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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.
61

Investigação da influência da velocidade de liberação do fármaco metoprolol a partir da forma farmacêutica sobre seu processo de absorção e de seus enantiômeros / Influence of the input rate of metoprolol on the absorption of its enantiomers

Francinalva Dantas de Medeiros 06 February 2013 (has links)
A Agência Nacional de Vigilância Sanitária (ANVISA) não exige a realização de ensaios de bioequivalência utilizando métodos enantiosseletivos de quantificação de fármacos para o registro de medicamentos genéricos ou similares contendo fármacos racêmicos. Porém, existe a possibilidade das diferenças de concentrações plasmáticas dos enantiômeros entre o medicamento referência e os genéricos e/ou similares comercializados no Brasil serem maiores que as estabelecidas pelos limites de bioequivalência. Esse estudo teve a finalidade de investigar a influência da velocidade de liberação do fármaco metoprolol, a partir da forma farmacêutica, sobre o processo de absorção do fármaco total e de seus enantiômeros por meio da avaliação das concentrações plasmáticas de metoprolol total, (S)-metoprolol e (R)-metoprolol, e da relação entre as concentrações dos enantiômeros (S/R) após a administração oral de medicamentos contendo mistura racêmica deste fármaco. Para isso, foi realizado ensaio de biodisponibilidade in vivo, em um grupo de 20 voluntários saudáveis, de acordo com procedimentos éticos estabelecidos internacionalmente. Foram empregados três esquemas de administração do metoprolol, com a finalidade de simular diferentes velocidades de liberação do fármaco a partir da forma farmacêutica, na Fase 1 foi administrado uma dose única de 100 mg de metoprolol em solução, na Fase 2 e Fase 3 essa mesma dose foi particionada em duas e cinco administrações, respectivamente, com intervalo de 30 minutos entre elas. Foram coletadas amostras de sangue, e estas foram analisadas utilizando método convencional e método quiral para quantificação do metoprolol total e seus enantiômeros, respectivamente, utilizando cromatografia líquida de alta eficiência, com detector de fluorescência. Os parâmetros farmacocinéticos de ASC0-t, Cmáx e Tmáx foram utilizados para comparação entre as três velocidades de liberação do fármaco a partir da forma farmacêutica. A análise farmacocinética para o fámaco (R,S) metoprolol e seus enantiômeros e a comparação entre seus parâmetros farmacocinéticos obtidos após administração oral do metoprolol, indicam uma cinética enantioseletiva para o metoprolol, que pode ter ocorrido devido a uma biotransformação pré-sistêmica dose-dependente, ou a uma inibição do metabolismo do (S)-metoprolol pela forma (R)-metoprolol. / ANVISA, brazilian regulatory agency for drug products, does not require the use of enantioselective bioanalytical methods in bioequivalence assays of generic and similar drug products containing racemic drugs. Therefore, it is possible that two formulations are bioequivalent based on plasmatic concentration of total drug, but are not bioequivalent on the basis of the comparison of the data of the stereoisomers. The objective of this study was to investigate the influence of the release rate of metoprolol from the dosage form on its absorption process and on its enantiomers\' absorption process by measuring plasmatic concentrations of total metoprolol, (S)-metoprolol and (R)-metoprolol after oral administration of drug products containing racemic metoprolol. An in vivo bioavailability study was conducted in a group of 20 healthy volunteers, according to national and international guidelines for biomedical research, in which the administration rate of metoprolol was varied. In Phase 1 a single dose of 100 mg metoprolol was administered in solution, in Phase 2 and Phase 3 the same dose was partitioned into two and five administrations, respectively, with an interval of 30 minutes between them. Blood samples were collected, and these were analyzed using the conventional method and chiral method for quantification of (R,S)-metoprolol and for its enantiomers, using high performance liquid chromatography with fluorescence detection. The pharmacokinetic parameters AUC0-t, Cmax and Tmax were used for comparisons between three different drug release rates. Pharmacokinetic analysis for (R, S) metoprolol and its enantiomers and comparison of their pharmacokinetic parameters obtained after oral administration of metoprolol, to indicate an enantioselective kinetic, which may be due to a biotransformation pre-systemic dose dependent or the inhibition of metabolism of the (S)-form for metoprolol (R)-metoprolol.
62

L'intrigant couplage radicalaire stéréosélectif médié par la protéine dirigeante AtDIR6 / A stereoselective radical coupling mediated by the dirigent protein AtDIR6

Modolo, Camille 20 December 2017 (has links)
Dans la famille des protéines dirigeantes, AtDIR6, oriente le couplage de radicaux phénoxyles afin de former un lignane optiquement pur : le (-)-pinorésinol. Comme de nombreux lignanes, le pinorésinol est un produit d’intérêt avec des propriétés anti-cancéreuse et anti-fongique. Avec pour objectif à long terme de mettre au point de nouveaux biocatalyseurs énantiosélectifs, nous nous sommes intéressés au mécanisme d’action d’AtDIR6.Dans un premier temps, la production d’AtDIR6 et les conditions de bioconversion ont été optimisées. L’effet dose-dépendant de la protéine sur la formation du (-)-pinorésinol a été confirmé. Les études spectroscopiques entreprises afin de préciser la nature du « substrat » pris en charge par AtDIR6 ont permis de confirmer que l’alcool coniférylique est un mauvais substrat. De plus, par RPE nous avons pu mettre en évidence pour la première fois qu’AtDIR6 augmente la durée de vie de la forme radicalaire de l’AC. Par ailleurs, le greffage covalent d’une sonde radicalaire sur AtDIR6 nous a permis de marquer une tyrosine localisée dans la cavité. Avec AtDIR6 marquée la régiosélectivité de la réaction est affectée. Par ailleurs, la reconnaissance de molécules substrats par AtDIR6 semble être naturellement limitée à un motif 2-methoxy-phénol. Nous montrons pour la première fois que le motif propényle peut être modifié comme en témoigne les produits de bioconversion de l’acétate d’AC pour lesquels une régiosélectivité dépendante de la présence d’AtDIR6 est observée. L’ensemble de nos résultats ouvre des perspectives dans l’utilisation de protéines dirigeantes pour la formation contrôlée de nouveaux produits de couplage. / The family of the leading proteins gathers proteins widely spread within the plant world. In this family, AtDIR6, one of the first characterized proteins, directs the coupling of phenoxyl radicals to form an optically pure lignan: the (-)-pinoresinol. Like many lignans, pinoresinol is a product of interest with anti-cancer and anti-fungal properties. With the long-term goal of developing new enantioselective biocatalysts, we are interested in the mechanism of action of AtDIR6.At first, AtDIR6 production and bioconversion conditions were optimized. The dose-dependent effect of the protein on (-)-pinoresinol formation was confirmed. Spectroscopic studies undertaken to clarify the nature of the "substrate" accommodated by AtDIR6 have confirmed that coniferyl alcohol is a poor substrate. Furthermore, by EPR we have been able to highlight for the first time that AtDIR6 increases the life of the radical form of coniferyl alcohol. Moreover, the covalent grafting of a radical probe on AtDIR6 allowed us to tag a tyrosine located in the cavity. With the tagged protein the regioselectivity of the reaction is affected. On the other hand, the recognition of substrate molecules by AtDIR6 seems to be naturally limited to AC or its radical, apparently recognized because of the 2-methoxyphenol motif. We show for the first time that the propenyl unit can be modified as evidenced by the bioconversion products of AC acetate for which a regioselectivity dependent on the presence of AtDIR6 is observed. All of our results open up prospects for the use of dirigent proteins for the controlled formation of new coupling products.
63

Asymmetric Synthesis of C-Glycosylated Amino Acids : Incorporation in Collagen Glycopeptides and Evaluation in a Model for Rheumatoid Arthritis

Gustafsson, Tomas January 2005 (has links)
<p>This thesis describes stereoselective syntheses of four amino acids, three of which are C-glycosidic analogues of glycosylated amino acids. The overall goal of the project was to probe the interactions between MHC molecules, glycopeptide antigens and T cell receptors, that are essential for development of collagen induced arthritis. Collagen induced arthritis is a frequently used mouse model for rheumatoid arthritis, an autoimmune disease that attacks joint cartilage and leads to a painful and eventually crippling condition.</p><p>The thesis is based on four studies. The first study describes the synthesis of hydroxylysine, an amino acid that is found in collagen and is an important constituent of the glycopeptide proposed as an antigen in collagen induced arthritis. During the synthesis of hydroxylysine some new insight into the mechanism of the reductive opening of <i>p</i>-methoxybenzylidene acetals was obtained.</p><p>The remaining three studies deals with the synthesis of C-glycosidic analogues of glycosylated amino acids, hydroxy norvaline, threonine and hydroxylysine.The synthesis of each amino acid required control of several stereogenic centra and utilizes a variety of approaches such as use of stereoselective reactions, chiral auxilaries, chiral templates and asymmetric catalysis.</p><p>The C-glycosidic analogues of galactosylated hydroxynorvaline and hydroxylysine were incorporated in glycopeptides from type II collagen and evaluated in T cell response assays. It was found that the T cells were stimulated by the C-glycopeptides, but that higher concentrations were required than for the native O-glycopeptide</p>
64

Asymmetric Synthesis of C-Glycosylated Amino Acids : Incorporation in Collagen Glycopeptides and Evaluation in a Model for Rheumatoid Arthritis

Gustafsson, Tomas January 2005 (has links)
This thesis describes stereoselective syntheses of four amino acids, three of which are C-glycosidic analogues of glycosylated amino acids. The overall goal of the project was to probe the interactions between MHC molecules, glycopeptide antigens and T cell receptors, that are essential for development of collagen induced arthritis. Collagen induced arthritis is a frequently used mouse model for rheumatoid arthritis, an autoimmune disease that attacks joint cartilage and leads to a painful and eventually crippling condition. The thesis is based on four studies. The first study describes the synthesis of hydroxylysine, an amino acid that is found in collagen and is an important constituent of the glycopeptide proposed as an antigen in collagen induced arthritis. During the synthesis of hydroxylysine some new insight into the mechanism of the reductive opening of p-methoxybenzylidene acetals was obtained. The remaining three studies deals with the synthesis of C-glycosidic analogues of glycosylated amino acids, hydroxy norvaline, threonine and hydroxylysine.The synthesis of each amino acid required control of several stereogenic centra and utilizes a variety of approaches such as use of stereoselective reactions, chiral auxilaries, chiral templates and asymmetric catalysis. The C-glycosidic analogues of galactosylated hydroxynorvaline and hydroxylysine were incorporated in glycopeptides from type II collagen and evaluated in T cell response assays. It was found that the T cells were stimulated by the C-glycopeptides, but that higher concentrations were required than for the native O-glycopeptide
65

Stereoselective Synthesis of Amino Alcohols : Applications to Natural Product Synthesis

Torssell, Staffan January 2007 (has links)
This thesis is divided into four separate parts with amino alcohols as the common feature. The first part of the thesis describes the development of an efficient three-component approach to the synthesis of α-hydroxy-β-amino esters. Utilizing a highly diastereoselective Rh(II)-catalyzed 1,3-dipolar cycloaddition of carbonyl ylides to various aldimines, syn-α-hydroxy-β-amino esters are formed in high yields and excellent diastereoselectivities. An asymmetric version was also developed by employing chiral α-methylbenzyl imines as dipolarophiles yielding enantiomerically pure syn-α-hydroxy-β-amino esters. This methodology was also applied on a short asymmetric synthesis of the paclitaxel side-chain as well as in an asymmetric synthetic approach towards the proteasome inhibitor omuralide. Furthermore, the use of chiral Rh(II) carboxylates furnishes the syn-α-hydroxy-β-amino esters in moderate enantioselectivity (er up to 82:18), which indicates that the reaction proceeds via a metal-associated carbonyl ylide. The second part describes the development of a 1,3-dipolar cycloaddition reaction of azomethine ylides to aldehydes for the synthesis of α-amino-β-hydroxy esters. Different methods for the generation of the ylides, including Vedejs’ oxazole methology and an Ag(I)/phosphine-catalyzed approach have been evaluated. The best results were obtained with the Ag(I)/phosphine approach, which yielded the desired α-amino-β-hydroxy ester in 68% yield and 3.4:1 syn:anti-selectivity. The last two parts deals with the total synthesis of the amino alcohol-containing natural products D-erythro-sphingosine and (−)-stemoamide. The key transformation in the sphingosine synthesis is a cross-metathesis reaction for the assembly of the polar head group and the aliphatic chain. In the stemoamide synthesis, the key feature is an iodoboration/Negishi/RCM-sequence for the construction of the β,γ-unsaturated azepine core of stemoamide followed by a stereoselective bromolactonization/1,4-reduction strategy for the installation of the requisite C8-C9 trans-stereochemistry. / QC 20100820
66

Stereoselective Nucleophilic Additions to α-Amino Aldehydes: Application to Natural Product Synthesis

Restorp, Per January 2006 (has links)
This thesis deals with the development and application of new synthetic methodology for stereo- or regioselective construction of carbon-carbon bonds in organic synthesis. The first part of this thesis describes the development of a divergent protocol for stereoselective synthesis of chiral aminodiols by employing Mukaiyama aldol additions to syn- and anti-α-amino-β-silyloxy aldehydes. The stereoselectivity of the nucleophilic attack is governed by either chelation to the α-amino moiety or by nucleophilic attack in the Felkin-Anh sense. This study is also directed towards the elucidation of the factors that dictate aldehyde π-facial selectivity in substrate-controlled nucleophilic additions to these and similar systems. In the second part, a highly stereoselective [3 + 2]-annulation reaction of N-Ts-α-amino aldehydes and 1,3-bis(silyl)propenes for stereoselective construction of densely functionalized pyrrolidines is presented. In addition, this methodology is also implemented as a keystep in a synthetic approach towards the polyhydroxylated pyrrolidine and pyrrolizidine alkaloids DGDP and (+)-alexine from a common late pyrrolidine intermediate. Finally, a divergent protocol for regioselective opening of vinyl epoxides using alkyne nucleophiles is described, in which the regioselectivity of the nucleophilic attack is controlled by the choice of reaction conditions. The regioselectivities of the SN2 and SN2’ processes are, however, significantly influenced by the nature of the alkyne substituents and the best results are obtained using ethoxyacetylene. The SN2 opening of vinyl epoxides with ethoxyacetylene as nucleophile is also shown to provide a straightforward entry to functionalized γ-butyrolactones. / QC 20100917
67

Synthesis of Heterocyclic Chiral Diamines and Use of Diamine-based Chiral Guanidines to Determine Enantiopurity of Amino Acids

Mui, Leo 12 January 2011 (has links)
The chiral vicinal diamine moiety is “privileged” and is widely found in catalysts and bio-active compounds. A series of seven chiral vicinal diamines with heterocyclic substituents have been synthesized with great enantiospecificity via the resonance assisted hydrogen bond driven diaza-Cope rearrangement reaction using 1,2-bis(2-hydroxyphenyl)-1,2-diaminoethane and heterocyclic aldehydes as starting materials. This thesis will also discuss the development of a new guanidine-based chiral shift rea-gent for determining the enantiopurity and the absolute configuration of α-amino acids by proton nuclear magnetic resonance (1H NMR) spectroscopy. The chiral shift reagent is easily synthesized from the commercially-available 1,2-diphenyl-1,2-diaminoethane. This method is advantageous over many previously described procedures for determining amino acid enantiopurity as it does not require prior derivatization of the analyte.
68

Synthesis of Heterocyclic Chiral Diamines and Use of Diamine-based Chiral Guanidines to Determine Enantiopurity of Amino Acids

Mui, Leo 12 January 2011 (has links)
The chiral vicinal diamine moiety is “privileged” and is widely found in catalysts and bio-active compounds. A series of seven chiral vicinal diamines with heterocyclic substituents have been synthesized with great enantiospecificity via the resonance assisted hydrogen bond driven diaza-Cope rearrangement reaction using 1,2-bis(2-hydroxyphenyl)-1,2-diaminoethane and heterocyclic aldehydes as starting materials. This thesis will also discuss the development of a new guanidine-based chiral shift rea-gent for determining the enantiopurity and the absolute configuration of α-amino acids by proton nuclear magnetic resonance (1H NMR) spectroscopy. The chiral shift reagent is easily synthesized from the commercially-available 1,2-diphenyl-1,2-diaminoethane. This method is advantageous over many previously described procedures for determining amino acid enantiopurity as it does not require prior derivatization of the analyte.
69

Técnicas de microextração aplicadas à análise estereosseletiva do ibuprofeno, da hidroxicloroquina e de seus metabólitos em urina / Microextraction techniques applied to the stereoselective analysis of ibuprofen, hydroxychloroquine and their metabolites in human urine.

Anderson Rodrigo Moraes de Oliveira 21 June 2007 (has links)
A análise estereosseletiva tem um lugar de destaque em várias áreas e, dentre elas, a farmacêutica, pois diversos fármacos quirais são comercializados como misturas racêmicas. A análise estereosseletiva empregando a cromatografia líquida de alta eficiência e a eletroforese capilar é prática e bastante eficaz para aplicações que envolvem a determinação de enantiômeros ao nível de traços em matrizes complexas, como por exemplo, em estudos de disposição cinética. Entretanto, devido à complexidade das matrizes biológicas, há necessidade da preparação da amostra antes de sua análise. Entre as diversas técnicas existentes, as mais utilizadas são a extração líquido-líquido e a extração em fase sólida. Contudo, essas técnicas apresentam algumas desvantagens,sendo a principal delas o uso de grandes quantidades de solventes. Portanto, técnicas que requerem pouco ou nenhum consumo de solventes orgânicos são bastante desejáveis. Entre essas técnicas destacam-se a microextração em fase sólida (SPME) e a microextração em fase líquida (LPME). Essas técnicas relativamente recentes têm como vantagens a utilização de quantidades mínimas de solventes orgânicos, o alto poder de concentração, a remoção dos interferentes da matriz biológica e a simplicidade de automação. Nesse trabalho propusemos a utilização da SPME e LPME como técnicas de preparação de amostras de urina, visando o desenvolvimento de métodos estereosseletivos com detectabilidade e seletividade adequadas para aplicação em estudos posteriores de disposição cinética. A SPME foi empregada para análise estereosseletiva do ibuprofeno e de seus principais metabólitos, carboxiibuprofeno e 2-hidroxiibuprofeno e da hidroxicloroquina e seus principais metabólitos, enquanto que a LPME foi usada para a análise estereosseletiva da hidroxicloroquina e seus metabólitos. Inicialmente, foi realizada a otimização da separação dos fármacos e metabólitos em diversas colunas quirais,a otimização da separação da hidroxicloroquina e seus metabólitos por eletroforese capilar e,em seguida, a otimização dos procedimentos de extração e a validação dos métodos desenvolvidos. Utilizando a coluna Chiralpak AD-RH® e fase móvel composta por solução de ácido fosfórico 1 mol L-1 pH 3 : metanol (75 : 25, v/v), foi validado um método para análise enantiosseletiva do ibuprofeno em urina. A SPME foi empregada para extração do ibuprofeno das amostras de urina utilizando a fibra PDMS-DVB 60 6;m. O método mostrou ser linear na faixa de concentração de 0,25 a 25 &#956;g mL–1 para cada enantiômero. Para a análise do 2-hidroxiibuprofeno e carboxiibuprofeno, foi utilizada a coluna Chiralpak AS® e fase móvel composta por hexano: isopropanol (94 : 6, v/v) + 0,05% de ácido trifluoracético. A extração desses metabólitos foi feita empregando a fibra de CW-TPR 50 µm. O método mostrou ser linear na faixa de concentração de 5 a 50 µg mL -1. Já para a análise da hidroxicloroquina e seus principais metabólitos, DHCQ e DCQ, foi utilizada a coluna Chiralcel OD-H® e fase móvel composta por hexano : etanol : metanol (96 : 2 : 2, v/v/v) + 0,2% de dietilamina. A extração desses metabólitos foi feita empregando a fibra de PDMSDVB 60 &#956;m. O método mostrou ser linear na faixa de concentração de 50 a 1000 ng mL -1para HCQ e 42 - 416 ng mL-1 para os metabólitos. A microextração em fase líquida foi avaliada na análise da hidroxicloroquina e seus metabólitos, BDCQ, DHCQ e DCQ e separação por eletroforese capilar. Para tanto foi utilizado um capilar de sílica fundida nãorecoberto com um comprimento efetivo de 42 cm, e 30 mmol L-1 de HP-b-CD + 1% de CD-b- sulfatada dissolvida em tampão tris(hidroxiaminometano) 100 mmol L-1 pH 9 como tampão de análise. O método mostrou ser linear na faixa de concentração de 10 - 1000 ng mL-1 para HCQ e 21-333 ng mL-1 para os metabólitos. Obteve-se precisão com coeficientes de variação inferiores a 15% e exatidão com erros relativos menores que 15% para todos os métodos desenvolvidos. Após validação, os métodos foram empregados na determinação da quantidade excretada acumulada do do ibuprofeno, da hidroxicloroquina e de seus metabólitos após administração de de rac-ibuprofeno e rac-hidroxicloroquina a voluntários sadios. Em suma, as duas técnicas foram eficientes na extração dos fármacos e metabólitos estudados. A SPME mostrou ser uma técnica de mais fácil manuseio, porém com baixos valores de recuperação. Por outro lado, a LPME apresentou valores de recuperação maiores, porém o manuseio do sistema de extração foi mais difícil, necessitando de um tempo maior para o domínio da técnica. / The stereoselective analysis has been standing out in several areas, and it is mainly present in the pharmaceutical industry, since many drugs are marketed as racemic mixtures. The stereoselective analysis employing high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) is very useful for the determination of enantiomers at very low concentrations, as the ones found in biological matrices, for instance, in pharmacokinetic studies. The first step in the analysis of drugs in biological fluids is the extraction procedure. The most common extraction procedures employed are liquid-liquid extraction and solidphase extraction. These techniques show several drawbacks, such as the high amount of organic solvent consumed. So, based on this fact, techniques that consume small amounts of organic solvents are desirable. Among these techniques, solid-phase microextraction (SPME) and liquid-phase microextraction (LPME) have been stood out. The main advantages of these techniques are the small amount of organic solvent consumed and its high capacity in drug concentration. In this work, our purpose was to employ the SPME and the LPME as sample preparation techniques to develop stereoselective methods to be further applied in pharmacokinetic studies. SPME was employed for the stereoselective analysis of ibuprofen, hydroxychloroquine and their major metabolites.On the other hand,LPME was employed only for the enantioselective analysis of hydroxychloroquine and its metabolites. The first step was the separation optimization of the drugs and their metabolites by HPLC using several chiral columns, and the separation optimization of hydroxychloroquine and its metabolites by CE. Next, the extraction optimizations and method validations were performed. The enantioselective analysis of ibuprofen in human urine was carried out in the Chiralpak AD-RH® column, using methanol-pH 3.0 phosphoric acid solution (75 : 25 v/v) as mobile phase. The method was linear over the 0.5 - 25 µg mL-1 concentration range for both enantiomers. The fiber used in this method was PDMS-DVB 60 µm.The analysis of 2-hydroxyibuprofen and carboxyibuprofen was performed on a Chiralpak AS® column using hexane:isopropanol (95 : 5 v/v) plus 0.05% trifluoroacetic acid as the mobile phase. The method was linear over the 5 - 50 µg mL-1 concentration range. To perform the extractions, a CW-TPR 50 µm coated fiber was employed. The analysis of hydroxychloroquine and its major metabolites (DCQ and DHCQ) was done on a Chiralcel OD-H® column using hexane-methanol-ethanol (96 : 2 : 2, v/v/v) plus 0.2% diethylamine as mobile phase. The extraction was performed using a PDMS-DVB 60 µm coated fiber. The method was linear over the range of 50 - 1000 ng mL-1 for HCQ enantiomers and over the range of 42 - 416 ng mL-1 for DCQ and DHCQ enantiomers. LPME and CE were applied for the chiral determination of hydroxychloroquine and its metabolites (DCQ, DHCQ, BDCQ) in human urine. The electrophoretic separations were carried out in 100 mmol L-1tris(hydroxymethyl)aminomethane buffer (pH adjusted to 9.0 with phosphoric acid) containing 1% (w/v) S-b-CD and 30 mg mL-1 HP-?-CD, with a constant voltage of +18 kV. The method was linear over the concentration range of 10-1000 ng mL -1 for each HCQ stereoisomer and 21-333 ng mL -1 for each metabolite stereoisomer. Within-day and between-day assay precision and accuracy for all described methods were lower than 15%. The developed methods were applied for the determination of the cumulative urinary excretion of ibuprofen metabolites and hydroxychloroquine and its metabolites after oral administration of racibuprofen and rac-hydroxychloroquine to health volunteers. Comparing the techniques, both SPME and LPME were efficient to extract the drugs and their metabolites from human urine. iv SPME showed to be an easier technique to handle, however, the drug amount recovered by this technique was too small. On the contrary, LPME was a more difficulty technique to be handled, but better recovery values were obtained with this technique.
70

Nanosondes épigénétiques / Epigenetic nanoprobes

Bahhaj, Fatima El 30 October 2014 (has links)
Les cibles épigénétiques telles que les histones désacétylases (HDAC) sont étudiées comme nouveaux traitements anticancéreux, leur fonctionnement anormal étant associée aux processus cancéreux. De nombreux inhibiteurs de ces enzymes sont apparus tel que le SAHA ou le CI-994. Notre laboratoire a développé un nouvel analogue de la trichostatine A appelé NODH. Malgré leur activité anticancéreuse in vitro prometteuse, ces inhibiteurs souffrent de leur manque de solubilité, d'effets toxiques et de leur rapide métabolisation par l'organisme. Afin de pallier ces limitations, ces iHDAC peuvent être conjugués à des vecteurs capables de les transporter dans l'organisme et de les libérer une fois la cible tumorale atteinte. Ce travail de thèse a consisté dans un premier temps à développer des prodrogues acido-sensibles capable de libérer la substance active après endocytose par les cellules. Ces systèmes ont été appliqués aux trois iHDAC SAHA, CI-994 et NODH. Les prodrogues développées ont ensuite été accrochées sur des nanoparticules polymériques connues pour leur biocompatibilité et leur accumulation dans les tumeurs grâce à l'effet EPR. L'activité anticancéreuse de certaines nanoparticules a été validée par des tests in vitro et in vivo. Un deuxième travail a été entrepris concernant la préparation de prodrogues fluorescentes pH labiles capables de libérer la substance active et de moduler la fluorescence par la variation du pH. La dernière partie de ce travail a été consacrée à la mise au point d'une nouvelle méthode de synthèse par voie superacide potentiellement stéréosélective de benzofuranones nécessaires à la préparation d'analogues de NODH. / Epigenetic targets like histone deacetylases (HDAC) are studied as new anticancer treatments, their dysfunctioning being associated to cancer mechanisms. Several epigenetic target inhibitors have been developed like SAHA or CI-994. Our group has developed a new trichostatin A analogue called NODH. Despite their promising in vitro anticancer effect, these inhibitors suffer from lack of solubility, toxic effects and rapid clearance. These constrains make the HDACi good candidates for ligation to vectors able to carry them in the body and to release them when the tumor is reached. The first part of this thesis work has focused on the development of acid sensitive prodrugs able to release an active substance after cellular internalization by endocytosis. These systems were applied to three HDACi SAHA, CI-994 and NODH. These prodrugs were then conjugated to polymeric nanoparticles known for their biocompatibility and their accumulation in tumors exploiting the EPR effect. The anticancer activity of some nanoparticles has been validated by in vitro and in vivo tests. The second part of this work was carried out in order to prepare pH sensitive fluorescent prodrugs able to release the active molecule and to modulate the fluorescent effect by pH changes. The last part of this work was dedicated for the development of a new synthesis in suparacid potentially stereoselective of several benzofuranones required for the preparation of NODH analogs.

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