérogènes à base de métaux) ont été développés pour oxyder les diols vicinaux en a-hydroxycétones correspondantes. La coupure de ces espèces a été effectuée par un procédé de rétro-benzoin utilisant des sels de thiazolium thermiquement stables et les aldéhydes ont été récupérés par distillation réactive. La seconde voie repose sur la décomposition des ß-hydroxy hydroperoxydes gras facilement préparés à partir d'oléate de méthyle époxydé. De plus, la décomposition de l'espèce peroxyde a été étudiée dans des conditions thermiques pour donner des aldéhydes. Enfin, la coupure des 1,2-dicétones gras et la valorisation des aldéhydes ont également été étudiés pour conduire aux esters correspondants pouvant être utilisés comme monomères / Aldehydes are important chemicals in organic synthesis, due to their vast applications in cosmetics, pharmaceuticals and herbicides. Moreover, they can be converted to value-added compounds such as surfactants, polymers, etc. Conventionally, aldehydes are produced through hydroformylation or reductive ozonolysis of alkenes. However, both methods suffer from the use of expensive catalyst and sophisticated ligands (hydroformylation) or the requirement of high energy intensive process (ozonolysis). As a result, the development of more sustainable approaches for the production of aldehydes is highly desirable.In this context, we have developed two methods to produce aldehydes from unsaturated fatty acid derivatives. The first route involves the preparation of fatty a-hydroxyketones from 1,2-diols and their cleavage to give aldehydes with good yields. In this route, two catalytic systems (metal-based homogeneous and heterogeneous) have been developed to oxidize vicinal diols to corresponding a-hydroxyketones. The cleavage of these species has been carried out through a retro-benzoin process using thermally stable thiazolium salts and the aldehydes were recovered by reactive distillation. The second route relies on the decomposition of fatty ß-hydroxy hydroperoxides that are easily prepared from epoxidized methyl oleate. Moreover, the decomposition of the peroxide species was studied under thermal conditions to give aldehydes. Finally, the cleavage of fatty 1,2-diketones and the valorization of aldehydes were also studied to give the corresponding esters that could be used as monomers

&amp / #945 / -Hydroxy phosphonates are versatile building blocks for the synthesis of many biologically active compounds that display antiviral, antibacterial, anticancer, pesticide activities beside their enzyme inhibitory activities such as they are the inhibitors of rennin or human immunodeficiency virus (HIV) protease and polymerase. Benzaldehyde lyase is able to catalyze not only C-C bond formation reactions but also C-C bond breaking reactions with high enantioselectivity that brings about the development of new synthetic methodologies for the synthesis of hydroxy ketones which are the key intermediates in the synthesis of many biologically active compounds due to the versatility of stereogenic center for developing structural diversity. There are several synthetic methodologies for the synthesis of hydroxy phoshonates however, in this work we have achieved the synthesis of hydroxy phoshonates through C-C bond forming reactions catalyzed by Benzaldehyde lyase that offers the use of green methodologies. Moreover, we have achieved the synthesis of hydroxy ketones which are versatile building blocks in the synthesis of many biologically active compounds via the immobilization of BAL enzyme on superparamagnetic solid support with high yield and high enantioselectivity.