Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Inhibition of fatty acid amide hydrolase (FAAH) or monoacylglycerol lipase (MAGL), the chief degradative enzymes of N-arachidonoyl ethanolamine (anandamide; AEA) and 2-arachidonoylglycerol (2-AG), respectively, elicits no or partial substitution for Δ9-tetrahydrocannabinol (THC) in drug discrimination procedures. However, combined inhibition of both enzymes fully substitutes for THC, as well as produces a full constellation of cannabimimetic effects. Because no published report to date have investigated whether an inhibitor of endocannabinoid hydrolysis will serve as a discriminative stimulus, the purpose of this doctoral dissertation was to investigate whether C57BL/6J mice would learn to discriminate SA-57 (4-[2-(4-Chlorophenyl)ethyl]-1-piperidinecarboxylic acid 2-(methylamino)-2-oxoethyl ester), a dual inhibitor of FAAH and MAGL, from vehicle in the drug discrimination paradigm. Also, we sought to determine whether inhibiting both enzymes, or inhibiting one enzyme was necessary to generate the SA-57 discriminative stimulus. Initial experiments showed that SA-57 fully substituted for either CP 55,940 ((-)-cis-3-[2-Hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4-(3-hydroxypropyl)cyclohexanol), a high efficacy CB1 receptor agonist in C57BL/6J, mice or AEA in FAAH (-/-) mice. The majority (i.e., 23 of 24) of subjects achieved criteria of discriminating SA-57 (10 mg/kg) from vehicle within 40 sessions, with full generalization occurring 1-2 h post injection. CP 55,940, the dual FAAH-MAGL inhibitor JZL195 (4-nitrophenyl 4-(3-phenoxybenzyl)piperazine-1-carboxylate), the MAGL inhibitors MJN110 (2,5-dioxopyrrolidin-1-yl 4-(bis(4-chlorophenyl)methyl)piperazine-1-carboxylate) and JZL184 (4-[Bis(1,3-benzodioxol-5-yl)hydroxymethyl]-1-piperidinecarboxylic acid 4-nitrophenyl ester) fully substituted for SA-57. Although, the FAAH inhibitors PF-3845 and URB597 did not substitute for SA-57, PF3845 produced a two-fold leftward shift in the MJN110 substitution dose-response curve. In addition, the CB1 receptor antagonist rimonabant blocked the generalization of SA-57 as well as substitution of CP 55,940, JZL195, MJN110, JZL184 for the SA-57 discriminative stimulus. These findings taken together indicate that the inhibition of endocannabinoid-regulating enzymes serve as breaks to prevent overstimulation of CB1 receptors, and MAGL inhibition is the major driving force for generating the SA-57 discriminative stimulus.

Cross-coupling reactions, where a transition metal catalyst facilitates the formation of a new carbon-carbon or carbon-heteroatom bond between two coupling partners, has become one of the most widely used, reliable, and robust family of transformations for the construction of molecules. The Nobel Prize was awarded to pioneers in this field who primarily used aryl iodides, bromides, and triflates as electrophilic coupling partners. The expansion of the reaction scope to non-traditional electrophiles is an ongoing challenge to enable an even greater number of useful products to be made from simple starting materials. The major goal of this thesis research is to improve and expand upon this field by using esters as electrophiles via the activation of the strong C(acyl)−O bond. Esters are particularly robust in comparison to other carboxylic acid derivatives used in cross-coupling reactions. Success on the activation of such inert functional group using catalysis has both fundamental and practical value. By discovering new reaction modes of this abundant functional group, synthetic routes to access novel or industrially important molecules can be improved. Chapter 1 of this thesis describes a literature overview of what has been accomplished in the field of cross coupling reactions using carboxylic acid derivatives as electrophilic coupling partners. Chapter 2 discloses the first palladium Suzuki-Miyaura couplings of phenyl esters to produce ketones. The method is efficient and robust, giving good yields of useful products. The reaction is proposed to proceed via an oxidative addition to the strong C(acyl)−O bond of the ester. In contrast to previous efforts in this field that use traditional catalysts such as Pd(PPh3)4, the developed reaction requires use of an electron-rich, bulky N-heterocyclic carbene ligand, which facilitates the strong bond activation. Furthermore, a palladium-catalyzed cross-coupling between aryl esters and anilines is reported, enabling access to diverse amides. The reaction takes place via a similar activation of the C−O bond by oxidative addition with a Pd−NHC complex, which enables the use of relatively non-nucleophilic anilines that otherwise require stoichiometric activation with strong bases to react. Chapter 3 discloses a nickel-catalyzed amide bond formation using unactivated and abundant esters. In this transformation, an accessible nickel catalyst can facilitate the activation of diverse aliphatic and aromatic esters to enable direct amide bond formation with amines as nucleophiles. No stoichiometric base, acid, or other activating agent is needed, providing exceptional functional group tolerance and producing only methanol as a by-product. This reaction is of both fundamental and practical importance because it is the first to demonstrate that simple conditions can enable Ni to cleave the C–O bond of an ester to make an oxidative addition product, which can be subsequently coupled with amines. This discovery contrasts industrially-common and wasteful methods that still require stoichiometric activating agents or multistep synthesis. Chapter 4 describes the evaluation of different types of cross-coupling reactions using methyl esters as electrophilic coupling partner. A high-throughput screening technique has been applied to this project. A combination between specific ligands, known by their efficiency to activate strong C−O bonds, and literature-based conditions has been designed for the chosen transformations. Using this strategy, two promising hits have been obtained using the same NHC ligand: a decarbonylative Suzuki-Miyaura and a decarbonylative borylation reaction.

Neste trabalho foi estudado o eletrólito sólido polimérico obtido através da plastificação do amido rico em amilopectina com glicerol em porcentagem de 30% em ralação a massa do amido utilizado, e contendo perclorato de litio (LiClO4), com uma razão [0]/[Li] = 10 (AGL). Com o objetivo de estudar a influência da umidade relativa nas propriedades de transporte iônico do eletrólito, foi utilizada a técnica de Ressonância Magnética Nuclear RMN. Neste trabalho, também, foram utilizadas outras técnicas de caracterização como: DSC, TGA e condutividade A.C. No estudo de RMN, foram realizadas medidas da forma de linha e da taxa de relaxação spin-rede do 1H e do 7Li em função da temperatura, a fim, de estudar a mobilidade do próton e do íon lítio no complexo polimérico. Os resultados desacoplamento do 7Li {1H} medidos na temperatura de 183K mostraram que 80% da largura de linha foi atribuída a interação heteronuclear Li-H. Os resultados da relaxação mostraram um aumento na mobilidade do complexo polimérico e do íon lítio com o aumento da hidratação do eletrólito. Os valores para a energia de ativação são da ordem de 0.20eV para o próton e 0.23eV para o lítio, consistente com os valores encontrados em outros eletrólitos sólidos poliméricos (0.2 - 0.3eV) / In this work we report the study of solid polymer electrolyte obtained from amylopectin rich starch plasticized with 30% in mass of glycerol and lithium perchlorate (LiClO4) with a reason [0]/[Li] = 10. With the objective to study the influence of the relative humidity in the properties of ionic transport of the electrolyte, the technique of Nuclear Magnetic Resonance - NMR was used. The samples were also characterized by DSC, TGA and A.C. conductivity. The mobility of protons and lithium ion were study through the temperature dependence of 1H and 7Li NMR lineshape and spin-lattice relaxation times. The 7Li {1H} decoupling results measured in the temperature of 183K, shows that 80% of the width of line was attributed to Li-H heteronuclear interaction. The relaxation results showed an increase of mobility of proton and lithium ion in the polymer complex with the increase of the relative humidity of the electrolyte. Activation energy of the arder of 0.20eV for the proton and 0.23eV for lithium were obtained from NMR measurements, consistent with the values found in other solid polymer electrolyte (0,2 - 0.3eV)

Multiple sclerosis (MS) is a demyelinating neurodegenerative disease that typically has a relapsing-remitting pattern of progression superimposed on a gradual worsening of disease symptoms. Experimental autoimmune encephalomyelitis (EAE) is a model of MS where animals develop relapses, demyelination and accumulate neurological deficits. Studies using the EAE model have provided evidence that cannabinoids are beneficial in reducing disease symptoms and may impact long term neurodegeneration, but side-effects of exogenous cannabinoid receptor agonists may limit their potential as therapeutic agents for MS. Targeting enzymes involved in degradation of endocannabinoids such as the anandamide-degrading enzyme fatty acid amide hydrolase (FAAH) may be an attractive alternative strategy. Using experimental allergic encephalomyelitis (EAE) as a mouse model of MS, two complementary approaches were used to assess FAAH as a potential therapeutic target. The FAAH deficient (ABH.FAAH-/-) developed similar paralytic relapsing disease of similar severity of disease compared to the wild-type, but showed a poorer recovery following the acute phase. However, following a relapsing-remitting disease course, the FAAH deficient mice showed a substantial improvement in clinical score, improved motor control, and lost less neurofilament compared to wild-type mice. These findings indicate that fatty acid amides may be neuroprotective in EAE. Secondly, a selective FAAH inhibitor (PF-3845; 10 mg/kg) was used to treat mice during the relapse phase of the disease course. Treatment with PF-3845 caused an elevation of anandamide in the CNS. This treatment resulted in a small reduction in neurofilament loss, but no reduction in clinical score or improvement in motor control was observed compared to the vehicle treated group. To investigate at a cellular level how FAAH might affect disease progression in the EAE model, immunohistochemistry was used to analyse FAAH expression in the CNS. Employing novel antibodies to FAAH in combination with neuronal and glial cell markers, it was found that, in addition to previously reported neuronal expression of FAAH, FAAH is highly expressed 3 in oligodendrocytes, but not in other glial cell types. Thus, genetic deletion or pharmacological inhibition of FAAH may affect both neuronal activity and oligodendroglial function (e.g. myelination). The role of FAAH in oligodendrocytes was investigated in vitro. An oligodendrocyte precursor cell (OPC) monoculture was used to monitor differentiation, and a co-culture comprising neurons and OPCs was used to monitor myelination. During the differentiation of OPCs, FAAH expression was detected in the entire oligodendroglia lineage, but with high expression only in mature myelin basic protein (MBP) expressing cells. Treatment with the FAAH inhibitor PF-3845 (0.1 μM to 1 μM) increased differentiation of OPCs into mature oligodendrocytes. However, the same treatment of co-cultures had no effect on the myelination of neurites. In conclusion, this study has: i) obtained evidence that genetic deletion of FAAH is neuroprotective in a mouse model of MS and ii) provided new insights on FAAH expression in the CNS. Further investigation of FAAH, in particular its role(s) in oligodendrocytes, will be required to fully unlock the therapeutic potential of FAAH inhibition in the treatment of MS.

N-heterocyclic carbenes (NHCs) can be used as ligands for organometallics complexes, which can then facilitate numerous catalytic applications, such as, C-H activation, small molecule activation and numerous materials applications. The use of anionically-tethered NHCs for usage with electropositive metals has been pioneered by the Arnold group within the last decade. This thesis describes the synthesis of both aryloxide- and amide-tethered NHC organometallic complexes of s-, p-, d- and f-block metals to provide a platform for small molecule activation. Once synthesised, the reactivity of some of these complexes were tested by reaction with CO2 with the aim of turning a molecule considered a harmful (environmentally), waste product into value added products, potentially providing an alternative fuel source. Chapter One introduces the use of anionically-tethered NHCs for use in a number of organometallic complexes as well as their current potential as catalysts for a number of important small molecules. This chapter focuses upon the differences between complexes tethered with anionic O, N, P, S elements, f-element NHC complexes and the use of d-block NHC complexes for catalysis. Chapter Two contains the synthesis and characterisation of a number of aryloxy-tethered NHC p-, d- and f-block organometallic complexes using the ligand H2(LArO R)2. The synthesis of SnII complexes including the synthesis of new ‘normal’ ‘abnormal’ complexes given enough steric bulk around the Sn centre due to the lone pair present in Sn complexes, preventing one of the ligands binding through the classical carbene position and therefore binding through the backbone C4 carbon. The synthesis of MII (Zn, Co and Fe) complexes to compare the solid-state structure and binding mode of the carbenes. The synthesis and characterisation of MIII (Ce and Eu) complexes to assess the solid-state structure and binding modes within f-bock complexes. Chapter Three investigates the reactivity of the MII complexes (Sn, Zn, and Fe) with CO2. Successful reactions were characterised using NMR and further treated with alkynes to target catalytic reactions. Chapter Four contains reactions to target a number of amide-tethered bis (NHC) s-, p-, d- and f-block organometallic complexes using the proligand, H4(LN Mes)Cl3. Deprotonation studies undertaken with a number of bases to give the MI (Li and K) salts and MII (Mg) salts and proved to be unsuccessful upon isolation. Reactions to synthesise the p-, d- and f-block complexes were then undertaken using in situ free carbene production as well as the attempted isolation of the free carbene, both of which also proved unsuccessful. Chapter Five provides an overall conclusion to the work presented in Chapters Two, Three and Four within this thesis. Chapter Six gives the experimental and characterising data for the complexes and reactions.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-08-29T14:02:13Z No. of bitstreams: 1 2009 - Breno Almeida Soares.pdf: 7105040 bytes, checksum: 3b6aebf34151816545510b0506ed3412 (MD5) / Made available in DSpace on 2017-08-29T14:02:13Z (GMT). No. of bitstreams: 1 2009 - Breno Almeida Soares.pdf: 7105040 bytes, checksum: 3b6aebf34151816545510b0506ed3412 (MD5) Previous issue date: 2009-09-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior, CAPES, Brasil. / This work is part of a research project which investigates the utilization of abundant and accessible natural products in the synthesis of new molecules with potential activity against Chagas? disease. Recent studies carried out in our laboratory showed activity against Trypanosoma cruzi for piperine, a major component of Piper nigrum and for a series of its derivatives and analogues. Using bioisosterism as a strategy for molecular modification, we describe here the design, synthesis and antiparasitic evaluation of class of derivatives of 1,2,4-oxadiazole. The key step of the synthetic strategy used involved the SNAC reaction of the benzamidoxima with acid chlorides followed by cyclization, which allowed the preparation of eight new 1,2,4-oxadiazole The evaluation of the toxic activity of these new derivatives against epimastigote form of T. cruzi confirmed the bioisosteric relationship between the natural amide and the new products prepared, showing the oxadiazole 55 direct derived from piperine, as the most active compound in the series. / Este trabalho se insere numa linha de pesquisa que visa a utiliza??o de produtos naturais abundantes e access?veis na s?ntese de novas mol?culas com potencial atividade anti-chag?sica. Estudos recentes em nosso laborat?rio demonstraram a atividade antiparasit?ria da piperina e de uma s?rie de derivados e an?logos sobre o Trypanosoma cruzi, agente etiol?gico da doen?a de Chagas. Utilizando o bioisosterismo como estrat?gia de modifica??o molecular, descrevemos aqui o planejamento, a s?ntese e a avalia??o antiparasit?ria de derivados da classe dos 1,2,4-oxadiaz?is. A etapa-chave da estrat?gia sint?tica utilizada envolveu a rea??o de SNAC da benzamidoxima com cloretos de ?cidos, seguida de cicliza??o, que permitiu a prepara??o de oito novos 1,2,4- oxadiaz?is. A avalia??o da atividade t?xica destes novos derivados contra a forma epimastigota do T. cruzi confirmou a rela??o bioisost?rica entre a amida natural e os novos derivados preparados, evidenciando o oxadiazol 55 derivado direto da piperina, como o composto mais ativo da s?rie.

N-acylethanolamines (NAEs) are derived from a minor membrane lipid constituent N-acylphosphatidylethanolamine and are hydrolyzed by fatty acid amide hydrolases (FAAH) into free fatty acid (FFA) and ethanolamine in both plants and animals. In Arabidopsis, NAE plays an important physiological role in growth/development and response to stress. Although NAEs are reported in tomato, their metabolic pathway remains undiscovered. It is hypothesized that there is a functional FAAH in tomato that hydrolyzes NAEs. To this extent, a putative gene that likely encodes for putative SlFAAH1 protein was identified, cloned, and heterologously expressed. Amidase activity was tested using radiolabeled NAE substrates. Furthermore, expression of putative SlFAAH1 transcripts and protein activity was quantified at different developmental stages to demonstrate endogenous amidase activity in tomato seedlings. In future, molecular and biochemical characterization of tomato FAAH will further test the conserved nature of NAE metabolic pathway in plants.

Dans ce manuscrit sont décrites de nouvelles procédures pour la synthèse stéréosélective d’un composé d’intérêt pharmacologique ainsi que leurs implémentations pour la production en continu. Plusieurs procédures de modification de catalyseurs hétérogènes commerciaux ont été développées et ont permis d’augmenter significativement la diastéréosélectivité de la réaction d’hydrogénation d’un intermédiaire de synthèse. Une voie de synthèse alternative par dérivatisation a également été développée, permettant d’atteindre une diastéréosélectivité pus élevée. De plus, des réacteurs modulaires dédiés à la réalisation de réactions triphasiques gas/liquide/solide sous haute pression ont été conçus. Un prototype a été fabriqué et a pu être utilisé pour les procédures d’hydrogénation développées. Enfin, un intermédiaire de synthèse a été préparé sans solvant ni additifs et avec une grande productivité en utilisant un microréacteur. / In this thesis, we present new procedures for the highly stereoselective synthesis of an active pharmaceutical ingredient and initiate their implementation in continuous flow for production. We developed several procedures for the highly diastereoselective hydrogenation reactions using chemically modified commercial heterogeneous catalysts. In addition, a three step reaction pathway through hydrolysis, highly diastereoselective hydrogenation reaction and conversion back to primary amide was developed to prepare. Modular high pressure continuous reactors have been designed and a prototype has been manufactured to perform the gas/liquid/solid triphasic hydrogenation reactions. Finally, we prepared a synthesis intermediate without solvents nor additives in continuous flow using a home-made micro-reactor, dramatically increasing the productivity of the process.

The pawhuskins and schweinfurthins are two classes of stilbene natural product compounds that exhibit interesting biological activity, and because of this they have been studied extensively in our lab through synthetic means. The pawhuskins are a class of small molecule non-nitrogenous opioid receptor modulators that differ significantly in structure from the classical opioid receptor ligands. Some of the natural schweinfurnthins show strong and differential antiproliferative behavior towards a variety of human cancer cell lines. Prior to this research, a significant structure-activity relationship study conducted in our lab has produced a large library of analogues of both classes of compounds. The most potent of theses analogues have served as lead compounds in this study where the stilbene motif present in both classes was substituted with either an amide or triazole linkage. For the new pawhuskin analogues, three of the amide isomers and a triazole isomer synthesized showed antagonist activity for the opioid growth factor (OGF)/opioid growth factor receptor (OGFR) axis which is involved in cellular and organ growth control. This cellular signaling mechanism is targeted by “low-dose” naltrexone therapy which is being tested clinically for multiple sclerosis, Crohn’s disease, cancer, and wound healing disorders. The compounds described here are the first selective small molecule ligands for the OGF/OGFR system and will serve as important leads and probes for further study. For the new schweinfurthins analogues, all compounds synthesized retained antiproliferative activity against similar cancer cell lines to that of the natural compounds. The new amide analogues were produced in pairs only differing in the orientation of the amide linkage replacement for the stilbene motif. Signifigantly greater activity was seen for one orientation of the amide over the other. The synthetic efforts towards all of these analogues will be described herein along with their intriguing biological properties.