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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Análise de pseudopeptídeos e derivados do ácido tetrâmico como inibidores das calicreínas teciduais humanas 5 e 7

Souza, Bruno Eduardo Gomes January 2017 (has links)
Orientador: Prof. Dr. Luciano Puzer / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Biotecnociência, 2017. / As calicreinas 5 (KLK5) e 7 (KLK7) sao serino proteases que pertencem a um grupo de 15 calicrei.nas teciduais humanas (KLKs) encontradas em diversos tecidos do corpo. A KLK5 e encontrada principalmente no tecido mamario, sistema nervoso central, testiculos, prostata e traqueia, enquanto a KLK7 e encontrada no esofago, figado, rins e glandulas salivares. Alem disso, ambas as enzimas sao mais abundantemente expressas na pele humana, onde acredita-se que exercam importante papel no processo de descamacao epidermal, a partir da hidrolise de proteinas que compoem as estruturas de adesao intercelular dos corneodesmossomos. Estudos tambem demonstram, que a atividade dessas duas enzimas aparece aumentada em patologias relacionadas ao processo de descamacao da pele, como psoriase e dermatite atopica. Desta forma, o desenvolvimento de inibidores para KLK5 e KLK7 podera contribuir nao apenas para elucidar seus mecanismos fisiologicos e patologicos, mas como um arquetipo de novas drogas, visando ao desenvolvimento de novos procedimentos terapeuticos para patologias relacionadas ao processo de descamacao epidermal. Neste projeto, foram testados 17 pseudopeptideos e 10 compostos derivados do acido tetramico frente as calicrei.nas teciduais humanas 5 e 7, tripsina e quimotripsina. Dos 17 pseudopeptideos, oito compostos nao foram soluveis na fase de teste em meio aquoso e nove compostos foram soluveis em meio aquoso e puderam ser testados como inibidores das KLK 5 e KLK 7, sendo que quatro destes apresentaram inibicao utilizando concentracoes da ordem micromolar perante a KLK5. No entanto, apenas um composto obteve acao inibitoria frente a KLK7, porem com potencial inibitorio menor, comparado com resultados anteriores, relatados pelo nosso grupo de pesquisa. Os dez compostos aciltetramicos foram soluveis em tampao aquoso e apenas tres nao apresentaram atividade inibitoria contra as enzimas. Os resultados referentes as KLKs e tripsina foram significativos com uma acao inibitoria da ordem de micromolar. Os compostos derivados do acido tetramico nao inibiram a quimotripsina. Esses resultados abrem uma discussao sobre a especificidade da KLK7, que e classificada como uma enzima do tipo quimotripsina-like, no entanto, neste trabalho, apresentou um padrao de inibicao semelhante a tripsina. / The kallikreins 5 and 7 are serine proteases which belong to a group of fifteen human tissue kallikreins (KLKs) found in a diverse of body tissues. The KLK5 is mainly found on mammary tissue, central nervous system, testicles, prostate and trachea, while the KLK7 is found in the esophagus, liver, kidneys and salivary glands. Moreover, both enzymes are abundantly expressed on the human skin, and its believed that they have an important role on the epidermal desquamation process, from the hydrolysis of proteins that make up the corneodesmosomes intercellular adhesion structures. Recently it was shown that both kallikreins activity appears to be increased in diseases relates to the desquamation process, such as psoriasis and atopic dermatitis. Thus, the development of inhibitors for KLK5 and KLK7 would not only contribute to the elucidation of their physiological and pathological mechanisms, but also serve as an archetype for new drugs, aiming the development of new therapeutic procedures for diseases related to epidermal desquamation. In this project, 17 pseudo-peptides and 10 tetramic acid derived compounds were tested against the human tissue kallikreins 5 and 7, trypsin and chymotrypsin. From the 17 pseudo-peptides, nine were soluble in aqueous medium and could be tested; four of them showed inhibition in the micro molar range against the KLK5. Just one compound was effective against the KLK7, but with low inhibitory action. The 10 aciltetramic compounds were soluble in aqueous buffer, and only three of them did not show any inhibitory activity against the kallikreins. The results referring to the kallikreins and trypsin were significant, with an inhibitory action in the micro molar range. The compounds did not inhibit the chymotrypsin. These results open a discussion about the KLK7 specificity, which despite of being classified as a chymotrypsin-like enzyme, showed, in this work, an inhibition pattern similar to trypsin.
2

Synthèse de nouveaux composés chiraux à partir d'isosorbide et d'isomannide : applications en catalyse asymétrique / Synthesis of new chiral compounds from isosorbide and isomannide : applications in asymmetric catalysis

Ibrahim, Houssein 26 September 2011 (has links)
Ce travail de thèse porte sur la synthèse de nouveaux composés chiraux à partir de l’isosorbide et de l’isomannide en vue de leurs applications en catalyse asymétrique. Dans une première partie, de nouvelles monophosphines ont été synthétisées et appliquées en tant que ligands dans la réaction d'hydrogénation asymétrique d’oléfines. Des excès énantiomériques jusqu’à 96% ont été observés. Elles ont également été employées en tant que catalyseurs organiques dans les réactions de cyclisation [3 +2]. De bonnes activités catalytiques et des excès énantiomériques modestes sont obtenus. Dans une deuxième partie, une série de composés azotés chiraux a été synthétisée en 3 à 4 étapes avec de bons rendements globaux. Ils ont été testés en tant que ligands dans la réaction de réduction de cétones aromatiques par transfert d’hydrogène. Des excès énantiomériques jusqu’à 73% ont été obtenus. La réaction d’addition de phénylacétylène sur d’imines a également été étudiée. Les complexes formés se sont montrés actifs mais pas très énantiosélectifs. Ces composés azotés ont également été utilisés en tant que catalyseurs organiques dans la réaction d’addition de Michael de cétones aromatiques sur le nitrostyrène. Toutefois, ils n’ont permis de conduire qu’à de faibles énantiosélectivités. Dans une dernière partie, des composés de type thiourée ont été synthétisés en 5 étapes. Ces thiourées ont été appliquées en catalyse organique dans la réaction d’alkylation de type Friedel-Crafts entre différents substrats indoliques et nitrooléfines, et dans la réaction d’addition conjuguée des hydroxylamines sur des pyrazoles pour la synthèse de dérivés β-aminoacides. Ces catalyseurs se sont révélés actifs mais peu énantiosélectifs. / The Thesis deals with the synthesis of new chiral compounds derived from isosorbide and isomannide and their applications to asymmetric catalysis. The first part of this work consisted in perfecting the chemical and enantioselective hydrogenation conditions of olefins using chiral monophosphines as ligands (up to 96% ee). These phosphines were also used as organocatalysts for [3+2] cyclisation reactions showing good catalytic activity and moderate enantioselectivity. The second part turned to the synthesis of a series of chiral nitrogen compounds which were evaluated in the asymmetric transfer hydrogenation of aromatic ketones giving good enantioselectivity (up to 73% ee). The complexes formed with amine ligands were also applied to the addition reaction of phenylacetylene to imines. Good catalytic activity but low enantioselectivity were observed. These nitrogen compounds were also used as organocatalysts in the Michael addition reaction of aromatic ketones to the nitrostyrene. Again, low enantiomeric excess was obtained. The last part of this work consisted in preparing new chiral thiourea compounds which were applied as organocatalysts to the Friedel-Crafts alkylation reaction of different indoles with nitroolefines, and to the conjugate addition reaction of hydroxylamines to pyrazoles derivatives for the synthesis of β-amino acids. In two cases, these catalysts have proved active but not enantioselective.

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