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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.
21

Cytotoxicita vybraných naftochinonů na prostatických buněčných liniích / Cytotoxicity of selected naphthoquinones on prostatic cell cultures

Mondeková, Věra January 2013 (has links)
This master´s thesis discusses cytotoxicity of selected naphthoquinones on prostatic cell cultures. The introductory part is dedicated to general characteristic of naphthoquinones with focus on their cytotoxicity, testing of cytotoxicity and mechanisms of cytotoxicity. This part is followed by chapters about cytotoxicity, characteristics and biological activities of selected naphthoquinones; plumbagin and naphthazarin. The last part of this thesis’ theoretical section speaks about fluorescence microscopy and its use in research of naphthoquinones cytotoxicity. The practical part is dedicated to evaluation of cytotoxical tests’ results and to analysation of pictures of cells obtained by fluorescence microscope. At the end of thesis, all finding are summarized and put in the context.
22

Geminale Dihydroperoxide als Sauerstofftransferreagenzien und Synthesebausteine

Bunge, Alexander 21 December 2011 (has links)
Im Rahmen dieser Dissertation wurden die Herstellung sowie Reaktionen von geminalen Dihydroperoxiden erforscht. Dabei kamen die dargestellten Dihydroperoxide sowohl als Sauerstofftransferreagenz, insbesondere zur enantioselektiven Epoxidation, als auch als Baustein zur Synthese von 1,2,4,5-Tetroxanen zum Einsatz. Es wurde eine in unserem Arbeitskreis gefundene Methode zur Darstellung gem - Dihydroperoxide zunächst hinsichtlich der Reaktionsbedingungen optimiert, um dann eine Vielzahl an Dihydroperoxiden vornehmlich mit dieser Methode zu synthetisieren. Insbesondere gelang es hier erstmals, primäre Dihydroperoxide aus aliphatischen Aldehyden darzustellen. Desweiteren wurde erstmals eine größere Anzahl an enantiomerenreinen DHPs dargestellt. Weitere DHPs konnten durch Ozonolyse von olefinischen Terpenen mit etherischer Wasserstoffperoxidlösung dargestellt werden. Die enantiomerenreinen DHPs wurden verwendet, um enantioselektiv sowohl 2-substituierte Naphthochinone wie auch Allylalkohole, insbesondere tertiäre Allylalkohole, zu epoxidieren. Die Epoxide der letzteren sind nach der normalerweise verwendeten Methode nach Sharpless nicht zugänglich. Außerdem konnten durch Sulfidoxidation Sulfoxide enantiomerenangereichert dargestellt werden. Dies stellt die erste Nutzung von geminalen Dihydroperoxiden zur enantioselektiven Sauerstoffübertragung dar. Die primären aliphatischen gem-DHPs wurden desweiteren zur Darstellung bisher unbekannter 1,2,4,5-Tetroxane genutzt. Insbesondere wurde gefunden, daß durch Kondensation mit Orthoestern verläßlich alkoxysubstituierte Tetroxane erzeugt werden können. Diese wurden in der Literatur bisher nur an sehr wenigen Beispielen beschrieben. / In the course of this dissertation thesis the preparation and reactions of geminal dihydroperoxides were researched. The hereby synthesized dihydroperoxides were used as an oxygen transfer reagent, especially for enantioselective epoxidation, as well as a building block for the synthesis of 1,2,4,5-tetroxanes. A method for synthesis of gem-dihydroperoxides that was found in our workgroup was first optimized concerning reaction conditions, and later utilized to synthesize a large number of dihydroperoxides. It was notably possible to synthesize primary DHPs from aliphatic aldehydes for the first time. Also for the first time, a large number of enantiomerically pure gem-DHP was prepared by this method. Additional enantiomerically pure DHPs were made by ozonolysis of olefinic terpenes using ethereal hydrogen peroxide solution. The enenantiomerically pure DHPs were utilized to both epoxidize 2-substituted naphthoquinones as well as allylic alcohols, especially tertiary allylic alcohols. The latter kind does not react via the normally used Sharpless epoxidation. Additionally, enantioenriched sulfoxides could be prepared from sulfides. This is the first time that geminal dihydroperoxides were used for enantioselective oxygen transfer. Primary aliphatic DHPs were further utilized to prepare previously unknown 1,2,4,5-tetroxanes. Notably it was found that condensation with orthoesters reliably yielded alkoxy-substiuted tetroxanes. These were only described in a very few cases in literature before.
23

Avaliação dos efeitos anticancerígenos dos 1,2,3-triazóis derivados do núcleo 1,4-naftoquinona em linhagens leucêmicas humanas / Evaluation of anticancer effects of 1,2,3-triazoles derivates to the nucleus 1,4-naphthoquinone in human leukemic cell lines.

Coulidiati, Tangbadioa Herve 18 September 2014 (has links)
Made available in DSpace on 2015-05-14T13:00:01Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 12194499 bytes, checksum: cf6dad6e7629970dd8e06f4179a17141 (MD5) Previous issue date: 2014-09-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The triazole nucleus and its derivatives have attracted considerable attention in recent decades for their chemotherapeutic potentials. Specifically, the interest in molecules containing the 1,2,3-triazole as chemotherapeutic agents for various diseases has increased, because they are known to exhibit a wide range of biological activities, such as anti-proliferative and anti-neoplastic. The aim of this study was to evaluate the potencial anti-cancer effect of new triazole derivatives from 1,4-naphthoquinone, elucidating their cytotoxicity and cell death mechanisms involved. From five cancer cell lines tested, leukemic cells (HL-60 and K562) were the most sensitive, and between the eight triazole compounds tested (called C1 to C8), compounds C2 and C3 showed the best IC50 of 14 μM and 41 μM for HL-60 cells and 24 μM and 81 μM for K562 cells, respectively. However, these two compounds showed very little cytotoxic effect towards PBMC normal cells with IC50 superior to 80 μM. Investigating the type of cell death induced by compounds C2 and C3, it was showed that compounds induced apoptosis in HL-60 cells and cell cycle arrest in the S-phase, and necrosis in K562 ones. Cell cycle arrest in S phase was related to the expression of the p21 gene in K562. Results revealed a reduced expression of Bcl-2 protein and an increased expression of BAX protein in HL-60 cells. Moreover, it was found cytochrome c release, suggesting involvement of the intrinsic pathway in apoptosis induction in these cells. Activation of this pathway may be through inhibition of ERK phosphorylation. Our results also showed that pre-treatment of HL-60 cells with N-acetyl cysteine (1 mM) for 1 hour reduced the cytotoxic effect of compounds C2 and C3 for 30,83% and 26,47% respectively; indicating that the induction of apoptosis in HL-60 is mediated by increased production of intracellular ROS. Thus, it can be concluded that C2 and C3 compounds showed cytotoxic effects on HL-60 and K562 cells, so, can be considered as prototype anti-leukemic molecules. / O núcleo triazol e seus derivados têm atraído uma atenção considerável nessas últimas décadas devido ao seu potencial quimioterápico. Mais especificamente, tem se verificado o interesse em moléculas que contêm o grupo 1,2,3-triazol, isto porque esta classe de heterocíclicos é conhecida por exibir uma vasta gama de atividades biológicas, tais como, anti-proliferativo e anti-neoplásico. O objetivo desse trabalho foi o de avaliar o potencial anticancerígeno de novos triazóis derivados do 1,4-naftoquinona, elucidando as suas citotoxicidades e o mecanismo de morte envolvido. Os resultados obtidos revelaram que, das cinco linhagens cancerígenas testadas, as linhagens leucêmicas HL-60 e K562 foram as mais sensíveis, e dentre os oito compostos (denominados C1 a C8) testados, C2 e C3 foram os mais citotóxicos, apresentando CI50 de 14 μM e 41 μM, em HL-60 e de 24 μM e 81 μM em K562, respectivamente. Entretanto, os compostos foram menos citotóxicos nas células normais do sangue periférico humano com CI50 acima 80 μM. Investigando o tipo de morte induzido pelos compostos nas duas linhagens, foi demonstrado que os compostos C2 e C3 induziram apoptose em HL-60. Já nas células K562, este dois derivados provocaram a parada do ciclo celular na fase S e necrose. A parada do ciclo celular na fase S em K562 foi relacionada com a expressão do gene p21. Foi revelado a diminuição da expressão da proteína Bcl-2 e o aumento da expressão da proteína BAX nas células HL-60, e ainda verificou-se a liberação do citocromo c sugerindo a participação da via intrínseca na indução da apoptose em HL-60. A ativação dessa via pode ser via inibição da fosforilação da proteína ERK. Os resultados mostraram também que durante uma hora de pré-tratamento das células HL-60 com o N-acetil cisteina (1 mM), houve a redução da citotoxicidade dos compostos C2 e C3 de 30,83% e 26,47% respectivamente; indicando que a indução da apoptose em HL-60 é mediada pelo aumento da produção das espécies reativas de oxigênio intracelulares. Dessa forma, pode-se concluir que os compostos C2 e C3 apresentaram efeitos citotóxicos frente às linhagens HL-60 e K562, então, podem ser considerados como protótipo de moléculas anti-leucêmicas.

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