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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

Synthèse et fonctionnalisation de 2-thiohydantoïnes : interaction et inhibition des nucléosides monophosphate kinases / Synthesis and functionalization of 2-thiohydantoins : interaction and inhibition of nucleoside monophosphate kinases

Gosling, Sandrine 14 November 2011 (has links)
La découverte de nouvelles substances thérapeutiques nécessite la synthèse de série de molécules soumises au criblage biologique sur une cible donnée. Ce projet de recherche a pour objectif de développer des inhibiteurs de nucléosides monophosphate kinases (NMPK) en se basant sur le concept de chimie dynamique combinatoire in situ. La synthèse de ces molécules a nécessité l’association via des fonctions réactives d’un analogue d’accepteur de phosphate et d’un mime d’ATP donneur de phosphate. La mise au point de ce dernier a fait l’objet de ce travail de thèse et a été orientée vers la pharmacomodulation d’un hétérocycle azoté et soufré: la 2-thiohydantoïne. La synthèse de ce composé a été réalisée par la méthode de Schlack-Kumpf et par celle d’Edman provenant de techniques d’analyses peptidiques. Ces deux voies ont été exploitées pour étudier la réactivité et la fonctionnalisation sélective de cet hétérocycle notamment par des couplages de type Suzuki. La réaction de Vilsmeier-Haack-Arnold a par la suite constitué l’étape clé permettant de transformer un cycle 2-thiohydantoïne en un cycle de type imidazole qui a pu être fonctionnalisé en diverses positions. La synthèse de dérivés 2-thiohydantoïne et imidazole diversement substitués par des groupements utiles, au couplage in situ avec les analogues d’accepteur de phosphate ainsi qu’à l’affinité enzymatique a permis l’accès à une bibliothèque de molécules. Des tests biologiques ont permis d’évaluer leur affinité vis-à-vis de plusieurs NMPK ainsi que leur cytotoxicité sur cellules cancéreuses ; cet ensemble de résultats permettant de trouver les déterminants nécessaires à l’activité biologique. / New therapeutical compounds determination requires the formation of a library of molecules and their screening on specific biological targets. The aim of this project was to design new inhibitors targeting nucléoside monophosphate kinases (NMPK) based on in situ dynamic combinatorial chemistry. These molecules were synthesized by ligation between analogues of phosphate acceptors and donors on which reactive functions were introduced. The topic of this PhD was to develop the ATP mimetics using chemical transformation and pharmacomodulation of a small heterocycle: 2-thiohydantoin. Its synthesis was achieved using the Schlack-Kumpf and the Edman methods initially develop for peptidic analysis. These two pathways have been explored in order to study the reactivities and the selective functionalizations of the heterocycle allowing for example Suzuki cross coupling reactions. Furthermore we used the Vilsmeier-Haack-Arnold reaction as a key step to the formation of a highly substituted imidazole ring directly from a 2-thiohydantoin. The synthesis of 2-thiohydantoin and imidazole derivatives, on which reactive groups for the in situ coupling reactions and the enzymatic affinity have been introduced, leads to a library of molecules. Their affinity toward to ATP donor site of NMPK and their toxicity on cancer cells were evaluated by biological tests.
2

Desenvolvimento e caracterização de nanopós obtidos por complexação de lantanídeos com tio-hidantoína e 1,10’ fenantrolina. / Development and characterization powders obtained by lanthanide complexation with hydantoin and 1,10’- phenanthroline.

PINTO FILHO, Francisco. 13 June 2018 (has links)
Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-06-13T19:56:21Z No. of bitstreams: 1 FRANCISCO PINTO FILHO – TESE (PPGEP) 2016.pdf: 2405186 bytes, checksum: d7b5b1d68600f138fc5134159b39d6fc (MD5) / Made available in DSpace on 2018-06-13T19:56:21Z (GMT). No. of bitstreams: 1 FRANCISCO PINTO FILHO – TESE (PPGEP) 2016.pdf: 2405186 bytes, checksum: d7b5b1d68600f138fc5134159b39d6fc (MD5) Previous issue date: 2016-08-29 / Capes / A busca por inovações tecnológicas nos últimos anos cada vez mais se intensifica. Neste contexto, dois importantes grupos, os lantanídeos e as hidantoínas se destacam com importantes contribuições em diversas áreas de pesquisas apresentando vasto campo de aplicações. Nesses termos, esta pesquisa teve como objetivo sintetizar e caracterizar nanocomplexos dos íons lantanídicos: Eu +3, Er+3 e Nd+3 com 5-(4-metilfenil)-3-fenil-2-tioxo-imidazolidin-4-ona (HPA) e um segundo ligante, 1,10-fenatrolina (Phen), almejando obter complexos com propriedades biológicas. Partindo da reação entre os cloretos dos respectivos lantanídeos com os ligantes orgânicos, sob refluxo de aproximadamente 8 horas e temperatura de 60°C, foram obtidos os complexos de európio, érbio e neodímio. Os nanocomplexos em pó foram caracterizados utilizando técnicas de análises espectroscópicas, térmicas e estrutural. Os complexos de íons lantanídicos apresentaram resultados da análise elementar conforme a estequiometria proposta (1:3:1). A coordenação dos ligantes com os íons lantanídicos ocorreu através dos átomos de oxi gênio e enxofre da estrutura do 5-(4-metilfenil)-3-fenil-2-tioxo-imidazolidin-4-ona (HPA) e dos átomos de nitrogênio (C=N) da 1,10’- fenantrolina, que podem ser observados nos espectros de infravermelho, através dos deslocamentos dessas bandas presentes nos ligantes livres e coordenados. Os espectros UV-Vis apresentaram discretos deslocamentos e mudanças nas intensidades das bandas de absorção dos complexos em relação ao ligante HPA. As curvas TG/DTG do ligante HPA apresentou 3 etapas de decomposição, enquanto, que os complexos apresentaram 4 etapas. O nanocomplexo de Eu+3 apresentou menor estabilidade térmica, o que possibilita o uso destes pós como fármacos. As curvas DSC dos nanocomplexos apresentaram uma série de eventos endotérmicos e exotérmicos correspondentes a processos de decomposição, desidratação, fusão e volatilização que corroboram com as curvas termogravimétricas. Todos os complexos lantanídicos obtidos apresentaram dimensões nanométricas, e o complexo de neodímio apresentou a estrutura mais cristalina. / The search for technological innovations in recent years increasingly intensifies. In this context, two major groups, the lanthanides and hydantoins stand out with important contributions in many areas of research showing wide field of applications. In these terms, this research aims to synthesize and characterize complex of lanthanide ions: Eu+3, Ho+3, Er+3 and Nd+3 with 5-(4-methyl-phenyl)-3-phenyl-2-thioxo-imidazolidin-4-one (HPA) and a second linker, 1,10-fenatrolina (Phen), aiming to obtain complexes with biological properties. From the reaction between the chlorides of lanthanides with the respective organic ligands under reflux for approximately 8 hours and 60°C, were obtained complexes of europium, holmium, erbium and neodymium. The powder complexes were characterized using spectroscopic techniques, thermal and structural analyzes. The complexes of lanthanide ions showed elemental analysis results according to the proposed stoichiometry (1:3:1). The coordination of the ligands with lanthanide ions occurred through oxygen and sulfur atoms in the structure of 5 - (4-methylphenyl) -3-phenyl-2-thioxo-imidazolidin-4-one (HPA) and nitrogen atoms (C = N) of 1,10'- phenanthroline, which can be observed in the infrared spectra, through the displacement of these bands present in free and coordinated ligands. UV-Vis spectra showed discrete displacements and changes in the intensities of the absorption bands of the complex compared to the HPA binder. The TG/ DTG curves HPA binder 3 had decomposition steps, while the complexes showed 4 and 5 steps. The complex synthesized Er+3 showed higher thermal stability. The DSC curves of the complexes showed a series of endothermic and exothermic events corresponding to decomposition processes, dehydration, fusion and volatilization, corroborating the thermogravimetric curves. All lanthanide complexes obtained showed nanometric dimensions, and neodymium complex presented the most crystalline structure.

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