No description available.

Made available in DSpace on 2014-06-11T19:24:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-02-17Bitstream added on 2014-06-13T20:52:19Z : No. of bitstreams: 1 horimoto_lk_me_botfca.pdf: 643530 bytes, checksum: a89cce04a174ddfc6169b6fc1e10b14b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Apesar dos amidos serem quimicamente iguais, a organização e funcionalidade desses polímeros dependem das propriedades físico-químicas de cada fonte botânica. Esses amidos podem sofrer diferentes modificações com a finalidade de aperfeiçoar certas características para aplicações industriais específicas. Dentre os amidos modificados, os catiônicos são largamente utilizados na fabricação de papel/papelão a fim de aumentar sua resistência física e mecânica. Neste trabalho, amidos de mandioca, batata doce e mandioquinha salsa foram cationizados com o reagente 3-cloro-2-hidroxipropil-trimetilamônio que em meio alcalino reage com o amido tornando-o carregado positivamente.As amostras foram submetidas a diferentes tempos de reação (0,5 a 24 horas) e relação molar de hidróxido de sódio/monômero. Os melhores parâmetros encontrados para as amostras foram de 6 horas de reação e relação molar de 2,0 NaOH/monômero, que resultaram em maiores DS (grau de substituição) e rendimento percentual, determinados a partir do teor de nitrogênio presente em cada amostra. Em seguida os amidos catiônicos com os melhores parâmetros foram submetidos a diferentes tratamentos após a derivatização: etanol a 25%, etanol a 50% e água a temperatura de 35°C, para avaliar a interferência dos sais residuários no grau de substituição das amostras derivatizadas. A seguir essas amostras de amidos catiônicos de mandioca, batata doce e mandioquinha salsa foram aplicadas em folhas de papel, onde testes físicos-mecânicos como resistências ao rasgo, arrebentamento, tração, permeância ao ar entre outros foram realizados com a finalidade de verificar a influência da adição de diferentes tipos de amido. / In spite of starches are chemically the same, the organization of biopolymers and the functionality of the starches depend on physical and chemical properties of each botanical source, which can undergo modifications with the purpose of improving certain characteristics for specific industrial applications. Among the modified starches, the cationic are widely used in the papermaking process in order to increase their physical and mechanical resistances. In this study, cassava, sweet potato and Peruvian carrot starches were cationized with 3-chloro-2-hydroxypropyltrimethylammonium choride reagent, that in a high pH reacts with starch become it positively loaded. The samples were submitted to different reaction time (0.5 to 24 hours) and the NaOH/monomer mole ratio. The best parameters found for the samples were of 6 hours of reaction time and 2.0 NaOH/monomer mole ratio, which resulted in larger degree of substitution (DS) and reaction efficiency (RE), determined by the 3 content of nitrogen present in each sample. Then the cationic starches with the best parameters were submitted to different treatments after derivatization: ethanol at 25%, ethanol at 50% and water at the temperature of 35°C, in order to evaluate the interference of the residual salts in the degree of substitution of the derivatized samples. In the sequence, these samples of cationic cassava, sweet potato and Peruvian carrot starches were applied in sheets of paper, where physical and mechanical tests such as air resistance, bursting strength, tensile strength, internal tearing resistance, among others, were performed with the purpose of verifying the influence of the addition of different types of starch.

De nouvelles architectures macromoléculaires ont été synthétisées à partir de lignine afin de développer des matériaux pour des applications dans le bâtiment. Trois voies différentes de modifications chimiques ont été retenues afin d’apporter de nouvelles propriétés à la lignine pour répondre à un cahier des charges précis. Dans un premier temps, des chaines de poly(caprolactone) ont été greffées sur la lignine par polymérisation par ouverture de cycle conférant ainsi à la lignine des propriétés particulières en fonction de la longueur des chaines de PCL greffées. La valorisation de la lignine pour la synthèse de polymères fonctionnels repose ainsi sur sa modification chimique. Notre démarche scientifique s’est par la suite axée sur la fonctionnalisation de la lignine afin d’en faire un synthon principal pour la synthèse de polyuréthanes (PU). Cette stratégie a été poursuivi avec l’addition d’acide oléique sur la lignine. Une réaction d’estérification a été mise au point par un procédé non solvanté en l’absence de catalyseur. Cet intermédiaire a été fonctionnalisé en vue d’obtenir un macropolyol réactif pour la synthèse de PU. Les propriétés des polymères ont été investiguées en modulant certains paramètres réactionnels. Les performances des matériaux obtenus ont montré l’intérêt de cette stratégie globale pour les applications finales visées. Enfin, dans une troisième et dernière approche, la réaction d’oxypropylation a été étudiée. Des chaines de polypropylène glycol ont été greffées sur la lignine aboutissant à l’obtention de quatre macropolyols différents avec des architectures macromoléculaires variées. Des PU ont été synthétisés à partir de ces macropolyols et les paramètres réactionnels ajustés en vue de moduler les propriétés finales des matériaux. Tous les PU réalisés ont démontré une séparation de phase attestant d’une organisation spécifique en segments souples/rigides et conférant des propriétés élastomères aux matériaux finaux. Cette étude a permis d’intégrer jusqu’à 89 % de matériaux biosourcés et renouvelables dans les polymères finaux et a montré le fort potentiel de la lignine pour l’élaboration de matériaux performants. / New macromolecular architectures have been performed by using lignin to develop new advanced materials for building applications. Three synthetic pathways have been carried out in order to impart specific properties to lignin-based materials. A Ring-Opening Polymerization has first been performed with ε-caprolactone to graft polymer chains onto lignin. Branching efficiency was confirmed by analysis and allows giving advanced properties to lignin materials. This first modification highlights the importance of lignin functionalization as building block for polymer synthesis. Then, we pursue the investigations by esterifying lignin with oleic acid by a solvent and catalyst-free method. Doubles bond were functionalized to obtain a lignin/fatty acid-based macropolyol that was then used for polyurethane synthesis (PU). Mechanical and thermal properties have been modulated by varying NCO:OH molar ratio and prepolymer molecular weight. Finally, oxypropylation was performed onto lignin by using various reaction parameters to obtain different macromolecular architectures for the resulting polyols. PUs have then been synthesized with the resulting macropolyols. The structure of macropolyols impacts greatly the thermal and mechanical properties of polymers, the influence of NCO:OH molar ratio was also studied.All of the PU reported in this work presented a micro-phase separation resulting in a specific organization (rigid/soft segments) into the polymer matrix. The lignin-based material revealed advanced thermal and mechanical properties with a high bio-based content up to 89%. This work allows emphasizing the potential of lignin as a starting material in the synthesis of sustainable material for building applications.

Orientador: Claudio Cabello / Banca: Claudio Angeli Sansígolo / Banca: José Luis Agapito Fernandes / Resumo: Apesar dos amidos serem quimicamente iguais, a organização e funcionalidade desses polímeros dependem das propriedades físico-químicas de cada fonte botânica. Esses amidos podem sofrer diferentes modificações com a finalidade de aperfeiçoar certas características para aplicações industriais específicas. Dentre os amidos modificados, os catiônicos são largamente utilizados na fabricação de papel/papelão a fim de aumentar sua resistência física e mecânica. Neste trabalho, amidos de mandioca, batata doce e mandioquinha salsa foram cationizados com o reagente 3-cloro-2-hidroxipropil-trimetilamônio que em meio alcalino reage com o amido tornando-o carregado positivamente.As amostras foram submetidas a diferentes tempos de reação (0,5 a 24 horas) e relação molar de hidróxido de sódio/monômero. Os melhores parâmetros encontrados para as amostras foram de 6 horas de reação e relação molar de 2,0 NaOH/monômero, que resultaram em maiores DS (grau de substituição) e rendimento percentual, determinados a partir do teor de nitrogênio presente em cada amostra. Em seguida os amidos catiônicos com os melhores parâmetros foram submetidos a diferentes tratamentos após a derivatização: etanol a 25%, etanol a 50% e água a temperatura de 35°C, para avaliar a interferência dos sais residuários no grau de substituição das amostras derivatizadas. A seguir essas amostras de amidos catiônicos de mandioca, batata doce e mandioquinha salsa foram aplicadas em folhas de papel, onde testes físicos-mecânicos como resistências ao rasgo, arrebentamento, tração, permeância ao ar entre outros foram realizados com a finalidade de verificar a influência da adição de diferentes tipos de amido. / Abstract: In spite of starches are chemically the same, the organization of biopolymers and the functionality of the starches depend on physical and chemical properties of each botanical source, which can undergo modifications with the purpose of improving certain characteristics for specific industrial applications. Among the modified starches, the cationic are widely used in the papermaking process in order to increase their physical and mechanical resistances. In this study, cassava, sweet potato and Peruvian carrot starches were cationized with 3-chloro-2-hydroxypropyltrimethylammonium choride reagent, that in a high pH reacts with starch become it positively loaded. The samples were submitted to different reaction time (0.5 to 24 hours) and the NaOH/monomer mole ratio. The best parameters found for the samples were of 6 hours of reaction time and 2.0 NaOH/monomer mole ratio, which resulted in larger degree of substitution (DS) and reaction efficiency (RE), determined by the 3 content of nitrogen present in each sample. Then the cationic starches with the best parameters were submitted to different treatments after derivatization: ethanol at 25%, ethanol at 50% and water at the temperature of 35°C, in order to evaluate the interference of the residual salts in the degree of substitution of the derivatized samples. In the sequence, these samples of cationic cassava, sweet potato and Peruvian carrot starches were applied in sheets of paper, where physical and mechanical tests such as air resistance, bursting strength, tensile strength, internal tearing resistance, among others, were performed with the purpose of verifying the influence of the addition of different types of starch. / Mestre

No description available.

Les travaux de recherche présentés ici ont pour objectif la synthèse de fongicides innovants de la manière la plus éco-compatible qu’il soit. Pour cela, plusieurs axes de réflexion ont été étudiés. Tout d’abord, la synthèse d’un intermédiaire de fongicides bien connu, l’o-crésol1, a été réalisée à partir d’un substrat naturel, le salicylaldéhyde2. Les conditions expérimentales ont été éco-conçues afin de correspondre au mieux aux exigences de la chimie verte. Des solvants et des réactifs classés verts ont été utilisés, comme l’éthanol, l’eau et l’acide acétique3 par exemple, ainsi que des techniques alternatives comme l’activation par micro-ondes (Schéma 1). Dans un second temps, des synthèses éco-compatibles de nouveaux fongicides ont été réalisées. Le salicylaldéhyde, substrat naturel de référence, a été mis à réagir avec différents alcools afin de réaliser des réactions d’éthérifications réductrices. Les molécules obtenues sont composées d’une partie phénolique portant un groupement alcoxyle en position 2. Ce groupement alcoxyle se compose d’une longueur de chaîne variable ayant une influence sur les propriétés fongicides des produits synthétisés (Schéma 1). Troisièmement, des réactions d’homo- et d’hétéro-couplages pinacoliques ont été réalisées entre divers aldéhydes, aromatiques et aliphatiques, afin d’obtenir des diols vicinaux, appelés pinacols, symétriques ou non (Schéma 1). Dernièrement, les propriétés fongicides et anti-oxydantes de toutes les molécules obtenues de manière stable, référencées ou non, ainsi que les substrats de départ, ont été testés. Les tests microbiologiques ont été réalisés sur une gamme de diverses souches fongiques. / The purpose of this research is to synthesize innovative fungicides by the most ecocompatible way. Several hypotheses have been investigated. First, an extensively studied molecule, intermediate of fungicides, o-cresol1, has been achieved from a natural substrate, salicylaldehyde2. The experimental conditions have been eco-designed in the aim to best match green chemistry requirements. Green solvents and reactants have been used, as ethanol, water and acetic acid3 for example, as well as alternative technologies like microwaves activation (Schema 1). Secondly, novel fungicides green syntheses have been carried out. Salicylaldehyde, a natural substrate model, reacted with various alcohols in the aim to perform reductive etherification reactions. In this way, products were composed of phenolic part with an alkoxyl group at the 2nd position. These alcoxyl groups have various chain lengths, playing a key role in fungicidal ability (Schema 1). Then, homo and hetero pinacol coupling reactions have been achieved with various aromatic or aliphatic aldehydes to obtain symmetrical and asymmetrical vicinal diols, called pinacols (Schema 1). At last, fungidal and antioxidant properties of all stable obtained molecules, referenced or not, as well as starting materials, have been evaluated. Microbiological studies have been carried out with various fungal strains.

In this thesis, carbohydrate mimicry is investigated through the syntheses of carbohydrate analogues and evaluation of their inhibitory effects on carbohydrate-processing enzymes. Galactofuranosides are interesting structures because they are common motifs in pathogenic microorganisms but not found in mammals. M.tuberculosis, responsible for the disease tuberculosis, has a cell wall containing a repeating unit of alternating (1→5)- and (1→6)-linked β-D-galactofuranosyl residues. Synthetic inhibitors of the enzymes involved in the biosynthesis of the cell wall could find great therapeutic use. The first part of this thesis describes the first synthesis of the hydrolytically stable carbasugar analogue of galactofuranose, 4a-carba-β-D-Galf, and the synthetic work of synthesising β-linked pseudodisaccharides containing carba-Galf, which were tested for glycosyltransferease inhibitory activity. The pseudodisaccharide carba-Galf-(β1→5)-carba-Galf was found to be a moderate inhibitor of the glycosyltransferase GlfT2 of M.tuberculosis. The thesis also describes how a general method towards biologically relevant α-linked carba-Galf ethers was developed. The final part of this thesis is focussed on the formation of nitrogen-linked monosaccharides without the participation of the anomeric centre. Such a mode of coupling is called tail-to-tail neodisaccharide formation. The couplings of carbohydrate derivatives via the Mitsunobu reaction are successfully reported herein. The method describes the key introduction of an allylic alcohol in the electrophile and the subsequent functionalisation of the alkene to obtain the neodisaccharide. Two synthesised neodisaccharides presented in this thesis have been sent to be tested for glycosidase inhibitory activity. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript. Paper 5: Manuscript. Paper 6: Manuscript.

Ces dernières années, la notion de Développement Durable a bouleversé la recherche académique etindustrielle dans le domaine de la chimie. L’utilisation de matières premières issues des ressources renouvelables en constitue l’un des aspects les plus marquants. De même, le développement de procédés originaux, qui s’appuient sur des systèmes catalytiques recyclables, des transformations chimiques innovantes et de nouveaux solvants plus respectueux de l’environnement font l’objet d’un intérêt croissant, en raison des gains environnementaux et économiques. Les travaux de recherche décrits dans cette thèse s’inscrivent dans ce contexte et présentent la mise au point de nouvelles voies d’accès aux éthers de glycérol, des molécules à haute valeur ajoutée. Plusieurs procédés originaux ont été développés en utilisant le glycérol comme substrat biosourcé issu de l’industrie oléo-chimique. Ainsi, l’alkylation réductrice d’acides carboxyliques avec le glycérol en présence de palladium sur charbon et d’une résine acide a permis de préparer une variété de 1-Oalkyléthersde glycérol. Une procédure alternative a été développée à partir des huiles végétales et des esters méthyliques, par transestérification puis réduction de l’ester intermédiaire sous hydrogénation catalytique. Ensuite, un procédé d’alkylation déshydrogénante de dérivés de la cyclohexanone avec le glycérol a donné un nouvel accès aux 1-O-aryléthers de glycérol et a été étendu aux éthers et aux amines aromatiques. Enfin, de nouveaux solvants aprotiques dérivés du glycérol ont été synthétisés par une catalyse de transfert de phase. En particulier, la toxicité du 1,2,3-triméthoxypropane ainsi que son utilisation dans des transformations chimiques comme nouveau solvant ont été évaluées. / In recent years, sustainable development brought unprecedented changes in industrial and academic researches. The use of raw materials from renewable resources is one of the most outstanding aspects of these changes. The development of original processes, with recyclable catalytic systems, new chemical transformations as well as new solvents with a lower environmental impact are of growing interest, because of environmental and economical profits. The research work described in this thesisis focused on the development of new accesses to glyceryl ethers as high value added coumpounds.Thus, several processes were developed by using glycerol as accessible and bio-based starting material from the oleochemical industry. First, we found a benign and eco-friendly process for the synthesis of1-O-alkyl glyceryl ethers by catalytic reductive alkylation of carboxylic acids with a recyclable catalytic system associating palladium on carbon and an acid ion exchange resin. A second two steps procedure was also developed when starting from a vegetable oil or a methyl ester, which was transesterified to the corresponding monoglyceride followed by its reduction by catalytic hydrogenation. We report also a straight forward and palladium catalyzed dehydrogenative alkylation of cyclohexanone derivatives with alcohols, including glycerol, and amines in order to prepare avariety or aryl ethers and aryl amines. Finally, we prepared new aprotic and glycerol-based solvents bya solvent-free phase-transfer catalysis. In particular, the toxicity of 1,2,3-trimethoxypropane and its utilization as alternative solvent in chemical transformations was evaluated.

No description available.

L’accès par voie chimique à des oligosaccharides nécessite souvent le recours à de nombreuses étapes de protection-déprotection. Au cours de ce projet de thèse, une méthodologie pour la protection régiosélective et orthogonale des fonctions alcool de disaccharides dérivant de la biomasse a tout d’abord été développée. Les glycopyranosides protégés ont été préparés par catalyse tandem au FeCl3∙6H2O en réalisant dans le même pot des réactions d’acétalation, d’éthérification réductrice, d’acétylation et/ou d’ouverture réductrice régiosélective d’acétals. Dans un second temps, une stratégie de synthèse flexible, rapide et performante pour accéder à des sulfoglycolipides diacylés et tétraacylés comportant un cœur tréhalose a été mise au point. Ces molécules sont produites par Mycobacterium tuberculosis, l’agent pathogène responsable de la tuberculose, et les sulfoglycolipides diacylés pourraient permettre l’élaboration d’un nouveau vaccin contre cette maladie. Des sulfoglycolipides diacylés et tétraacylés comportant des chaînes monométhylées chirales ont été obtenus. Les précurseurs des acides gras chiraux utilisés au cours de la synthèse ont été analysés par spectroscopie RMN du deutérium en abondance naturelle dans des cristaux liquides chiraux. / The synthesis of oligosaccharides often requires long sequences of protection-deprotection steps. For a rapid access to suitably protected glycopyranosides, we have developed a one-pot regioselective protection strategy based on FeCl3∙6H2O-tandem catalyzed reactions (acetalation, acetylation, reductive etherification, regioselective ring opening of acetal). This procedure was applied to persilylated disaccharides derived from biomass. This methodology allowed the development of a fast, efficient and flexible access to diacylated and tetraacylated sulfoglycolipids based on a trehalose core. These molecules are found in the cell wall of Mycobacterium tuberculosis and the diacylated sulfoglycolipids appear to be promising candidates for the development of a new tuberculosis vaccine. Synthetics diacylated and tetraacylated sulfoglycolipids bearing chiral monomethylated fatty chains were produced. The chiral fatty-acid precursors, used in the procedure, were synthetized and analyzed by NMR spectroscopy of natural abundance deuterium in chiral liquid crystals.