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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

Evaluation von Gallensäuren als Biomarker für Lebertoxizität in der präklinischen Arzneimittelentwicklung / Evaluation of Bile acids as Biomarkers for Liver Toxicity in Preclinical Drug Development

Slopianka, Markus January 2020 (has links) (PDF)
Die Detektion Arzneimittel-induzierter Leberschädigung (engl. DILI – Drug induced liver injury) stellt eine Herausforderung in der präklinischen Entwicklung von Arzneistoffen dar. Die zur Verfügung stehenden konventionellen klinisch-chemischen Marker, wie Alanin-Aminotransferase (ALAT), Aspartat-Aminotransferase (ASAT) und Alkalische Phosphatase (APh), zeigen z. B. bei minimaler bis leichter Leberpathologie keine Veränderungen im Serum an und besitzen somit nur eine geringe Sensitivität für den frühzeitigen Nachweis einer Lebertoxizität. Des Weiteren besitzen klinisch-chemische Serummarker gleichzeitig eine geringe Spezifität und sind somit für die Differenzierung unterschiedlicher Lebertoxizitäten nur limitiert geeignet. Neben den beschriebenen diagnostischen Herausforderungen können u. a. auch histopathologische Befunde in der Leber, ohne eine Veränderung der klinisch-chemischen Serummarker auftreten und umgekehrt. Die Histopathologie ist als Goldstandard zwar spezifisch, als invasive Technik für eine Verlaufskontrolle in toxikologischen und klinischen Studien aber ungeeignet. In den vergangenen Jahren lieferten Studien zum Gallensäure-Profiling mittels Flüssigkeitschromatographie-Tandem-Massenspektrometrie (LC-MS/MS) mit Modellsubstanzen, die unterschiedliche Formen einer Lebertoxizität in Ratten induzierten Hinweise, dass individuelle Gallensäuren ein diagnostisches Potential für die Bewertung einer Leberschädigung besitzen. Ziel dieser Arbeit ist es, dass Gallensäure-Profiling in die vorgeschriebene Diagnostik der Lebertoxizität in der präklinischen Arzneimittelentwicklung zu implementieren und zu bewerten, ob diese Marker einen wertvollen Beitrag zur Charakterisierung einer Lebertoxizität leisten können. Hierzu wurde eine quantitative LC-MS/MS-Methode etabliert und validiert, die es ermöglicht, 20 verschiedene endogene Gallensäuren in Ratten zu analysieren. Die quantitative Analytik ermöglichte eine selektive Bestimmung von primären, konjugierten und sekundären Gallensäuren. Für die Quantifizierung der individuellen Gallensäuren wurden 2 MRM-Übergänge bestimmt. Zur Bestimmung des Arbeitsbereiches wurden 20 Referenzstandards von Gallensäuren verwendet. Eine Kalibrierung mit sieben Kalibrierpunkten in aufsteigender Konzentration wurde für die Bestimmung der endogenen Konzentrationen genutzt. Zur Kompensation des Matrixeffektes wurden 10 isotopenmarkierte interne Standards in die Analytik eingefügt. Die Reproduzierbarkeit laufender Messungen wurde durch eingefügte Qualitätskontrollen (QCs) in drei verschiedenen Konzentrationsbereichen überwacht. Es wurde ein Gallensäure-Profiling mittels LC-MS/MS im Plasma und Lebergewebe von Ratten, die mit verschiedenen Arzneimitteln behandelt wurden, durchgeführt. Histopathologische Zusammenfassung Untersuchungen konnten aufzeigen, dass sich in den Lebern von männlichen Ratten, die mit dem Arzneimittel Amitriptylin über 14 Tage behandelt wurden, eine makrovesikuläre Steatose in der Leber manifestierte. Die klassischen Serummarker, wie ALAT, ASAT und Gamma-Glutamyltransferase (γGT), konnten diese Art des Leberschadens nicht detektieren. Dagegen erhöhten sich die Konzentrationen Glycin-konjugierter Gallensäuren mit parallel absinkenden Konzentrationen von Taurin-konjugierten Gallensäuren im Lebergewebe behandelter Ratten. Gleichzeitig ergaben sich signifikant erhöhte Konzentrationen der primären Gallensäuren CA und CDCA im Plasma behandelter Ratten. Andere Gallensäure-Profile konnten nach einer Methapyrilen-induzierten Leberzellnekrose mit hepatobiliärer Schädigung beobachtet werden. Nach einer 14-tägigen Behandlungsphase mit 80 mg/kg KG Methapyrilen, erhöhten sich die Konzentrationen von 11 Gallensäuren im Lebergewebe behandelter Tiere. Gleichzeitig stiegen die Konzentrationen von allen 20 individuellen Gallensäuren im Plasma behandelter Ratten an. Zusätzlich zur quantitativen Analyse von Gallensäuren mittels LC-MS/MS wurde die Expression von Genen der Gallensäure-Biosynthese, des Gallensäure-Transports und die Regulation der Gallensäure-Homöostase mittels Multiplex-Analyse untersucht. Die erhöhte Expression von Genen für Efflux-Transporter der Multidrug Resistance-Related Protein (MRP)-Familie deutet auf einen gesteigerten Abtransport von Gallensäuren ins Blut hin und korrespondierte mit erhöhten Gallensäure-Konzentrationen im Plasma der behandelten Ratten. Des Weiteren wurden die Erkenntnisse der Gallensäure-Profile aus den tierexperimentellen Studien als Grundlage genutzt, um Arzneimittel-induzierte Lebertoxizität auf ein zellbiologisches In-vitro-System zu übertragen. Es wurden In-vitro-Experimente mit primären Rattenhepatozyten zwischen zwei Kollagenmatrices (Sandwich-Kultivierung) durchgeführt. Dieses etablierte System wird u. a. für Untersuchungen an hepatobiliären Transportsystemen (z. B. Bile Salt Export Pump, BSEP) genutzt. Das Gallensäure-Profiling in den Zellkulturüberständen belegt, dass die primären Hepatozyten konjugierte Gallensäuren bilden, dass sie bei einer Inkubation mit primären Gallensäuren diese verstoffwechseln und dadurch, neben den bereits vorhandenen Gallensäuren, weitere konjugierte Gallensäuren produzieren. Eine Exposition mit den Hepatotoxinen Troglitazon und Methapyrilen führte zu Veränderungen in der Gallensäure-Homöostase der Hepatozyten. In den In-vivo-Experimenten wurde eine Methapyrilen-induzierte Nekrose mit hepatobiliärer Schädigung in den behandelten Ratten festgestellt. Bei der Behandlung mit Methapyrilen ergaben sich starke Konzentrationsanstiege der Gallensäuren im Plasma (u. a. von GCA und TCA), die mit den histopathologischen Befunden korrelierten. Anhand dieser Daten und der Zusammenfassung pharmakokinetischen Eigenschaften von Methapyrilen wurde ein Studiendesign für Rattenhepatozyten in Sandwich-Kulturen entwickelt, um eine initiale Abschätzung der Konzentrationsveränderungen von Gallensäuren im In-vitro-Testsystem durchzuführen. Ab Tag 8 der Behandlung kam es zu einem erhöhten Anstieg der GCA- und TCA-Konzentrationen im Zellkulturmedium. Daher besitzt das In-vitro-Testsystem möglicherweise das Potential, tierexperimentelle Studien bei der Bewertung einer Hepatotoxizität zu unterstützen oder sogar zu reduzieren. Insgesamt zeigen diese Ergebnisse aus dieser Arbeit, dass Gallensäure-Profiling in männlichen und weiblichen Ratten eine geeignete Methode zur Detektion und Differenzierung von Leberschäden ist. Die Technologie ist flexibel einsetzbar und kann bereits etablierte Testverfahren, wie die Bestimmung von Serummarkern in der Klinischen Chemie und die Histopathologie unterstützen. Damit besitzt das Gallensäure-Profiling das Potential, die Bewertung beim Nachweis und bei der Charakterisierung einer Lebertoxizität im Rahmen der Evaluierung von präklinischen Arzneimittelkandidaten zu verbessern. / Drug-induced liver injury (DILI) remains a significant challenge in preclinical drug development. Nonclinical studies provide an opportunity to correlate the biochemical and morphological findings; however, liver injury is often complex and heterogeneous, confounding the ability to relate biochemical changes to specific, histopathological patterns of liver injury. The diagnostic performance of the available hepatobiliary markers, such as alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT) or alkaline phosphatase (APh), for specific manifestations of liver injury, is often limited and insensitive, e.g. minimal to slight liver pathology might not result in changes to the serum marker. Furthermore, histopathological findings in the liver can occur without there being significant changes in the serum markers and vice versa. Although histopathology is the gold standard, its invasive nature makes it unsuitable for monitoring liver injury in toxicological and non-clinical studies. In recent years, study results of bile acid profiling, using liquid chromatography-tandem mass spectrometry (LC-MS/MS), indicated diagnostic potential regarding the detection of hepatotoxicity. This work aims to establish bile acid profiling in preclinical drug development and to demonstrate that bile acids can provide a valuable contribution to characterizing liver injury in preclinical safety diagnostics. For this purpose, a quantitative LC-MS/MS method was established and validated, in order to analyze 20 different endogenous bile acids in rats. The quantitative analysis enabled the selective determination of primary, conjugated and secondary bile acids. 2 MRM-transitions for qualitative and quantitative analysis were used for the quantification of the individual bile acids. Twenty bile acid reference standards were used for the calibration range. A seven-point calibration, in ascending concentration, was performed to quantify the absolute endogenous bile acid concentrations. Ten isotopically labeled internal standards were employed in the analyses to compensate for matrix effects. The reproducibility of the current measurements was monitored by quality controls (QCs) inserted into three different concentration ranges. Bile acid profiling was performed by LC-MS/MS of plasma and liver tissue of rats that had been treated with different hepatotoxins. The results of the bile acid profiling and histopathological evaluation revealed correlation between bile acid profiles and histopathological graded liver toxicity, e.g., the quantitative analysis and histopathological examination showed that macrovesicular steatosis was induced in the livers of male rats which had been treated with amitriptyline for 14 days. Classic serum markers, such as ALAT, ASAT, and gamma-glutamyltransferase (γGT), were unable to detect this specific manifestation of liver injury. In contrast, the concentrations of glycine-conjugated bile acids Summary increased while there was a parallel decrease in the levels of taurine-conjugated bile acids in the treated rats’ liver tissue. At the same time, there was a significant increase in the concentration of primary bile acids, CA and CDCA, in plasma of treated rats. Different bile acid profiles were observed following methapyrilene-induced liver cell necrosis with hepatobiliary damage. After a 14-day treatment phase with 80 mg/kg body weight methapyrilene, the concentrations of 11 bile acids increased in liver tissue of treated animals. At the same time, the levels of all 20 individual bile acids increased in plasma of treated rats. In addition to the quantitative analysis of bile acids with LC-MS/MS, the expression of specific genes associated with bile acid biosynthesis, and the transport and regulation of bile acid homeostasis, was analyzed using multiplex analysis of targeted mRNA. The increased expression of efflux transporter genes belonging to the multidrug resistance-related protein (MRP) family, indicated an increase in the efflux transport of bile acids into blood, and corresponded to increased bile acid concentrations in the plasma of treated rats. Furthermore, bile acid profiles originated from the animal studies, were used as reference to evaluate bile acid profiles regarding liver toxicity on a liver cell-based biological system. In vitro experiments were performed using primary rat hepatocytes between two collagen matrices (sandwich cultivation). This traditional in vitro model is used to study of hepatobiliary transport alterations (e.g., Bile Salt Export Pump, BSEP). Bile acid profiling of the cell culture supernatants demonstrated that the primary hepatocytes produced conjugated bile acids. Incubation with primary bile acids resulted in an improvement of the in vitro system by producing conjugated bile acids, in addition to those already existed. Exposure to troglitazone and methapyrilene resulted in changes in the hepatocytes’ bile acid homeostasis. In the in vivo experiments, methapyrilene treatment induced necrosis and hepatobiliary damage in the treated rats. There was a substantial increase in the concentration of plasma bile acids in the methapyrilene treatment group (including GCA and TCA), which correlated with the histopathological findings. Based on these data and the pharmacokinetic properties of methapyrilene, a study design was developed that used rat hepatocytes in sandwich cultures to provide an initial estimate of bile acid concentration changes in the in vitro test system. There was an increase in GCA and TCA concentrations in the cell culture medium from day 8 of the methapyrilene treatment. Therefore, the in vitro test system may have the potential to support or even reduce animal studies for evaluating hepatotoxicity. Bile acid profiling in male and female rats is a suitable method for detecting and differentiating liver injury. The technology can be used flexibly and can support already established test procedures, such as the determination of serum markers in clinical chemistry and histopathology. Summary Thus, bile acid profiling has the potential to fill the gap in the detection and characterization of hepatotoxicity, as part of the evaluation of preclinical drug candidates.
2

Avaliação de técnicas cromatográficas acopladas a espectrometria de massas para análise de morfolina em manga / Evaluation of chromatographic techniques coupled to mass spectrometry for morpholine analysis in mango

Souza, Patricia Regina de 15 April 2016 (has links)
A constante preocupação com o aumento do uso de agrotóxicos nas lavouras e os riscos gerados pelos resíduos destes compostos fazem com que os órgãos responsáveis pela fiscalização de alimentos no Brasil controlem a presença dessas substâncias nos produtos que chegam à mesa do consumidor. Atualmente, um dos grandes problemas na produção de alimentos é a utilização de substâncias proibidas em lavouras, muitas das quais não possuem estudos nem limites máximos de resíduos (LMR) estabelecidos, assim como a utilização de substâncias já registradas, mas em quantidades ou métodos de manejo incorretos. Ambos os casos podem resultar em sérios problemas à saúde humana. O objetivo deste estudo foi a avaliação da determinação de morfolina em amostras de manga utilizando técnicas como a Extração em Fase Sólida e a Cromatografia Gasosa acoplada à Espectrometria de Massas (SPE-GC-MS), assim como a Microextração em Sorvente Empacotado e Cromatografia Gasosa acoplada à Espectrometria de Massas (MEPS-GC-MS). Um segundo objetivo deste estudo consistiu em desenvolver, validar e avaliar uma metodologia analítica capaz de identificar quantitativamente a morfolina em amostras de manga por Cromatografia Líquida de Ultra Eficiência acoplada a Espectrometria de Massas em tandem (UHPLC-MS/MS). Para análise por GC-MS fez-se necessária a etapa de derivatização do analito, de forma que o mesmo aumentasse sua volatilidade e diminuísse a polaridade. A comparação entre as técnicas SPE e MEPS não foi possível devido ao efeito de matriz causado pela contaminação do liner e da coluna cromatográfica. Já a metodologia validada por UHPLC-MS/MS seguiu os critérios exigidos pelo Manual de Garantia da Qualidade Analítica, do Ministério da Agricultura Pecuária e Abastecimento (MAPA). O método foi aplicado em mangas de diferentes variedades obtidas no comércio local. Não foram encontrados resíduos de morfolina em nenhuma das amostras investigadas, de acordo com a metodologia proposta. Os resultados apresentados neste trabalho estabelecem metodologias eficientes, rápidas e de baixo custo na determinação de morfolina em amostras de manga. / The recurrent increasing of the use of pesticides on crops and the consequent risks due the exposure to chemical residues have urged the food regulation agencies to control the levels of these substances in products that reach consumer\'s table. A major problem nowadays for the production of food is the use of banned substances in crops and the extrapolation of the limit dosages of substances, which may result in serious problems to human health. Furthermore, many of these substances commonly used in crops still lack substantial information about the maximum residue levels (MRLs). The aim of this study was the evaluation of morpholine levels in mango samples using distinct techniques such as Solid Phase Extraction followed by Gas Chromatography coupled to Mass Spectrometry (SPE-GC-MS) and Microextraction by Packed Sorbent followed by Gas Chromatography Mass Spectrometry (MEPS-GC-MS). Another main goal of this work is the development, validation and evaluation of an analytical methodology to identify and quantitfy the presence of morpholine in mango samples, using Ultra-High Performance Liquid Chromatography coupled to tandem Mass Spectrometry (UHPLC-MS/MS). For the analysis of samples by GC-MS, it was required an initial step of derivatization of the analyte, in order to increase its volatility and reduce polarity. The comparison between SPE and MEPS techniques could not be performed due to matrix effects caused by contamination of the liner and the chromatographic column. On the other hand, the validated methodology for UHPLC-MS/MS presented herein followed all requirements proposed by the Analytical Quality Assurance Manual, accordingly to the Ministry of Agriculture, Livestock and Food Supply from Brazil. This method was applied in mango sample belonging to a wide variety of species found in the city of São Carlos, SP. Nevertheless, no significant levels of morpholine residues were found in any of the samples. In this work, we established a methodology efficient, fast and low cost for the determination of morpholine in mangos.
3

Avaliação de técnicas cromatográficas acopladas a espectrometria de massas para análise de morfolina em manga / Evaluation of chromatographic techniques coupled to mass spectrometry for morpholine analysis in mango

Patricia Regina de Souza 15 April 2016 (has links)
A constante preocupação com o aumento do uso de agrotóxicos nas lavouras e os riscos gerados pelos resíduos destes compostos fazem com que os órgãos responsáveis pela fiscalização de alimentos no Brasil controlem a presença dessas substâncias nos produtos que chegam à mesa do consumidor. Atualmente, um dos grandes problemas na produção de alimentos é a utilização de substâncias proibidas em lavouras, muitas das quais não possuem estudos nem limites máximos de resíduos (LMR) estabelecidos, assim como a utilização de substâncias já registradas, mas em quantidades ou métodos de manejo incorretos. Ambos os casos podem resultar em sérios problemas à saúde humana. O objetivo deste estudo foi a avaliação da determinação de morfolina em amostras de manga utilizando técnicas como a Extração em Fase Sólida e a Cromatografia Gasosa acoplada à Espectrometria de Massas (SPE-GC-MS), assim como a Microextração em Sorvente Empacotado e Cromatografia Gasosa acoplada à Espectrometria de Massas (MEPS-GC-MS). Um segundo objetivo deste estudo consistiu em desenvolver, validar e avaliar uma metodologia analítica capaz de identificar quantitativamente a morfolina em amostras de manga por Cromatografia Líquida de Ultra Eficiência acoplada a Espectrometria de Massas em tandem (UHPLC-MS/MS). Para análise por GC-MS fez-se necessária a etapa de derivatização do analito, de forma que o mesmo aumentasse sua volatilidade e diminuísse a polaridade. A comparação entre as técnicas SPE e MEPS não foi possível devido ao efeito de matriz causado pela contaminação do liner e da coluna cromatográfica. Já a metodologia validada por UHPLC-MS/MS seguiu os critérios exigidos pelo Manual de Garantia da Qualidade Analítica, do Ministério da Agricultura Pecuária e Abastecimento (MAPA). O método foi aplicado em mangas de diferentes variedades obtidas no comércio local. Não foram encontrados resíduos de morfolina em nenhuma das amostras investigadas, de acordo com a metodologia proposta. Os resultados apresentados neste trabalho estabelecem metodologias eficientes, rápidas e de baixo custo na determinação de morfolina em amostras de manga. / The recurrent increasing of the use of pesticides on crops and the consequent risks due the exposure to chemical residues have urged the food regulation agencies to control the levels of these substances in products that reach consumer\'s table. A major problem nowadays for the production of food is the use of banned substances in crops and the extrapolation of the limit dosages of substances, which may result in serious problems to human health. Furthermore, many of these substances commonly used in crops still lack substantial information about the maximum residue levels (MRLs). The aim of this study was the evaluation of morpholine levels in mango samples using distinct techniques such as Solid Phase Extraction followed by Gas Chromatography coupled to Mass Spectrometry (SPE-GC-MS) and Microextraction by Packed Sorbent followed by Gas Chromatography Mass Spectrometry (MEPS-GC-MS). Another main goal of this work is the development, validation and evaluation of an analytical methodology to identify and quantitfy the presence of morpholine in mango samples, using Ultra-High Performance Liquid Chromatography coupled to tandem Mass Spectrometry (UHPLC-MS/MS). For the analysis of samples by GC-MS, it was required an initial step of derivatization of the analyte, in order to increase its volatility and reduce polarity. The comparison between SPE and MEPS techniques could not be performed due to matrix effects caused by contamination of the liner and the chromatographic column. On the other hand, the validated methodology for UHPLC-MS/MS presented herein followed all requirements proposed by the Analytical Quality Assurance Manual, accordingly to the Ministry of Agriculture, Livestock and Food Supply from Brazil. This method was applied in mango sample belonging to a wide variety of species found in the city of São Carlos, SP. Nevertheless, no significant levels of morpholine residues were found in any of the samples. In this work, we established a methodology efficient, fast and low cost for the determination of morpholine in mangos.
4

Contribution à l'étude phytochimique et à la valorisation biologique du latex de Hura crepitans L. / Contribution to the phytochemical study and biological valuation of the latex of Hura crepitans L.

Trinel, Manon 16 November 2018 (has links)
Une collaboration entre les chercheurs du laboratoire Pharma-Dev et de l'Institut de Recherche en Santé Digestive a été mise en place depuis plusieurs années avec pour objectif le criblage thérapeutique de nouvelles molécules naturelles issues de la biodiversité végétale. Dans ce contexte, le travail présenté dans ce manuscrit est consacré à l'étude phytochimique du latex de Hura crepitans L. (Euphorbiaceae) et à la valorisation biologique de ses constituants sur des lignées cancéreuses colorectales humaines. La richesse en structures diterpéniques originales de la famille des Euphorbiaceae et le rôle de ces noyaux structuraux dans l'activation de Protéines Kinases C (PKC) impliquées dans la carcinogenèse colorectale, font de H. crepitans une espèce au potentiel thérapeutique important. Au cours de ce travail, une approche déréplicative par UHPLC-MS/MS a permis de mettre en évidence la présence de cérébrosides et une richesse notable en diterpènes de type daphnane chez H. crepitans. Au total, 33 daphnanes dont 25 nouvelles structures ont été détectées. Le fractionnement du latex a permis l'isolement de 7 daphnanes mono-estérifiés (D1) et de 6 dérivés di-estérifiés. L'évaluation biologique a révélé une activité cytostatique des D1 spécifique sur la lignée cancéreuse Caco-2 comparée à d'autres lignées intestinales normales ou cancéreuses. Cette activité est inhibée par les cérébrosides. Le D1 majoritaire, la huratoxine, a montré une activité cytostatique dès 1 µg/ml et comparativement plus spécifique que le 5-Fluoro-Uracile, cytotoxique utilisé comme référence. De plus, nous avons montré que les effets cytostatiques de la huratoxine et de l'ester de phorbol TPA sont corrélés à la régulation de signaux clés de la carcinogenèse colorectale, GSK3ß et AKT notamment, et à des changements morphologiques. Finalement, nous avons pu identifier une isoenzyme PKC comme cible potentielle de ces composés naturels. / A collaboration between the researchers of the laboratory Pharma-Dev and the Research institute in Digestive Health has been established since several years with as main objective the therapeutic screening of new natural molecules from the plant biodiversity. In this context, the work presented in this manuscript deals with the phytochemical study of the latex of Hura crepitans L. (Euphorbiaceae) and the biological valuation of its constituents on human colorectal cancerous cell lines. The wealth in original diterpene like structures within the family of Euphorbiaceae and the role of these structural cores in the activation of Proteins Kinases C (PKC) involved in the colorectal carcinogenesis, make of H. crepitans a species with a promising therapeutic potential. In the course of this work, a dereplicative approach by UHPLC-MS/MS allowed to highlight the presence of cerebrosides and a notable wealth in daphnane type diterpene in H. crepitans. This led to the annotation of 33 daphnanes including 25 new structures. Therefore, 7 mono-esterified daphnanes (D1) and 6 di-esterified derivatives could be isolated. The biological evaluation revealed, for D1, a specific cytostatic activity on the cancerous cell line Caco-2 when compared to other non-cancerous or cancerous intestinal cell lines. This activity is inhibited by cerebrosides. The main D1, huratoxine, is cytostatic from 1 µg/ml and was showed to be more specific than 5-Fluoro-Uracile, a cytotoxic drug used as reference. Furthermore, we demonstrated that the cytostatic effects of huratoxine and phorbol ester TPA are correlated to the regulation of key signals of the colorectal carcinogenesis, particularly GSK3ß and AKT, and in cells morphological changes. Finally, we were able to identify a PKC isoenzyme as a potential target of these natural products.
5

Etude phytochimique de la variété de rose ‘Jardin de Granville’ : de la caractérisation variétale à la caractérisation moléculaire / Phytochemical study of the rose cultivar ‘Jardin de Granville’ : from variety differenciation to molecular specificities

Riffault Valois, Ludivine 12 December 2014 (has links)
‘Jardin de Granville’ ‘est une variété de rose moderne dédiée à des applications cosmétiques en lien avec ses propriétés intéressantes permettant de lutter contre les mécanismes inflammatoires et oxydants au niveau cutané. L’objectif principal de cette thèse a consisté à établir la cartographie moléculaire de ‘Jardin de Granville’. Pour cela, un procédé standardisé de récolte et d’extraction a été développé afin d’accéder au contenu moléculaire le plus exhaustif possible des différents organes de la plante. Des méthodes complémentaires d’analyse, allant de l’HPTLC, à l’HPLC-DAD-DEDL et jusqu’à l’UHPLC-HRMS, ont été mises en oeuvre pour réaliser les empreintes chromatographiques des extraits et en identifier les principaux constituants. Ces méthodes ont été choisies de plus en plus spécifiques et précises, de façon à apporter une graduation dans le niveau d’informations apportées. Plus de 120 molécules ont pu être caractérisées dans les différents extraits. Le deuxième objectif résidait dans la mise en évidence des marqueurs phytochimiques spécifiques à la variété en comparant ses empreintes moléculaires à celles des deux variétés parents. Deux méthodes de comparaison des profils ont été développées. La première met en jeu des analyses statistiques telles que l’ACP, la CAH et l’ANOVA qui permettent de comparer l’ensemble des extraits. La seconde effectue la soustraction des chromatogrammes d’extrait deux à deux et donne accès à un niveau d’informations plus ciblé. Ces deux approches ont conduit à l’identification de composés différenciant chaque type d’organes ce qui pourra servir d’outils dans la valorisation de certaines parties de la plante. Des marqueurs potentiels plus spécifiques à ‘Jardin de Granville’ ont pu être mis en évidence ce qui démontre la capacité des méthodes développées à différencier le contenu phytochimique de variétés de rose très proches. / The modern rose variety ‘Jardin de Granville’, possesses proven activities against skin cell inflammatory and oxidant mechanisms and is devoted to cosmetic applications. The main goal of this study was to establish the molecular fingerprint of the different organs of ‘Jardin de Granville’. In this way, a standardized process for plant harvesting and sample extraction was developed giving access to the most exhaustive molecular fingerprint possible of the different organs. Several complementary analytical methods were implemented through HPTLC, HPLC-DAD-ELSD and UHPLC-HRMS, enabling to achieve the chromatographic fingerprint of the different organs and to identify the main constituents. These methods were selected to have increasing specificity and accuracy to bring progressive information on the molecule structure. Thus, more than 120 compounds were characterized in the different extracts. The second objective consisted in identifying specific phytochemical markers of the variety by comparing its fingerprint to those obtained from its two rose plant parents. In this way, two approaches were developed. The first one involves statistical analysis like PCA, HAC and ANOVA and allows comparing the whole sample chromatograms. The second approach performs extract chromatogram subtractions two by two and gives more detailed information. Both comparative methods led to the identification of the differential compounds existing between the different organ types which could be used to valuate some plant parts in particular. Some ‘Jardin de Granville’ specific markers were highlighted showing the method capacity to distinguish very close rose varieties, by comparing their molecular content.
6

Desenvolvimento de metodologia por cromatografia líquida de ultra eficiência para determinação de histamina em pescados in natura e em conservas / Development methodology for ultra high performance liquid chromatography for histamine determination fish in fresh and canned

Takemoto, Emy 15 June 2016 (has links)
No Brasil, o consumo de pescado in natura cresce a cada ano e sua ingestão tem sido associada a problemas de saúde, principalmente, surtos de intoxicação alimentar causado pela histamina, podendo representar risco à saúde do consumidor. A histamina pode provocar erupções na pele, náuseas, dor de cabeça, palpitações, vômitos, dores abdominais, distúrbios respiratórios e taquicardia. O Brasil exporta pescado para os principais mercados consumidores e tem enfrentado barreiras comerciais pela exigência de análises de histamina, com a finalidade de assegurar a qualidade do pescado exportado. Assim sendo, foi desenvolvido e validado um método por cromatografia líquida de ultra eficiência (CLUE) para a determinação dos teores de histamina em peixes. O método desenvolvido mostrou ter boa linearidade, seletividade, exatidão e precisão, ser robusto e com os limites de detecção e quantificação determinados de 0,03 µg mL-1 e 0,10 µg mL-1, respectivamente. A metodologia foi aplicada a amostras de pescados (atum e sardinha) in natura e em conservas. Das 12 amostras analisadas de atum in natura somente uma apresentou teor de histamina de 1,07 mg.kg-1, 05 amostras de sardinha in natura apresentaram teores de 26,81, 0,35, 37,25, 9,97 e 0,94 mg kg-1, respectivamente. Nas amostras de atum em conserva, 02 apresentaram teores de 1,30 e 0,13 mg kg-1. Enquanto que, 04 amostras de sardinha em conserva continham teores de histamina de 2,49, 68,96 e 11,66 mg kg-1, e uma das amostras de sardinha em conserva estava com o teor muito acima, cerca de 17 vezes do limite máximo estabelecido pelo MAPA, de 100 mg kg-1 para conservas de sardinha. Essa quantidade de histamina encontrada pode sugerir a ocorrência de uma intoxicação, representando risco à saúde humana. Além disso, foi calculada a incerteza de medição, pois garante uma maior confiabilidade dos resultados analíticos para tomadas de decisões importantes em Vigilância Sanitária e Saúde Pública. / In Brazil, the consumption of fish in nature grows every year and its intake has been linked to health problems, especially food poisoning outbreaks caused by histamine, which may pose a risk to consumer health. Histamine can cause skin rashes, nausea, headache, palpitations, vomiting, abdominal pain, respiratory disorders and tachycardia. Brazil exports fish to the main consumer markets and has faced trade barriers by requiring histamine analysis, in order to ensure the quality of exported fish. Thus, it was a method developed and validated liquid chromatography ultra efficiency (CLUE) for determining histamine levels in fish. The method was proven to have good linearity, selectivity, accuracy and precision and be robust with the limits of detection and quantification of certain 0,03 ug mL-1 and 0.10 ug mL-1, respectively. The methodology was applied to fish samples (tuna and sardines) in fresh and canned. Of the 12 samples analyzed tuna in fresh only one showed histamine content of 1.07 mg.kg-1, 05 sardine in fresh samples showed levels of 26.81, 0.35, 37.25, 9.97 and 0.94 mg kg-1, respectively. In the samples of canned tuna, 02 showed levels of 1.30 and 0.13 mg kg-1. While 04 canned sardines containing histamine concentrations of 2.49, 68.96 and 11.66 mg kg-1, and one sample canned sardine content was much higher, about 17 times higher than the maximum limit established by MAPA, 100 mg kg-1 for canned sardine. This amount of histamine found may suggest the occurrence of intoxication, representing a risk to human health. In addition, the measurement uncertainty was calculated as it ensures a higher reliability of the analytical results for taking important decisions on Health Surveillance and Public Health.
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Vliv stresového faktoru sucha na obsah glykoalkaloidů brambor (Solanum tuberosum L.) / Effect of drought stress factor on glycoalkaloid contents in potato (Solanum tuberosum L.)

Matoušková, Vendula January 2016 (has links)
Potatoes are an important and irreplaceable crop. This kind of crop is very important not only for it is use but also for a nutrition composition. There are also a prominent source of vitamins, minerals and antioxidants. Outside substances beneficial to health and potatoes contain harmful substances. These substances are foreign or naturally occurring, which include toxic glycoalkaloids. Glycoalkaloids are secondary metabolites of plants. Glycoalkaloids in potatoes have protective function it can increase the synthesis for example in case of pest infestations, mechanical damage or in case of to much light and heat. The potatoes were found several glycoalkaloides. Main, which constitutes 95 % of their content, are alpha-chaconine and alpha-solanine. Their toxicity is inhibition of acetylcholinesterase and breaking the cell membranes. The potato tuber is their content is distributed unevenly. The quantity of glycoalkaloids is affected by manny factors as for example place, year, kind, the way how the crops are grown and storage. In Czech Republic the maximum allowed limit of glycoalkaloides in potatoes were made by legislation on 200 mg/kg fresh potato matter. In the commonly grown varieties of the amount is far below the hygienic limit. The methods for isolation of glycoalkaloids in potatoes are mainly chromatographic. The most commonly used HPLC (high performance liquid chromatography). In performed experiment was determined the content of majority glycoalkaloid alpha- chaconinu and alpha-solaninu at four different kinds -Milva, Marabel, Laura and Valfi. Drought stress has been studied for their content, assuming their accumulation in comparison with the other two variants - irrigation watering and drip irrigation. The glycoalkaloides content were messured by the UHPLC/MS/MS. The obtained results concluded that the content of glycoalkaloids is the variety dependent. Drought stress can probably increase their content. In our experiment, it positively did not. Important is the choice of kind in case if expectation a hot and dry year of growing. Kinds Milva and Marabel are very good in these conditions. In the case of general principles for cultivation, storage and cooking, the glykoalkaloids does not vision a risk for the consumer.
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Desenvolvimento de metodologia por cromatografia líquida de ultra eficiência para determinação de histamina em pescados in natura e em conservas / Development methodology for ultra high performance liquid chromatography for histamine determination fish in fresh and canned

Emy Takemoto 15 June 2016 (has links)
No Brasil, o consumo de pescado in natura cresce a cada ano e sua ingestão tem sido associada a problemas de saúde, principalmente, surtos de intoxicação alimentar causado pela histamina, podendo representar risco à saúde do consumidor. A histamina pode provocar erupções na pele, náuseas, dor de cabeça, palpitações, vômitos, dores abdominais, distúrbios respiratórios e taquicardia. O Brasil exporta pescado para os principais mercados consumidores e tem enfrentado barreiras comerciais pela exigência de análises de histamina, com a finalidade de assegurar a qualidade do pescado exportado. Assim sendo, foi desenvolvido e validado um método por cromatografia líquida de ultra eficiência (CLUE) para a determinação dos teores de histamina em peixes. O método desenvolvido mostrou ter boa linearidade, seletividade, exatidão e precisão, ser robusto e com os limites de detecção e quantificação determinados de 0,03 µg mL-1 e 0,10 µg mL-1, respectivamente. A metodologia foi aplicada a amostras de pescados (atum e sardinha) in natura e em conservas. Das 12 amostras analisadas de atum in natura somente uma apresentou teor de histamina de 1,07 mg.kg-1, 05 amostras de sardinha in natura apresentaram teores de 26,81, 0,35, 37,25, 9,97 e 0,94 mg kg-1, respectivamente. Nas amostras de atum em conserva, 02 apresentaram teores de 1,30 e 0,13 mg kg-1. Enquanto que, 04 amostras de sardinha em conserva continham teores de histamina de 2,49, 68,96 e 11,66 mg kg-1, e uma das amostras de sardinha em conserva estava com o teor muito acima, cerca de 17 vezes do limite máximo estabelecido pelo MAPA, de 100 mg kg-1 para conservas de sardinha. Essa quantidade de histamina encontrada pode sugerir a ocorrência de uma intoxicação, representando risco à saúde humana. Além disso, foi calculada a incerteza de medição, pois garante uma maior confiabilidade dos resultados analíticos para tomadas de decisões importantes em Vigilância Sanitária e Saúde Pública. / In Brazil, the consumption of fish in nature grows every year and its intake has been linked to health problems, especially food poisoning outbreaks caused by histamine, which may pose a risk to consumer health. Histamine can cause skin rashes, nausea, headache, palpitations, vomiting, abdominal pain, respiratory disorders and tachycardia. Brazil exports fish to the main consumer markets and has faced trade barriers by requiring histamine analysis, in order to ensure the quality of exported fish. Thus, it was a method developed and validated liquid chromatography ultra efficiency (CLUE) for determining histamine levels in fish. The method was proven to have good linearity, selectivity, accuracy and precision and be robust with the limits of detection and quantification of certain 0,03 ug mL-1 and 0.10 ug mL-1, respectively. The methodology was applied to fish samples (tuna and sardines) in fresh and canned. Of the 12 samples analyzed tuna in fresh only one showed histamine content of 1.07 mg.kg-1, 05 sardine in fresh samples showed levels of 26.81, 0.35, 37.25, 9.97 and 0.94 mg kg-1, respectively. In the samples of canned tuna, 02 showed levels of 1.30 and 0.13 mg kg-1. While 04 canned sardines containing histamine concentrations of 2.49, 68.96 and 11.66 mg kg-1, and one sample canned sardine content was much higher, about 17 times higher than the maximum limit established by MAPA, 100 mg kg-1 for canned sardine. This amount of histamine found may suggest the occurrence of intoxication, representing a risk to human health. In addition, the measurement uncertainty was calculated as it ensures a higher reliability of the analytical results for taking important decisions on Health Surveillance and Public Health.
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Qualitative analysis of LGD-4033 and its metabolites in equine plasma using UHPLC-MS(MS) for doping control purposes

Berndtson, Emma January 2017 (has links)
A new class of drugs has been developed for treatment of muscle and bone mass wasting diseases called non-steroidal selective androgen receptor modulators (SARMs). Because of their positive androgenic effects such as muscle gain, they are desirable as performance enhancers. One of those substances is LGD-4033 (4-[(2R)-2-[(1R)-2,2,2-trifluoro-1-hydroxyethyl]pyrrolidin-1-yl]-2-(trifluoromethyl)- benzonitrile). It has been detected in human samples in routine doping control and another SARM has been detected in an equine blood sample in routine doping control. It is therefore indicated that SARMs need to be screened for in routine testing in equestrian sport. The aim of this project was to identify what metabolites were found in equine plasma after an intra venous administration of LGD-4033 using UHPLC coupled with QToF-MS and determine whether the parent compound or any of its metabolites were most suitable for doping control. With the sample preparation method protein precipitation, six possible metabolites were identified in samples from three horses. Two of the metabolites were identified as phase I-metabolites (monohydroxylated and dihydroxylated). Four of the metabolites were identified as phase II-metabolites, where glucuronidation had occurred. The most suitable species for doping control were determined based on a semi- quantification and were M1a, M2 and M3a.
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Oxidační degradace ticagreloru / Oxidative degradation of ticagrelor

Kvapilová, Pavlína January 2020 (has links)
This thesis deals with the oxidative degradation of the active pharmaceutical substance ticagrelor, which is used together with acetylsalicylic acid as a prevention against atherothrombotic events in adult patients. In this thesis, oxidation was studied both in the traditional way using hydrogen peroxide and the new electrochemical approach. The oxidation was performed with a 3% solution of hydrogen peroxide at 50 řC in various solvents. An electrochemical method for the oxidation of ticagrelor was developed as part of the thesis. This method was then optimized to achieve the highest possible oxidation efficiency. The thesis also investigated the effect of excipients on the oxidation rate. Degradation products were evaluated using the ultra-high performance liquid chromatography. The structures of all the degradation products formed were identified using a QDA mass detector. Key words: UPLC, electrolysis, degradation studies, pharmaceuticals

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