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G protein-coupled receptor (GPCR) genes are large gene families in every animal, sometimes making up to 1-2% of the animal's genome. Of all insect GPCRs, the neurohormone (neuropeptide, protein hormone, biogenic amine) GPCRs are especially important, because they, together with their ligands, occupy a high hierarchic position in the physiology of insects and steer crucial processes such as development, reproduction, and behavior. In this paper, we give a review of our current knowledge on Drosophila melanogaster GPCRs and use this information to annotate the neurohormone GPCR genes present in the recently sequenced genome from the honey bee Apis mellifera. We found 35 neuropeptide receptor genes in the honey bee (44 in Drosophila) and two genes, coding for leucine-rich repeats-containing protein hormone GPCRs (4 in Drosophila). In addition, the honey bee has 19 biogenic amine receptor genes (21 in Drosophila). The larger numbers of neurohormone receptors in Drosophila are probably due to gene duplications that occurred during recent evolution of the fly. Our analyses also yielded the likely ligands for 40 of the 56 honey bee neurohormone GPCRs identified in this study. In addition, we made some interesting observations on neurohormone GPCR evolution and the evolution and co-evolution of their ligands. For neuropeptide and protein hormone GPCRs, there appears to be a general co-evolution between receptors and their ligands. This is in contrast to biogenic amine GPCRs, where evolutionarily unrelated GPCRs often bind to the same biogenic amine, suggesting frequent ligand exchanges ("ligand hops") during GPCR evolution. (c) 2006 Elsevier Ltd. All rights reserved.

Inhibiting the formation of ice is an essential process commercially, industrially, and medically. Compounds that work to stop the formation of ice have historically possessed drawbacks such as toxicity or prohibitively high active concentrations. One class of molecules, ice recrystallization inhibitors, work to reduce the damage caused by the combination of small ice crystals into larger ones. Recent advances made by the Ben lab have identified small molecule carbohydrate analogues that are highly active in the field of ice recrystallization and have potential in the cryopreservation of living tissue. A similar class of molecules, kinetic hydrate inhibitors, work to prevent the formation of another type of ice – gas hydrate. Gas hydrates are formed by the encapsulation of a molecule of a hydrocarbon inside a growing ice crystal. These compounds become problematic in high pressure and low temperature areas where methane is present - such as an oil pipeline. A recent study has highlighted the effects of antifreeze glycoprotein, a biological ice recrystallization inhibitor, in the inhibition of methane clathrates. Connecting these two fields through the synthesis and testing of small molecule ice recrystallization inhibitors in the inhibition of methane hydrates is unprecedented and may lead to a novel class of compounds.

Aluminum- and gallium-bridged ansa-zirconocene compounds (Pytsi)Al[1]ZCP (31a) and (Pytsi)Ga[1]ZCP (31b) containing a bulky trisyl-based ligand with a pyridyl donor group [Pytsi = -C(SiMe3)2SiMe2(2-C5H4N)] were synthesized in 31% and 40% yield, respectively, by the reaction of (Pytsi)ECp2 [E = Al (29a), Ga (29b)] with Zr(NMe2)4 followed by reaction with Me3SiCl. Compounds 29a and 29b were prepared by the reaction of (Pytsi)ECl2 [E = Al (28a), E = Ga (28b)] with two equivalents of NaCp. The molecular structures of 29a and 29b were elucidated in solution by 1H and 13C NMR spectroscopy. Species 31a was characterized by multinuclear NMR spectroscopy while 31b was characterized by CHN elemental analysis, 1H and 13C NMR spectroscopy and mass spectrometry. Both species are the only known examples of aluminum- and gallium-bridged ansa-zirconocenes. Compound 31b in combination with MAO was applied and shown to be highly active for ethylene polymerization at room temperature. The activity of 31b was compared to that obtained for Cp2ZrCl2 using a glass reactor system and was found to be comparable. The influence of precatalyst concentration and ethylene pressure on activity of 31b was studied.

Les amines, dont plus de 60 sont réglementées au Québec, sont largement utilisées dans plusieurs secteurs industriels. Elles peuvent causer une grande variété de problèmes de santé chez les travailleurs exposés. L'évaluation de l'exposition professionnelle pose un défi puisque les méthodes disponibles d'échantillonnage et d'analyse sont spécifiques à une substance ou à la famille de cette substance et sont souvent compliquées à utiliser. Le projet visait le développement d'un système d'échantillonnage et d'une méthode d'analyse pour la détermination simultanée de sept amines parmi les plus susceptibles d'être retrouvées dans les milieux de travail québécois incluant des amines aliphatiques, des amines aromatiques et des alcoolamines. Le système d'échantillonnage développé utilise des cassettes de 37 mm munies d'un filtre en fibres de verre imprégné d'acide sulfurique. Immédiatement après l'échantillonnage, le filtre est transféré dans une jarre contenant une solution de chlorure de dansyle. Ce réactif est utilisé pour la dérivation parce qu'il forme des sulfonamides aromatiques fluorescentes et faciles à protoner, permettant l'analyse subséquente par CLHP-UV/FL ou CLHP/ESI-SM. Le dérivé dansylé du 1-(2-méthoxyphényl)pipérazine (MOPIP) a été utilisé comme étalon interne en étant directement ajouté sur un filtre lors de l'échantillonnage. L'efficacité de récupération du système d'échantillonnage développé est près de 100 % pour toutes les amines avec des claquages inférieurs à 1 %. L'incertitude étendue de la méthode varie entre 10 % et 18 % selon l'amine et le mode de détection. L'analyse de routine des produits est possible jusqu'à des limites de quantification inférieures de l'ordre de 0,1 µg/mL. L'analyse à haute sensibilité permet, quant à elle, de diminuer les limites de quantification de deux ordres de grandeur. Cette nouvelle stratégie sera utile dans l'évaluation de la qualité de l'air ambiant dans les milieux de travail étant donné qu'elle comprend un système d'échantillonnage unique indépendant de l'amine à quantifier. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Amine aromatique, Amine aliphatique, Alcoolamine, Analyse simultanée, Analyse de l'air.

Aluminum- and gallium-bridged ansa-zirconocene compounds (Pytsi)Al[1]ZCP (31a) and (Pytsi)Ga[1]ZCP (31b) containing a bulky trisyl-based ligand with a pyridyl donor group [Pytsi = -C(SiMe3)2SiMe2(2-C5H4N)] were synthesized in 31% and 40% yield, respectively, by the reaction of (Pytsi)ECp2 [E = Al (29a), Ga (29b)] with Zr(NMe2)4 followed by reaction with Me3SiCl. Compounds 29a and 29b were prepared by the reaction of (Pytsi)ECl2 [E = Al (28a), E = Ga (28b)] with two equivalents of NaCp. The molecular structures of 29a and 29b were elucidated in solution by 1H and 13C NMR spectroscopy. Species 31a was characterized by multinuclear NMR spectroscopy while 31b was characterized by CHN elemental analysis, 1H and 13C NMR spectroscopy and mass spectrometry. Both species are the only known examples of aluminum- and gallium-bridged ansa-zirconocenes. Compound 31b in combination with MAO was applied and shown to be highly active for ethylene polymerization at room temperature. The activity of 31b was compared to that obtained for Cp2ZrCl2 using a glass reactor system and was found to be comparable. The influence of precatalyst concentration and ethylene pressure on activity of 31b was studied.

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Carbon dioxide (CO₂) capture and sequestration (CCS) at fossil-fueled power plants is a critical technology for CO₂ emissions mitigation during the transition to a sustainable energy system. Post-combustion amine scrubbing is a relatively mature CO₂ capture technology, but barriers to implementation include high capital costs and energy requirements that reduce net power output by 20-30%. Capture energy requirements are typically assumed constant, but work investigates whether flexibly operating amine scrubbing systems in response to electricity market conditions can add value to CO₂ capture facilities while maintaining environmental benefits. Two versatile optimization models have been created to study the electricity system implications of flexible CO₂ capture. One model assesses the value of flexible capture at a single facility in response to volatile electricity prices, while the other represents a full electricity system to study the ability of flexible capture to meet electricity demand and reliability (ancillary) service requirements. Price-responsive flexible CO₂ capture has limited value at market conditions that justify CO₂ capture investments. Solvent storage can add value for price arbitrage by allowing flexible operation without additional CO₂ emissions, but only with favorable capital costs. The primary advantage of flexible CO₂ capture is an increased ability to provide grid reliability services and improve grid resiliency at minimum and maximum electricity demand. Flexibility mitigates capacity shortages because capture energy requirements need not be replaced, and variable capture at low demand helps respond to intermittent renewable generation. / text

In chapter 1 the principles behind circular dichroism spectroscopy and exciton coupled circular dichroism spectroscopy are outlined, and examples are cited that illustrate the utility of these methods in the determination of absolute configuration and ee of chiral amines. This provides background and context for this thesis, which mostly pertains to the sensing of chirality in amines. An exciton coupled circular dichroism method based on the induction of helical chirality in an organometallic host for sensing chiral amines is presented in chapter 2. The method can be used to determine absolute configuration by relating the sign of the first Cotton effect of the host-amine complex to the handedness of the amine. Analysis of the primary circular dichroism optical data is by principal component analysis allows for differentiation of the analytes based on their idendity and handedness. A novel circular dichroism method for detecting chiral amines is discussed in chapter 3. The method uses a highly efficient derivatization method to convert the primary amine into a bidentate imine. Three equivalents of the imine are then assembled together by coordination to Fe(II). The proximity and chiral orientation of the imines leads to exciton coupled circular dichroism, which is of utility in the determination of absolute configuration. Additionally, there is a metal-to-ligand charge transfer band in the visible region that can be used to develop calibration curves, which allow for the determination of the enantiomeric excess of unknown samples with an absolute error of ±5%. Chapter 4 details another imine based circular dichroism method for chiral amines. The method uses a commercially available aldehyde, Fe(II), and circular dichroism spectrometry to sense chirality in amines. It is shown that the circular dichroism signals in the ultraviolet spectrum vary predictably with the handedness of the chiral amine, which has potential applications in the determination of absolute configuration. By developing calibraton curves, signals in the visible spectrum can be used to determine enantiomeric excess with an absolute error of ±6%. Analyzing the primary circular dichroism optical data with linear discriminant analysis allows for differentiation between amines based on their identity and handedness. Finally, chapter 5 illustrates the potential of using the thermodynamic parameters of partitioning between water and octanol as a predictive tool for estimating the contributions of hydrophobicity to host-guest binding events. This is done by showing a relationship between the thermodynamics of partitioning and thermodynamics of hydrophobic binding events for a series of guests and cyclodextrin. A plot of the thermodynamic parameters of binding of a variety of guests to cyclodextrin as a function of the thermodynamic parameters of partitioning between water and octanol shows a linear relationship for a series of alcohols. / text

The main goals of this research were to synthesize nitrogen oxide releasing diazeniumdiolates and their prodrugs and to evaluate their pharmacological effects. The different projects and their results are described below. i. Comparison of HNO and NO donating properties of cyclic amine diazeniumdiolates Diazeniumdiolates are an attractive class of donor compounds as they can be tuned to release NO or both NO and HNO depending upon the amine backbone. Isopropylamine (IPA/NO) and cyclohexylamine (CHA/NO) diazeniumdiolates are currently the only examples of primary amine based diazeniumdiolates. A series of structurally related cyclic amine based diazeniumdiolates were synthesized and characterized. An acetoxymethyl derivative was also synthesized to facilitate cellular uptake and to achieve higher HNO levels in cells. ii. Nitrogen oxide releasing diazeiumdiolate based adducts of N-des-methyl-tamoxifen Nitrogen oxide (NO/HNO) donating diazeniumdiolate adducts of N-desmethyltamoxifen (a key metabolite of the breast cancer drug tamoxifen) were synthesized. DEA/NO-AcOM, an NO donor was also synthesized to monitor the effect of NO on breast cancer cell survival. Derivatives of N-desmethyltamoxifen were found to be effective towards estrogen receptor positive (ER+) cells only. DEA/NO-AcOM was found to be cytotoxic towards estrogen-dependent and independent cell lines, in combination with tamoxifen, or by itself. iii. Synthesis and characterization of nitrogen oxide adducts with non-steroidal anti-inflammatory drugs (NSAIDs) Our group has shown HNO releasing diazeniumdiolate derivatized aspirin to be comparably effective in preventing gastric ulceration to NO-releasing diazeniumdiolate based aspirin analogues. Series of such NSAID adducts were further extended by synthesizing such derivatives of indomethacin and niflumic acid. NO/HNO releasing analogues of aspirin and indomethacin were cytotoxic towards two different breast cancer cell lines, irrespective of estrogen dependence.iv. Chlorambucil analogue of PABA/NOChlorambucil, an alkylating agent is used in leukemia treatment. Tumor cells resistant to alkylating agents often have increased glutathione levels and increased activity of glutathione-S-transferase (GST). PABA/NO is an NO donor with a promising anticancer profile. The chlorambucil analogue of PABA/NO was synthesized to utilize GST for releasing NO and to potentially overcome cellular resistance.