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Conception et synthèse d'antagonistes du récepteur de la ghréline basés sur le motif 1,2,4-triazole 3,4,5-trisubstitué / Design and synthesis of ghrelin receptor antagonists based on the 3,4,5-trisubstituted 1,2,4-triazole scaffoldBlayo, Anne-Laure 17 September 2010 (has links)
La ghréline, une hormone peptidique principalement synthétisée au niveau de l'estomac, est le ligand endogène du récepteur des sécrétagogues de l'hormone de croissance appelé GHS-R1a. Elle est impliquée dans de nombreux processus biologiques dont principalement la sécrétion de l'hormone de croissance et la régulation de l'homéostasie énergétique. En raison de ses propriétés orexigènes et adipogènes, la ghréline est un outil puissant pour lutter contre les déséquilibres énergétiques. Développer des antagonistes de son récepteur représente ainsi une stratégie prometteuse pour la découverte de nouvelles pharmacothérapies contre l'obésité.Cette thèse est consacrée au développement d'antagonistes du récepteur de la ghréline dont la structure est basée sur une plateforme peptidomimétique : le 1,2,4-triazole 3,4,5-trisubstitué. Notre objectif est de concilier au mieux l'affinité et l'activité de nos ligands vis-à-vis du GHS-R1a avec des propriétés optimisées permettant de favoriser une bonne biodisponibilité orale. Nous nous sommes basés sur une synthèse rapide et efficace de ces composés pour réaliser des études approfondies de relations structure-activité et structure-propriété. En optimisant successivement les différentes positions autour du motif triazole, des compromis intéressants ont été obtenus. Nous avons ainsi identifié des antagonistes affins du récepteur qui présentent une stabilité microsomale suffisante et une perméabilité membranaire satisfaisante pour envisager des études in vivo. / Ghrelin, a peptidic hormone which is mainly synthesized in the stomach, is the endogenous ligand of the growth hormone secretagogue receptor named GHS-R1a. It is involved in numerous biological processes such as the growth hormone secretion and the control of energy homeostasis. Because of its orexigenic and adipogenic properties, ghrelin is a potent tool to control energy imbalance. Developing ghrelin receptor antagonists represents a promising strategy for the discovery of anti-obesity new drugs.This thesis is devoted to the development of ghrelin receptor antagonists based on a peptidomimetic scaffold: the 3,4,5-trisubstituted 1,2,4-triazole. Our aim is to combine ligand affinity and activity towards GHS-R1a with optimized properties which enable to promote a good oral bioavailability. We based our work on a rapid and efficient synthesis of our compounds to carry out detailed structure-activity and structure-property studies. By successively optimizing the different positions around the triazole scaffold, interesting compounds were obtained. We have thus identified receptor antagonists which exhibit sufficient microsomal stability and satisfactory membrane permeability to consider in vivo studies.
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Nouveaux matériaux commutables à base de ligands polyazotés : extension aux systèmes polyfonctionnels / New switchable materials based on N-donor ligands : towards the polyfunctional systemsBenaicha, Bouabdellah 29 September 2017 (has links)
Le travail présenté dans ce manuscrit concerne la conception et les études magnéto-structurales de nouveaux systèmes de Fe(II) à transition de spin (TS), en particulier ceux faisant intervenir les tétraazamacrocycles fonctionnalisés et les ligands de type 4-R-1,2,4-triazole. L’objectif principal est l’étude de l’effet de substitution ou de solvants (ou mélange de solvants) sur le comportement élastique de ces matériaux originaux. Dans un premier temps, nous avons étudié l’effet de solvant et contre-ions sur les propriétés de commutation, dans une série des complexes [Fe(L2)](X).nH2O (L2 = 1,8-bis(2’-pyridylméthyl)-1,4,8,11-tétraaza-cyclotétradécane, X = 2(tcm)- = 2[C(CN)3]-, n = 2 (1) ; X = [Ni(CN)4]2-, n = 1 (2) ; X = (BF4)-, n = 1 (3)). Cette étude a clairement élucidé l’effet crucial des interactions hydrogène, à travers les contre-ions et les molécules de solvants, sur la coopérativité observée dans la série des trois sels. Dans un second temps, l’utilisation des ligands de type 4-R-1,2,4-triazole nous a permis l’étude de deux systèmes commutables : (i) le premier concerne un complexe trinucléaire de formule [Fe3(furmetrz)6(tcnsme)6] (furmetrz = 4-(furan-2-ylmethyl)-1,2,4-triazole ; (tcnsme)- = 1,1,3,3-tétracyano-2- thiométhylpropenure), pour lequel les études magnétiques ont mis en évidence une transition thermique en deux étapes et un effet LIESST avec une T(LIESST) de 58 K. La comparaison de ce dérivé à d’autres systèmes similaires, mais présentant une transition de spin en une seule étape, révèle que la présence de deux étapes est favorisée par de fortes interactions le long de l’axe du trimère ; (ii) le second système concerne l’étude de plusieurs séries de matériaux polyfonctionnels exhibant la transition de spin et la photoluminescence. Le résultat le plus marquant concerne la synthèse et l’étude du complexe mononucléaire [Fe(naphtrz)6](tcnsme)2.4CH3CN (naphtrz = N-(1,2,4-triazol-4-yl)-1,8-naphthalimide) pour lequel les études magnétiques et optiques ont montré l’existence des deux propriétés, d’une manière synergétique. Ce résultat prouve la possibilité de contrôler, sans ambiguïté, les propriétés optiques par des excitations extérieures telles que la température, la pression, la lumière, … Au-delà de l’aspect fondamental, ce travail ouvre aussi des perspectives très originales pour l’utilisation de ces matériaux comme capteurs ou étalons de température. / This work is dedicated to the design and magnetostructural studies of new Fe(II) spin crossover (SCO) systems, in particular those involving the functionalized macrocycle and the 4-R-1,2,4-triazole triazole ligands.The principal objective concerns the study of the substitution and solvent effects on the SCO characteristics. In the first step, we have studied the solvent and the counter-ion effects, on the SCO behavior, in the series [Fe(L2)](X).nH2O (L2 = 1,8-bis(2’-pyridylméthyl)-1,4,8,11-tétraaza-cyclotétradécane, X = 2(tcm)- = 2[C(CN)3]-, n = 2 (1) ; X = [Ni(CN)4]2-, n = 1 (2) ; X = (BF4)-, n = 1 (3)), based on the macrocycles ligands. We have clearly shown in this study that the strong cooperative effects are mediated by the water solvent molecules and the counter-ions involved in the hydrogen bonding in the crystal packing. In the second step, the use of the 4-R-1,2,4-triazole fuctionalized triazole ligands led us to two original switchable systems: (i) the first one concerns the trinnuclear complex of formulae Fe3(furmetrz)6(tcnsme)6] (furmetrz = 4-(furan-2-ylmethyl)-1,2,4-triazole; (tcnsme)- = 1,1,3,3-tetracyano-2- thiométhylpropenide), for which the magnetic study reveals a two-step SCO transition and a LIESST effects with a T(LIESST) of 58 K. Examination of the intermolecular interactions in this complex and other parent trinuclear systems exhibiting complete one-step spin transition, revealed that the presence of the two-step behavior is clearly favored by strong inter-trimer interactions along the trimer axis; (ii) the second system the design and syntheses of to several series of polyfunctional materials exhibiting SCO and luminescent behaviors. In this new way, the most significant result concerns an original discrete Fe(II) complex of formulae [Fe(naphtrz)6](tcnsme)2.4CH3CN (naphtrz = N-(1,2,4-triazol-4-yl)-1,8-naphthalimide), for which the magnetic and photoluminescent studies showed that this material exhibits synergetic SCO and luminescent behaviors. This proves the possibility to control the luminescent properties through simple external perturbations such as temperature, pressure, light irradiation,… In addition, beyond the fundamental aspect, this work open new innovative perspectives for the use of such original materials as sensors or standards of temperature.
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Polymères de Fe(II) à transition de spin à base de triazole : synthèse, étude des propriétés et nouvelles potentialités / Fe(II) spin crossover polymers based on triazole ligands : synthesis, study of properties and new potentialitiesDaro, Nathalie 18 December 2013 (has links)
Les polymères de Fe(II) à transition de spin à base de ligand triazole [Fe(Rtrz)3]X2 possèdent des propriétés de commutation proches de la température ambiante. Cette bistabilité détectable à la fois par voie optique et magnétique leur confère un intérêt applicatif. Il est maintenant acquis que leurs propriétés sont très dépendantes de leur composition : la nature du substituant du ligand 1,2,4-triazole et/ou de l’anion et/ou du taux d’hydratation. Ce travail a permis d’aborder diverses problématiques. L’influence du phénomène de déshydratation/réhydratation sur les propriétés de transition de spin est d’abord étudiée pour quelques complexes. Ensuite, la synthèse de nouveaux matériaux est envisagée grâce à la méthode des alliages moléculaires. Puis, l’influence des paramètres de synthèse sur les propriétés est examinée pour quatre composés choisis. Enfin, l’effet du traitement en milieu supercritique sur les caractéristiques de ces composés moléculaires est étudié. / Spin crossover polymers based on Fe(II) and 1,2,4-triazole ligands [Fe(Rtrz)3]X2 have switching capabilities near room temperature. Optical and magnetic bistabilities observed for these systems confer potential applications. It is well established that their properties are highly dependent on their composition : the nature of the 1,2,4-triazole substituent, the anion and the rate of hydration. Our work has addressed several different topics. The influence of the dehydration/rehydration phenomenon on the spin transition is first studied for some complexes. Next, molecular alloy method is considered to obtain new materials. Then, the influence of synthesis parameters on the properties is examined for four selected compounds. Finally, the effect of treatment in a supercritical medium on the molecular characteristics of these compounds is studied.
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Characterization of a leaf-type catalase and its enzymatic regulation in sweet potato (Ipomoea batatas (L.))AFIYANTI, MUFIDAH 14 July 2011 (has links)
A major sweet potato leaf-type catalase was detected and identified from fullyexpandedmature leaves using in-gel activity staining assay with native- andSDS-PAGEs. The putative catalase activity band was inhibited by a catalaseinhibitor 3-amino-1,2,4-triazole. The major leaf-type catalase activity wasoptimal over 8, and was significantly repressed by £]-mercaptoethanol. However,its activity was much less affected by temperature within the range of 5 to 450C.Temporal and spatial expression showed that it was specifically detected inleaves, but not in roots and stems. Its activity increased from the immature L2leaves, and reached the maximal at the fully-expanded mature L3 leaves, thenslightly decreased in partial yellowing senescent L4 leaves, and was almost notdetected in completely yellowing L5 leaves similar to folding unopenedimmature L1 leaves. The catalase level showed approximately inversecorrelation with the H2O2 amounts in leaves of different developmental stages.Dark and ethephon, an ethylene-releasing compound, also temporarily enhancedthe catalase activities from 6 h to 24 h, however, the enhanced activitydecreased from 24 h to 48 h in detached leaves after treatment. The catalaselevel also showed approximately negative correlation with the H2O2 amounts intreated leaves. The major leaf-type catalase activity was repressed by EGTA,and the repression can be reversed by exogenous CaCl2. The major leaf-typecatalase activity was also repressed by calmodulin inhibitor chlorpromazine,and the repression can be reversed by exogenous purified SPCAM calmodulinfusion protein. Chlorpromazine-treated leaves also elevated H2O2 amount.Based on these data we conclude that a major leaf-type catalase with maximalactivity in L3 leaf was identified in sweet potato. Its activity was temporarilyenhanced by dark and ethephon, and was modulated by external calcium ion(Ca2+) and calmodulin. A possible physiological role and function in associationwith cellular H2O2 homeostasis in cope with developmental and environmentalcues in sweet potato leaves is suggested.
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Contribution to the Triazole-Based Fe(II) Spin-Crossover (SCO) materials : some achievements and new questions / Contribution à l’étude de matériaux à transition de spin à base de FeII et de triazole : avancées et nouvelles questionsPittala, Narsimhulu 24 November 2016 (has links)
Ces dernières années, les matériaux à transition de spin (TS) ont suscité un intérêt marqué en raison de leurs applications potentielles, notamment en tant que capteurs ou dispositifs électroniques; typiquement, ces complexes présentent - via un stimulus externe (ex. : température, rayonnement) - une transition de spin réversible "Haut Spin (HS) Bas Spin (BS)". Dans ce contexte, le travail présenté a porté sur la conception et les études magnétostructuralesde monocristaux de nouveaux systèmes FeII à TS à base de ligands 4-R-1,2,4-triazole comprenant un espaceur alkyl, en combinaison avec soit (i) des entités tétracyanométallates inorganiques ([M(CN)4]2-, M = NiII, PtII, PdII) ou (ii) des cyanocarbanions organiques spécifiques ((tcnsR')-: anions 1,1,3,3-tétracyano-2 thioalkylpropénide) - et ce afin de comprendre in fine l'origine physico-chimique de la forte coopérativité dans ces matériaux remarquables, mais aussi de rationaliser le contrôle et l’optimisation des propriétés de TS. Dans un premier temps, un nouveau sel de polymère 1D [Fe(bntrz)3][Pt(CN)4].H2O (1) - présentant une TS abrupte et une résilience exceptionnelle lors de cycles répétés de commutation - a été synthétisé; les études structurales fines - réalisées sur monocristaux - des états HS et BS ont clairement révélé l'impact des interactions à longue distance sur les propriétés de la TS dans ce système. Ensuite, la substitution de l'anion « rigide » tétracyanométallate ([Pt(CN)4]2-) par l'entité plus « flexible » (tcnset)- nous a conduit au premier exemple de complexe neutre trinucléaire à base de triazole [Fe3(bntrz)6(tcnset)6] (2) présentant une TS complète en une seule étape au-dessus de la température ambiante. La variation systématique du substituant R' de l'anion fonctionnalisé(tcnsR')- a permis l’obtention de deux nouveaux systèmes à TS, à savoir le complexe trinucléaire neutre [Fe3 (bntrz)6(tcnspr)6] (3) et le dérivé 1D [Fe3(bntrz)8(tcnsme)4].(tcnsme)2,4H2O (4), avec des caractéristiques structurales et des comportements de TS distincts. Enfin, dans le but d'évaluer précisément l'impact de différents substituants en 4ème position sur le ligand 1,2,4-triazole, deux nouveaux matériaux 3D basés sur le triazole 2-(3-(4H-l,2,4-triazol-4-yl)propyl)isoindoline-1,3-dione (phtptrz) - i.e. {Fe3(μ2-phtptrz)6[μ2-Pt(CN)4]3}.C2H5OH,5.5H2O (5) et {Fe(phtptrz)[Pt(CN)4].H2O} (6) - ont été synthétisés et caractérisés; une TS en deux étapes est observée pour le composé 5, tandis que le dérivé 6 exprime un comportement paramagnétique caractéristique de l’état de spin S = 2. / In recent years, the spin-crossover (SCO) materials have attracted much interest because of their potential applications such as sensors or electronic displays; these complexes typically exhibit - via an external disturbance (e.g. temperature, radiation) - a reversible “High Spin (HS) Low Spin (LS)” spin transition. In this context, the present work has focused on the design and the magneto-structural investigations of single crystals of novel FeII SCO systems based on 4-R-1,2,4-triazole ligands including an alkyl spacer - with either (i) inorganic tetracyanometallates ([M(CN)4]2-, M = NiII, PtII, PdII) or (ii) specific organic cyanocarbanions ((tcnsR’)-: 1,1,3,3-tetracyano-2-thioalkylpropenide anions) - in order to ultimately understand the physicochemical origin of the strong cooperativity in such striking materials, but also to rationalize the tuning of the SCO properties. At first, a new 1D polymer [Fe(bntrz)3][Pt(CN)4].H2O (1) salt - exhibiting an abrupt spin transition and an exceptional resilience upon repeated switching - has been synthesized; the accurate single crystal investigations of both HS and LS states of the latter clearly revealed the impact of the longrange interactions on SCO properties in this system. Then, the substitution of the ‘rigid’ [Pt(CN)4]2- tetracyanometallate anion by the more ‘flexible’ (tcnset)- entity lead us to the first example of triazole-based SCO FeII trinuclear neutral complex [Fe3(bntrz)6(tcnset)6] (2) exhibiting a complete one-step spin transition above room temperature. The systematic variation of the R’ substituent from the functionalized (tcnsR’)- anion resulted in two new FeII SCO systems, i.e. the neutral trinuclear complex [Fe3(bntrz)6(tcnspr)6] (3) and the 1D [Fe3(bntrz)8(tcnsme)4](tcnsme)2.4H2O (4) derivative, with distinct structural characteristics and SCO behaviours. Finally, with the purpose to further evaluate the impact of different substituents at the 4th position onto 1,2,4-triazole ligand, two new 3D materials based on the functionalised triazole 2-(3-(4H-1,2,4-triazol-4-yl)propyl)isoindoline-1,3-dione (phtptrz) - {Fe3(μ2-phtptrz)6[μ2-Pt(CN)4]3}.C2H5OH,5.5H2O (5) and {Fe(phtptrz)[Pt(CN)4].H2O} (6) - have been synthesized and characterized; a two-step SCO behaviour is observed only in 5, while 6 shows a characteristic paramagnetic behavior.
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Sílica mesoporosa como suporte sólido para o ancoramento da molécula 4-amino-3-hidrazino-5-mercapto-1,2,4-triazole e aplicação na adsorção de Cu(II), Cd(II), Ni(II), Pb(II) e Co(II) em amostras aquosas / Mesoporous silica as the solid support for the anchoring of 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole molecule and application in the adsorption of Cu (II), Cd (II), Ni (II), Pb (II) and Co (II) in aqueous samplesIvassechen, Janaíne do Rocio [UNESP] 07 January 2016 (has links)
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Previous issue date: 2016-01-07 / A determinação direta de metais presentes em baixas concentrações em amostras de águas naturais é geralmente dificultada devido à presença de espécies interferentes. Os metais que foram estudados, Cu (II), Pb(II), Co (II), Ni (II) e Cd (II) são de interesse ambiental em razão de seu uso intensivo, distribuição e por serem absolutamente não-degradáveis podem acumular-se em matrizes ambientais manifestando toxicidade. Neste projeto desenvolveu-se a sílica como suporte sólido para o ancoramento da molécula 4-amino-3-hidrazino-5-mercapto-1,2,4-triazole e sua aplicação na adsorção/remoção de íons em solução aquosa. O material foi caracterizado por espectroscopia na região do infravermelho (FTIR), o qual apresentou bandas em 1690- 1649 e 790 cm-1 , característica de ligações N-H de aminas primárias do ligante. A ressonância magnética nuclear de 13C e 29Si (RMN) comprovam o ancoramento do ligante. As medidas de área de superfície específica pelo método de BET e diâmetro de poro resultaram em uma área de 795,51 ± 1,14 m2 g-1 e poros numa gama de 1,1 a 7,1 nm. A Microscopia Eletrônica de Varredura (MEV) mostrou que o material tem formato esférico com tamanhos aproximadamente de 10 μm e a Análise por Energia Dispersiva de Raios X (EDX) mostrou uma distribuição homogênea do sililante por toda a superfície do material. Com isso, confirmou-se a ocorrência da reação de modificação. O material foi aplicado em estudos de adsorção para determinação da sua capacidade máxima, bem como estudos da influência do pH e estudos cinéticos no processo de equilíbrio Os experimentos foram realizados pelo método de batelada. O primeiro teste foi o pHPZC, que indica a melhor faixa de pH (5-9) para a adsorção. Os estudos de adsorção dos metais em solução apresentaram o melhor resultado quando o pH era igual a 6, o equilíbrio de adsorção foi atingido depois de 50 minutos de agitação. Para todas as espécies investigadas o processo de adsorção é melhor descrito pelo modelo de pseudo- segunda ordem. Com esses parâmetros estabelecidos os valores de capacidade máxima de adsorção foram encontrados, sendo 0,129; 0,102; 0,105; 0,113; e 0,076 mmol g-1 para o Cu, Ni, Pb, Co e Cd, respectivamente. A sílica modificada foi aplicada na pré-concentração de Cu (II) em amostras aquosas. Com um fator de enriquecimento de 20 vezes, a coluna provou ser estável ao longo de 24 ciclos de adsorção/dessorção. / The direct determination of metals present at trace levels in natural water samples is generally difficult due to the presence of interfering species. Metals that were studied, Cu(II), Pb(II), Co(II), Ni(II) and Cd(II) are of environmental interest because of its intensive use, distribution, and as a consequence of its non-degradability can be accumulated in environmental matrices manifesting toxicity. In this project was developed a mesoporous silica as solid support for the anchoring of 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole molecule to be applied in the adsorption/removal of metals from aqueous solution. The material was characterized by infrared spectroscopy (FTIR), which showed bands at 1649 and 1690- 790 cm-1, characteristic of NH bonds of primary amines, existing in molecule ligand. The nuclear magnetic resonance 13C and 29Si (NMR) confirm the anchoring of the ligand. Measurements of specific surface area by the BET method and pore diameter resulted in an area of 795.51 ± 1.14 m2 g-1 and pores in a range from 1.1 to 7.1 nm. Scanning Electron Microscopy (SEM) showed that the material has spherical shape with sizes of approximately 10 μm and the analysis by Energy Dispersive X-ray (EDX) showed a homogeneous distribution of silylant over material surface. Thus, it was confirmed the occurrence of the modification reaction. The material was applied in adsorption studies to determine its maximum adsorption capacity, as well as studies of the influence of pH and kinetic studies on the balance process. The experiments were performed by the batch method. The first test was the pHPZC which indicates the best pH range (5-9) for the adsorption. Adsorption studies showed the best results when pH was near 6 and the adsorption equilibrium was attained after 50 minutes of stirring time. For all species investigated the adsorption process is better described by the pseudo- second order kinetic model. With these parameters established the maximum adsorption capacity values found were 0.129, 0.102, 0.105, 0.113 and 0.076 mmol g-1 for Cu(II), Ni(II), Pb(II), Co(II) and Cd(II), respectively. Modified silica was also applied in the preconcentration of Cu(II) from aqueous samples with 20 fold enrichment factor and the packed column proved to be stable over 24 cycles of adsorption/desorption.
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Potencial terapêutico antiobesidade do 3-amino-1,2,4-triazole: repercussões no perfil lipídico sistêmico-hepático em um modelo murino dietético para a síndrome metabólica / Antiobesity therapeutic potential from 3-amino-1,2,4-triazole: repercussions in the systemic and liver lipid profile in a high fat-induced metabolic syndrome miceSilva, Marcos Antonio Eleutério da 26 October 2016 (has links)
The metabolic syndrome (MetS) is characterized by an association of factors that reinforce each other mutually; such as central obesity, hypertension, type 2 diabetes and dyslipidemias. This scenario is associated to reactive species of oxygen and nitrogen production, aggravated by obesity status, triggering imbalance between oxidation and reduction reactions (redox), resulting in oxidative stress and metabolic disorders. Among the antioxidants, it is highlighted the catalase role, responsible to hydrogen peroxide (H2O2) dismutation into oxygen and water. This compound is a substrate in lipolysis, energy control and inflammation. Thus, it is believed that the modulation of the H2O2 / catalase / redox balance-axis in MetS/Obesity, might produce an important therapeutic effect antiobesity and metabolic-liver changes. The aim was to evaluate effect antiobesity and the metabolic-liver changes induced by 3-amino-1,2,4-triazole (ATZ), a reputed catalase inhibitor on the 2O2 / catalase / redox balance-axis. For this, it was used at different doses (125, 250 and 500 mg.kg-1) in C57BL6 MetS mice-diet induced for 12 weeks. The ATZ-treated mice showed increased lipolysis (p<0.001) and decreased (p<0.001) levels of: diameter of adipocytes, body weight; distribution of epididymal fat,
adiposity index; expression of plasma leptin ; plasma and liver total cholesterol (p<0.01; ATZ500, p<0.001), triglycerides (,p<0.001) and non-esterified free fatty acids (p<0.001); basal glycemia, during the glucose tolerance test (p<0.001), insulin resistance test (p<0.001) and pyruvate test (p<0.001); the index to indirect evaluation of insulin resistance and plasma insulin (p<0.01). Decreased (p<0,05) of liver-gene expression to: insulin receptor (p<0.05); Glucose-6-phosphatase (G6Pase) and glucokinase (GCK) and increased gene expression to: phosphoenolpyruvate carboxykinase 2 (PcK2) (p<0.01); the fatty acid translocase protein (CD36 / FAT) (p<0.001) and lipid binding protein / adipocyte fatty acids (aP2) (p<0.001). Besides, it ocurred decreased in catalase activity and the levels of reactive substances to thiobarbituric acid (TBARS) (p<0.05). The ATZ showed to be a potent lipolytic inducer, able to promote an important antiobesity effect, capable to: reduce body weight, regulate the lipid balance between plasma and liver, improve glycaemic control and insulin sensitivity, as well as to modulate the redox imbalance in animal MetS induced by high fat diet. / A síndrome metabólica (SMet) é caracterizada pela associação de fatores potencialmente prejudiciais que se reforçam mutualmente, como obesidade central, hipertensão, diabetes mellitus 2 e dislipidemias. Este cenário é acompanhado pela produção de espécies reativas de oxigênio e nitrogênio, agravado pela obesidade, que podem implicar desequilíbrio entre as reações de oxidação / redução (redox), culminando no estresse oxidativo e alterações metabólicas. Dentre os antioxidantes, destaca-se a catalase, responsável pela dismutação do peróxido de hidrogênio (H2O2) em água e oxigênio. Este composto é um substrato em vias como as relacionadas à lipólise, controle energético e inflamação. Assim, postula-se que a modulação do eixo H2O2/catalase/equilíbrio redox na SMet / obesidade, represente um importante efeito terapêutico antiobesidade com importantes modificações sistêmico-hepáticas relacionadas à lipólise. Diante disso, objetivou-se avaliar as ações antiobesidade e
lipolíticas sistêmico-hepáticas, induzidas pelo 3-amino-1,2,4-triazole (ATZ), um reputado inibidor da catalase, sobre o eixo H2O2/CAT/equilíbrio redox, na SMet. Para tanto, utilizou-se este em diferentes doses (125, 250 e 500 mg.kg-1) na dieta de animais C57BL6 com SMet por 12 semanas. Os camundongos tratados apresentaram aumento da lipólise (p<0,001) e diminuição (p<0,001): no diâmetro dos adipócitos; no peso corporal; na distribuição de tecido adiposo; no índice de adiposidade; na expressão plasmática de leptina; nos níveis plasmáticos e hepáticos do colesterol total, triglicerídeos e ácidos graxos livres não esterificados; na glicemia durante os teste de tolerância à glicose, resistência à insulina e do piruvato; no índice de avaliação indireta da resistência à insulina e nos níveis plasmáticos de insulina (p<0,01). Diminuição (p<0,05) da expressão gênica no fígado para: receptor para a insulina; Glicose-6-fosfatase (G6Pase) e Glicoquinase (GCK). Aumento da expressão gênica para: fosfoenolpiruvato carboxiquinase 2 (PcK2) (p<0,01); proteína translocase de ácido graxo
(CD36/FAT) (p<0,001) e proteína ligadora de ácidos graxos (aP2) (p<0,001). Além da diminuição da atividade da catalase e níveis das substâncias reativas ao ácido tiobarbitúrico (TBARS) (p<0,05). O ATZ mostra ser um potente indutor lipolítico capaz de promover um importante efeito antiobesidade, ao diminuir o peso corporal, regular o balanço lipídico entre o plasma e o fígado, melhorar o perfil glicêmico e a sensibilidade à insulina, além de modular o desequilíbrio redox em animais com SMet induzida por dieta hiperlipídica.
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Préparation et dérivatisation de 4H-pyrido[e][1,3]oxazinones : une contribution à la diversité chimique / Preparation and derivatization of 4H-pyrido[e][1,3]oxazinones : a contribution to chemical diversityLe Falher, Laetitia 07 November 2014 (has links)
Ce manuscrit porte sur la synthèse et les applications d'une nouvelle série de composés hétéroaromatiques : les 4H-pyrido[e][1,3]oxazin-4-ones. La première partie de ce manuscrit présente la préparation de ces squelettes via une réaction d'O-arylation intramoléculaire. La seconde partie du manuscrit repose sur la réactivité de ces entités chimiques et de leur utilisation en tant qu'intermédiaires de synthèse. La fonctionnalisation des 4H-pyrido[e][1,3]oxazin-4-ones, via des réactions de couplage pallado-catalysées, a permis d'obtenir des systèmes polyfonctionnalisés plus complexes. Les pyrido-oxazinones ont également été transformées, en une étape, en divers petits hétérocycles d'intérêt : les 1,3,5-triazines, les 1,2,4-triazoles et les 1,2,4-oxadiazoles. La dernière partie du manuscrit est consacrée à l'utilisation des molécules synthétisées comme potentielles sondes fluorescentes pour la détection de protéines oxydées. / This work focused on the synthesis and applications of a novel series of heteroaromaticcompounds: the 4H-pyrido[e][1,3]oxazin-4-ones. The first part of this thesis presents thepreparation of these pyrido-oxazinones via an intramolecular O-arylation reaction. The secondpart of this work relies on the reactivity of these chemical entities and their use as buildingblocks. The functionalization of the 4H-pyrido[e][1,3]oxazin-4-ones has been studied viacross-coupling reactions to obtain more elaborated structures. The pyrido-oxazinones werealso converted, in one step, into other diverse small molecules of interest: 1,3,5-triazines,1,2,4-triazoles and 1,2,4-oxadiazoles. The last part of this thesis was devoted to the use of theobtained heterocycles as potential fluorescent probes for the detection of carbonylatedproteins.
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Síntese e aplicação de sílica modificada na adsorção de Cu(II), Cd(II) e As(V) em meio aquoso: pré-concentração em amostras de águas naturais / Synthesis and application of modified silica in Cu (II), Cd (II) and As (V) adsorption in aqueous media: preconcentration in natural water samples.Wondracek, Marcos Henrique Pereira [UNESP] 05 October 2017 (has links)
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Previous issue date: 2017-10-05 / Item merged in doublecheck by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-12-07T17:59:08Z
Item was identical to item(s): 153113, 153193 at handle(s): http://hdl.handle.net/11449/152063, http://hdl.handle.net/11449/152164 / Este trabalho relata o desenvolvido de métodos analíticos que visa à determinação de algumas espécies tóxicas e potencialmente tóxicas de metais e metalóides em níveis ultra-traço em amostra de água naturais, utilizando uma técnica analítica menos sensível, como a espectrometria de absorção atômica em chama (FAAS). Essa técnica foi escolhida por ser relativamente simples e possuir baixo custo operacional. A técnica de extração em fase sólida (EFS), utilizando um novo material sorvente, foi utilizada para separar e pré-concentrar os analitos. Este estudo demonstra o procedimento de uma nova rota sintética via co-condensação visando à produção de uma sílica mesoporosa organofuncionalizada com o ligante 4-amino-3-hidrazino-5-mercapto-1,2,4-triazole e, sua utilização como sorvente para pré-concentração/análise de especiação de íons metálicos em amostras de água. O material produzido foi caracterizado por espectroscopia na região do infravermelho (FTIR), BET, ressonância magnética nuclear (RMN) de 29Si e 13C, dentre outras. As características adsortivas desse material foram estabelecidas em estudos de batelada, onde se estudou o efeito do pH, cinética de adsorção e capacidade máxima de adsorção. A otimização multivariada foi utilizada para obtenção das melhores condições químicas e de fluxo no sistema de pré-concentração, permitindo avaliar as interações principais e secundárias entre os fatores. Por meio da análise dos espectros obtidos por FTIR foi possível observar bandas de estiramento C–H, C–Cl e (NH2) oriundos da fração orgânica do material. A área superficial foi de 369,84 m2 g-1com diâmetro médio de poros em 7,1 nm, relacionados a materiais mesoporosos. Os resultados obtidos por RMN de 29Si comprovam a formação do material híbrido, sintetizado por co-condensação, e o RMN de 13C confirma o ancoramento do ligante na matriz.
O pH que favorece a adsorção dos íons foi 5,0 para Cu(II) e 3,0 para Cd(II) e As(V). O modelo cinético de pseudo segunda ordem apresentou melhor ajuste aos dados experimentais, indicando adsorção química. Os dados de sorção desses íons metálicos mostraram bom ajuste ao modelo de Langmuir, com capacidade máxima de adsorção próxima aos valores obtidos experimentalmente, 0,057, 0,018 e 0,060 mmol g-1 para Cu(II), Cd(II) e As(V), respectivamente, indicando que a sorção ocorre em monocamada. Os parâmetros analíticos encontrados para o Cu(II) foram: fator de pré-concentração de 18,1; intervalo linear de 10,0 – 200,0 µg L-1 (R = 0,999) e LD de 1,45 µg L-1. Para o Cd(II): fator de pré-concentração de 15,8; intervalo linear de 2,0 – 100,0 µg L-1 (R = 0,999) e LD de 0,38 µg L-1. Para o As(V): fator de pré-concentração de 5,0; intervalo linear de 0,25 – 2,5 µg L-1 (R = 0,999) e LD de 0,039 µg L-1. A exatidão foi checada pelo método de adição e recuperação e/ou método comparativo com GFAAS ou ICP OES. As recuperações variaram de 97 – 106% (Cu), 100 – 105% (Cd), 88 – 103% (As(V)) e 96 – 106% (As(total)). Os resultados para Cu(II) determinados com os métodos propostos foram concordantes com os obtidos com o método comparativo. Conclui-se que o material produzido apresenta bom potencial para ser aplicado na extração/pré-concentração de cobre, cádmio e análise de especiação inorgânica de arsênio. Provou-se também que baixos limites de detecção e quantificação podem ser obtidos mesmo utilizando uma técnica menos sensível como a FAAS. / This paper reports on the development of analytical methods for the determination of some toxic and potentially toxic species in ultra - trace levels in natural water samples using a less sensitive analytical technique such as flame atomic absorpti on spectrometry (FAAS). This technique was chosen because it is relatively simple and has a low operating cost. The solid phase extraction technique (SPE) using a new sorbent material was used to separate and preconcentrate the analyte. This study demonstr ates the procedure of a new synthetic route using the technique of the co - condensation for the production of a mesoporous organo - functionalised silica with the 4 - amino - 3 - hydrazino - 5 - mercapto - 1,2,4 - triazole ligant and its use as a sorbent for preconcentrati on/ analysis of metal ion s speciation in water samples. The material produced was characterized by infra - red spectroscopy (FTIR), BET, 29 Si and 13 C nuclear magnetic resonance (NMR), among others. The adsorptive characteristics of this material were establis hed in batch studies, where the effect of pH, adsorption kinetics and maximum adsorption capacity were studied. Multivariate optimization was used to obtain the best chemical and flow conditions in the preconcentration system, allowing the evaluation of th e main and secondary interactions among the factors. By means of the analysis of the spectra obtained by FTIR, it was possible to observe C - H, C - Cl and (NH 2 ) stretch bands from the organic fraction of the material. The surface area was 369.84 m 2 g - 1 with a verage pore diameter at 7.1 nm related to mesoporous materials. The results obtained by 29 Si NMR prove the formation of the hybrid material, synthesized by co - condensation, and the 13 C NMR confirms the anchoring of the ligan t in the matrix. The pH 5.0 it w as favors the adsorption of the ions Cu (II), the pH 3.0 it was favors the adsorption of the Cd (II) and As (V). The kinetic model of pseudo second order showed better adjustment to the experimental data, indicating chemical adsorption. The adsorption data of Cu (II), Cd (II), and As (V) were similar to those of the Langmuir model, with a maximum adsorption capacity of 0.057, 0.018 and 0.060 mmol g - 1 for Cu (II), Cd(III) and As(V) , respectively, indicating that the sorption occurs in monolayer. The analyt ical parameters for Cu (II) were: preconcentration factor of 18.1; linear range of 10.0 - 200.0 μg L - 1 (R = 0.999) and LD of 1.45 μg L - 1 . For Cd (II): preconcentration factor of 15.8; linear range of 2.0 - 100.0 μg L - 1 (R = 0.999) and LD of 0.38 μg L - 1 . Fo r As (V): preconcentration factor of 5.0; linear range of 0.25 - 2.5 μg L - 1 (R = 0.999) and LD of 0.039 μg L - 1 . Accuracy was checked by addi tion and recovery method of the standard and/ or comparative method with GFAAS or ICP OES. The recovery ranged from 97 - 106% Cu(II), 100 - 105% Cd (II), 88 - 103% As (V) and 96 - 106% As (total)). The results for Cu (II) determined with the proposed methods were concordant with those obtained with the comparative. It is concluded that the material produced can be successfully applied in the extraction / preconcentration of copper, cadmium and analysis of inorganic speciation of arsenic and low limits of detection and quantification can be obtained even using a less sensitive technique such as FAAS.
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