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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

Síntese de (5-trifluormetil-1H-pirazol-1-IL)(quinolin-4-IL)metanonas de interesse farmacológico / Synthesis of (5-trifluoromethyl-1H-pyrazol-1-YL)(quinolin-4-YL)methanones of pharmacological interest

Nogara, Pablo Andrei 22 July 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A convergent synthesis of a series of 16 new polysubstituted (5-hydroxy-5-(trifluoromethyl)-4,5-dihydro-1H-pyrazol-1-yl)(quinolin-4-yl)methanones, starting from isatin and alky(aryl/heteroaryl) ketones, is described. The diheteroaryl methanones were achieved at yields of up to 95% by a (3 + 2) cyclocondensation reaction involving 4-alkyl(aryl/heteroaryl)-4-methoxy-1,1,1-trifluorobut-3-en-2-ones (by two-step reaction) and 2-alkyl(aryl/heteroaryl)-4-carbohydrazides (by three-step reaction). Subsequently, representative dehydrated heterocyclic derivatives were obtained from the respective 5-hydroxy-2-pyrazoline moieties by classical dehydration reactions, which resulted in the corresponding (5-(trifluoromethyl)-1H-pyrazol-1-yl)(quinolin-4-yl)methanones (three examples) at yields of 69 82%. The compounds were characterized by one- and two-dimensional 1H/13C NMR, X-ray diffraction, GC-MS and elemental analysis. The subsequent cytotoxicity evaluation showed that compounds with aromatic groups at the 2-position of the quinoline and a methyl moiety at the 3-position of the pyrazole have significant cytotoxicity in human leukocytes at high concentrations (200 μM). / Uma síntese convergente de uma série de 16 novos poli-substituídos (5-hidroxi-5-(trifluorometil)-4,5-di-hidro-1H-pirazol-1-il)(quinolin-4-il)metanonas, a partir da isatina e alquil(aril/heteroaril)cetonas, é descrito. As diheteroarilmetanonas foram obtidas com rendimentos de até 95% por uma reação de ciclocondensação (3 + 2) envolvendo 4-alquil(aril/heteroaril)-4-metóxi-1,1,1-trifluorbut-3-en-2-onas (reação em dois passos) e 2-alquil(aril/heteroaril)-4-carbohidrazidas (reação em três passos). Subsequentemente, os representantes desidratados dos heterociclos foram obtidos a partir das respectivas porções de 5-hidróxi-2-pirazolina por reações de desidratação clássicas, o que resultou nas correspondentes (5-(trifluormetil)-1H-pirazol-1-il)(quinolin-4-il )metanonas (três exemplos) com rendimentos de 69-82%. Os compostos foram caracterizados por RMN de 1H e 13C uni e bidimensional, difração de raios-X, CG-EM e análise elementar. As posteriores avaliações da citotoxicidade mostraram que os compostos com grupos aromáticos na posição 2 da quinolina e o grupo metila na posição 3 do pirazol, possuem significativa citotoxicidade em leucócitos humanos em concentrações elevadas (200 μM).
2

Evaluation of physico-chemical properties of biorefinery-derived amphiphilic molecules and their effects on multi-scale biological models / Evaluation des propriétés physico-chimiques de molécules amphiphiles dérivées de la bio-raffinerie et leurs effets sur des modèles biologiques multi-échelles

Lu, Biao 16 October 2015 (has links)
Aujourd'hui, un grand nombre de nouvelles molécules peuvent être synthétisées à partir de la biomasse. Les tensioactifs dérivés de sucre sont notamment considérés comme une alternative aux tensioactifs fossiles en raison de leur biodégradabilité et de leur biocompatibilité. Cependant, les études associant la caractérisation physico-chimique et les propriétés biologiques de ce type de tensio-actifs sont limitées. Il est ainsi difficile de prédire les propriétés d'un tensioactif à partir de sa structure chimique. L'établissement d'une méthodologie permettant de relier la structure des surfactants à leurs propriétés apparait pertinent. Dans ce travail, quatre surfactants dérivés de sucre ayant chacun une chaîne C8 liée à une tête glucose ou maltose par un groupe amide ont été caractérisés par leurs propriétés tensio-actives dans différentes solutions (eau et milieu biologique). Leurs interactions avec des protéines ont également été analysées. Concernant l'évaluation des propriétés biologiques, des tests de cytotoxicité/irritation ont été effectués sur trois modèles in-vitro : 1) modèle cellulaire 20 (cellules L929 cultivées en monocouche), Il) modèle cellulaire 30 (cellules L929 cultivées dans un gel de collagène), Ill) épiderme humain reconstitué. Les résultats indiquent que les quatre surfactants synthétisés présentent de bonnes propriétés tensio-actives et trois d'entre eux sont moins cytotoxiques que des tensioactifs de référence. Plusieurs hypothèses permettant de relier la structure chimique des molécules à leurs propriétés physico-chimiques et biologiques ont été proposées. Des travaux futurs permettront d'enrichir la base de données sur les relations structure-propriétés des tensioactifs issus de la biomasse, et de l'utiliser pour synthétiser des surfactants présentant des propriétés adaptées aux applications envisagées. / Nowadays, a wide variety of new molecules can derive from biomass. Among them, the family of sugar-based surfactants, which are considered as alternatives to fossil-based surfactants, due to their relatively high biodegradability and biocompatibility, exhibit interesting properties both in terms of their self-assembly and their ability to induce biological responses. In the study, for the purpose to analyse these properties, different methodologies have been established. In this work, physico-chemistry and cellular biology methodologies are associated to analyse the properties of pre-selected molecules characterized by gradua) structure modifications. Firstly, we have screened synthesized sugar-based surfactants according to their solubility and their ability to reduce surface tension of water. Four pre-selected molecules, with a C8 chain linked to a glucose or maltose head through an amide functional group, either under the form of carbamoyl (carbohydrate scaffold bearing the carbonyl) or alkylcarboxamide (the alkyl chain bearing the carbonyl), were then dissolved in water/ cell culture media for surface tension measurements. Their behaviors in solutions were characterized by Krafft points, Critical Micellar Concentrations or self-assembling properties through different methods. To evaluate the cytotoxic/ irritant effects of these molecules on cells and tissues, 3 in-vitro models were established: I) 2D cell culture mode! (L929 cell monolayer) II) 3D ce!! culture mode! (L929 cells embedded in collagen gel) and III) Reconstituted human epidermis (differentiated human keratinocytes). Corresponding experiments were carried out on these models with increasing complexity. Results show that the synthesized sugar-based surfactants, GlulamideC8, Glu6amideC8, Glu6amideC8' and MallamideC8 can reduce the surface tension of water solution to the came level as standard surfactants (Tween 20 and Hecameg). In the meantime, GlulamideC8, Glu6amideC8' and MallamideC8 present Iess cytotoxicity effects on L929 cells both in the monolayer model and the 3D mode! than Tween 20 and Hecameg. All synthesized and standard surfactants (GlulamideC8, Glu6amideC8, Gu6amideC8', MallamideC8, Tween 20 and Hecameg) have no significant cytotoxic/ irritant effects on reconstituted human epidermis at 1000 ig/mL after 48 h of topical application. Discussions have been made according to the results of experiments to establish possible structures/ physico-chemical properties - cytotoxicity relationships of these surfactants.

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