No description available.

The preparation of 3B-(2-mercaptoethylamino)-cholestane was set as the goal of this thesis project.

A convenient, economical, large scale synthesis of N-acetyldehydro-alanine (a-acetamidoacrylic acid) and its methyl ester was developed via a sequence of N-chlorination-dehydrochlorination. The method was extended to the synthesis of the corresponding N-benzoyl, N-phenylacetyl and N-benzyloxycarbonyl derivatives. The conversion of a-methoxy-N-acetyl alanine derivatives to the corresponding a-mercapto alanine derivatives, using zinc chloride and an appropriate mercaptan, was investigated. Methyl a-methoxy-N-acetyl-D, L-alaninate was successfully converted to the a-acetylthio derivative, in 24% yield; however, a 90% yield could be obtained by treatment of the dehydroalanine derivative with hydrogen chloride gas in neat thiolacetic acid. A facile conversion of the a-acetylthio derivative to the a-methoxy derivative, using sodium methoxide in methanol, was observed to occur. The normally facile conversion of an acetylthio group to a mercapto group, using sodium borohydride, gave mixtures of the a-mercapto derivative and alanine derivative. The reactions at the a position of a-hetero-N-acetyl-D,L-alanines and a,B-disubstituted N-acetyl-D,L-alanine derivatives seemed consistent with the formation of an acylimine intermediate under basic conditions and a carbonium ion intermediate under acidic conditions. From these studies, a facile, clean synthesis of a-halo-a-mercapto-and a-alkoxy-N-acetyl-D,L-alanine derivatives was accomplished. All attempts to synthesize a,B-dimercapto derivatives failed because the B-halogen could not be replaced with a mercapto group when the a position was a mercapto or methoxy derivative. Attempts to generate a B-mercapto-a-halo derivative also failed. A facile synthesis of the E and Z isomers of methyl B-chloro-N-acetyldehydroalaninate was developed. The ratio of Z to E isomers was found to vary with the base used for the elimination. The E and Z isomers of methyl B-chloro-N-acetyldehydroalaninate were converted to the B-mercapto derivatives by reaction with mercaptan. The reaction proceeded with retention of stereochemistry. The formation of B-substituted N-acetyldehydroalanine derivatives seemed consistent with an acylimine intermediate followed by a sequence of Michael-type addition and dehydrochlorination. A study of the conversion of the B-mercapto-N-acetyldehydroalanine derivatives to mixed dithioacetals, which would be useful in the synthesis of natural antibiotics, was undertaken. This approach to the synthesis of mixed dithioacetals was unsuccessful because an exchange of mercapto groups was observed, the addition of a second, different mercaptan failed or the yield was too low to be synthetically useful. A synthesis of B,B-dimercapto-N-aeetyldehydroalanine (mixed, unsaturated dithioacetals) derivatives was accomplished. However, because of low yields, a reduction to B,B- dimercapto-N- acetyl-D,L-alanine derivatives (mixed dithloacetals) was not investigated.

The reaction of 5-bromo-5-ethylbarbituric acid with mercaptan and pyridine in cold ether solution was studied and was found to be satisfactory for the preparation of the compounds reported in this work.

Since no mention has been found in the literature of any 5-substituted mercapto-5-alkyl derivatives of barbituric acid, it was thought to be of interest to prepare a series of compounds containing sulfur attached directly to the barbituric acid nucleus. 5-substituted mercapto-5-isoamylbarbituric acids were chosen as representative of barbituric acids in which the alkyl group has a fairly high molecular weight.

Nesta dissertação estão descritos os resultados obtidos sobre a preparação de nanocascas funcionalizadas (nanopartículas ocas) de ouro/prata de diâmetro de 50 nm e imobilização de diferentes lipases (Burkholderia cepacia (BCL) e pâncreas de porco (PPL)). [Obs.: A imagem do esquema pode ser visto no arquivo PDF] Inicialmente as nanocascas de ouro/prata (NSs AgAu) foram sintetizadas e caracterizadas, através de imagens de MEV e MET. Através destas imagens algumas características das NSs AgAu foram elucidadas, como seu tamanho e sua característica oca. Em seguida, a funcionalização das NSs AgAu com diferentes moléculas mercapto-alcanóicas e uma molécula mercapto-amina foi realizada. Depois de funcionalizadas as NSs-funcionalizadas foram ativadas, com glutaraldeído ou EDC, para que assim elas ficassem aptas à imobilização das lipases, via ligação covalente. Para a BCL foi possível imobilizar 0,155-0,282 mg de proteína/3 mg do suporte. No caso da PPL uma menor quantidade de enzima foi imobilizada (0,035-0,048 mg/3 mg do suporte). A atividade da enzima imobilizada foi testada frente à reação de acetilação enantiosseletiva do (R,S)-1-feniletanol com acetato de vinila (RCE, resolução cinética enzimática). Excelentes resultados de conversão (50%) e seletividade (E > 200) foram conseguidos com a BCL imobilizada em todos os suportes. A PPL livre não catalisava a acetilação deste substrato e quando esta enzima foi imobilizada nas diferentes NSs-funcionalizadas, os resultados apresentados para acetilação enantiosseletiva do (R,S)-1-feniletanol com acetato de vinila foram interessantes. Nesse caso conseguimos alcançar conversões de até 4% do substrato R à sua forma acetilada com excelente enantiosseletividade ( > 99% e.e. do produto). Como uma alternativa de demonstrar a atividade enzimática da BCL imobilizada em reação tradicional de hidrólise, o teste da hidrólise do palmitato de p-Nitrofenila pela BCL livre e imobilizada foi realizado. Este teste revelou que a BCL imobilizada nas NSs-funcionalizadas catalisavam a hidrólise do palmitato de p-Nitrofenila mais rápido que a enzima livre, comprovando os bons resultados obtidos na RCE, mostrando que os sistemas onde tínhamos a BCL imobilizada foram mais eficientes que a enzima livre. As NSs AgAu, NSs-funcionalizadas e até as nanocascas contendo as lipases imobilizadas foram caracterizadas por de imagens de MEV e MET, análises de FT-IR e método de Bradford. Outros estudos com os sistemas contendo a BCL imobilizada foram elucidados. Diferentes funcionalizadores de diferentes tamanhos foram utilizados e a influência de cada um deles sobre a atividade enzimática foi estudado. Por exemplo, quando as NSs AuAg foram funcionalizadas com moléculas mercapto-alcanóicas menores, como por exemplo, o ácido mercapto acético, melhores resultados para a RC do (R,S)-1-feniletanol foram conseguidos. As diferentes formas de ativação da NSs-funcionalizadas utilizando glutaraldeído ou EDC, para consequente imobilização da BCL não resultaram em alterações da atividade enzimática na RC, apresentando valores idênticos para RCE. Experimentos para testar a estabilidade dos sistemas contendo a BCL imobilizada também foram feitos. Descobrimos que é possível armazenar a BCL imobilizada nos diferentes sistemas à - 4 °C por até 28 dias. O estudo da reciclagem destes sistemas revelou que por até 3 ciclos os sistemas conseguiram manter 90% da atividade enzimática. / This dissertation presents the results achieved on the preparation of functionalized gold/silver nanoshells (hollow nanoparticles, 50 nm) and immobilization of different lipases (Burkholderia cepacia (BCL) and porcine pancreatic (PPL)). Initially Gold/Silver nanoshells (NSs Ag Au) were synthesized and characterized through SEM and TEM pictures. By these images some characteristics of NSs AgAu were elucidated, as its size and hollow feature. The functionalization NSs AgAu with different mercapto-alkanoic molecules and mercapto-amine molecule was next step performed. After the functionalized NSs-functionalized were activated with glutaraldehyde or EDC, after that they remained suitable for the immobilization of lipases via covalent bond. BCL was possible immobilized 0.155-0.282 mg protein/3 mg of support. And the PPL a smaller amount of enzyme was immobilized (from 0.035-0.048 mg / 3 mg of support). The activity of the immobilized enzyme was assayed by the reaction enantioselective acetylation of (R,S)-1-phenylethanol with vinyl acetate (KR, kinetic resolution). Excellent conversion results (50%) and selectivity (E > 200) were achieved with the immobilized BCL. The free PLP did not catalyzed acetylation of the substrate and when this enzyme was immobilized on NSs-functionalized the results for enantioselective acetylation of (R,S)-1-phenylethanol with vinyl acetate were interesting. In this case we achieve conversions of 4% of the substrate (R) to acetylated form with excellent enantioselectivity (> 99% e.e. of the product). As alternative to demonstrate the enzymatic activity of BCL immobilized on traditional hydrolysis reaction, the hydrolysis of p-nitrophenyl palmitate by free and immobilized BCL was performed. This test revealed BCL immobilized on NSs-functionalized catalyzed hydrolysis of p-nitrophenyl palmitate faster than free enzyme, confirming the good results obtained in KR, showing that systems which had immobilized BCL were more efficient than the enzyme free. The NSs AgAu, NSs-functionalized and Nanoshells containing the immobilized lipases were characterized by SEM and TEM images , FT-IR analysis , the Bradford method. Other studies with systems containing immobilized BCL were elucidated. Different spacers with different sizes were used for functionalized the nanoshells, and the influence of each of the enzymatic activity was studied. For example, when the NSs were functionalized with smaller molecules mercapto-alkanoic and cysteamine best results for the KR (R,S)-1-(phenyl)ethanol were obtained. The different forms of activation of NSs-functionalized using glutaraldehyde or EDC, for subsequent immobilization of BCL did not result in changes in enzyme activity in the KR . Experiments to test the stability of systems containing immobilized BCL were also made . We found it possible to store the BCL immobilized on different systems at - 4 ° C for 30 days. The study of the recycling of these systems was made and by 3 cycles systems maintain 90% of the enzyme activity.

L'urée, apportée dans les engrais, fournit aux plantes l'azote nécessaire à leur croissance. Dans le sol, elle est convertie en ammoniac par les uréases, puis, via le procédé de nitrification, est oxydée en nitrites, puis en nitrates, éléments essentiels pour la nutrition des plantes. Mais, cet apport artificiel conduit à de nombreux déséquilibres écologiques dus à d'importants rejets d'azote au niveau atmosphérique et aquatique. C'est pourquoi les inhibiteurs d'uréases et de la nitrification, qui régulent la présence des différentes formes de l'azote dans le sol, sont d'un intérêt majeur en agriculture. Dans le cadre du projet AZOSTIMER, nous avons voulu améliorer l'efficacité du MBT, inhibiteur de la nitrification, et du NBPT, inhibiteur d'uréases. Nous avons tout d'abord souhaité améliorer l'hydrosolubilité, et ainsi la biodisponibilité du MBT et d'un homologue, le MBI, par mise à profit du concept de prodrogue. Ces molécules ont été conjuguées à des sucres par synthèse glycosidique et une famille d'inhibiteurs glycosylés a été préparée. Par la suite, les propriétés physico-chimiques (solubilité, stabilité), biologiques (écotoxicité, activité) et le comportement dans les sols (dégradabilité, mobilité) ont été évalués. Dans un second temps, nous avons voulu prolonger l'activité du NBPT dans les sols acides en limitant sa dégradation, soit par encapsulation dans une formulation, soit par modulations chimiques. De nombreuses formulations du NBPT ont été développées puis évaluées (stabilité en milieu acide, activité dans les sols). Des phosphoramides ont été synthétisés et évalués afin de mettre en évidence des relations structure-stabilité chimique et structure-activité.

Nesta dissertação estão descritos os resultados obtidos sobre a preparação de nanocascas funcionalizadas (nanopartículas ocas) de ouro/prata de diâmetro de 50 nm e imobilização de diferentes lipases (Burkholderia cepacia (BCL) e pâncreas de porco (PPL)). [Obs.: A imagem do esquema pode ser visto no arquivo PDF] Inicialmente as nanocascas de ouro/prata (NSs AgAu) foram sintetizadas e caracterizadas, através de imagens de MEV e MET. Através destas imagens algumas características das NSs AgAu foram elucidadas, como seu tamanho e sua característica oca. Em seguida, a funcionalização das NSs AgAu com diferentes moléculas mercapto-alcanóicas e uma molécula mercapto-amina foi realizada. Depois de funcionalizadas as NSs-funcionalizadas foram ativadas, com glutaraldeído ou EDC, para que assim elas ficassem aptas à imobilização das lipases, via ligação covalente. Para a BCL foi possível imobilizar 0,155-0,282 mg de proteína/3 mg do suporte. No caso da PPL uma menor quantidade de enzima foi imobilizada (0,035-0,048 mg/3 mg do suporte). A atividade da enzima imobilizada foi testada frente à reação de acetilação enantiosseletiva do (R,S)-1-feniletanol com acetato de vinila (RCE, resolução cinética enzimática). Excelentes resultados de conversão (50%) e seletividade (E > 200) foram conseguidos com a BCL imobilizada em todos os suportes. A PPL livre não catalisava a acetilação deste substrato e quando esta enzima foi imobilizada nas diferentes NSs-funcionalizadas, os resultados apresentados para acetilação enantiosseletiva do (R,S)-1-feniletanol com acetato de vinila foram interessantes. Nesse caso conseguimos alcançar conversões de até 4% do substrato R à sua forma acetilada com excelente enantiosseletividade ( > 99% e.e. do produto). Como uma alternativa de demonstrar a atividade enzimática da BCL imobilizada em reação tradicional de hidrólise, o teste da hidrólise do palmitato de p-Nitrofenila pela BCL livre e imobilizada foi realizado. Este teste revelou que a BCL imobilizada nas NSs-funcionalizadas catalisavam a hidrólise do palmitato de p-Nitrofenila mais rápido que a enzima livre, comprovando os bons resultados obtidos na RCE, mostrando que os sistemas onde tínhamos a BCL imobilizada foram mais eficientes que a enzima livre. As NSs AgAu, NSs-funcionalizadas e até as nanocascas contendo as lipases imobilizadas foram caracterizadas por de imagens de MEV e MET, análises de FT-IR e método de Bradford. Outros estudos com os sistemas contendo a BCL imobilizada foram elucidados. Diferentes funcionalizadores de diferentes tamanhos foram utilizados e a influência de cada um deles sobre a atividade enzimática foi estudado. Por exemplo, quando as NSs AuAg foram funcionalizadas com moléculas mercapto-alcanóicas menores, como por exemplo, o ácido mercapto acético, melhores resultados para a RC do (R,S)-1-feniletanol foram conseguidos. As diferentes formas de ativação da NSs-funcionalizadas utilizando glutaraldeído ou EDC, para consequente imobilização da BCL não resultaram em alterações da atividade enzimática na RC, apresentando valores idênticos para RCE. Experimentos para testar a estabilidade dos sistemas contendo a BCL imobilizada também foram feitos. Descobrimos que é possível armazenar a BCL imobilizada nos diferentes sistemas à - 4 °C por até 28 dias. O estudo da reciclagem destes sistemas revelou que por até 3 ciclos os sistemas conseguiram manter 90% da atividade enzimática. / This dissertation presents the results achieved on the preparation of functionalized gold/silver nanoshells (hollow nanoparticles, 50 nm) and immobilization of different lipases (Burkholderia cepacia (BCL) and porcine pancreatic (PPL)). Initially Gold/Silver nanoshells (NSs Ag Au) were synthesized and characterized through SEM and TEM pictures. By these images some characteristics of NSs AgAu were elucidated, as its size and hollow feature. The functionalization NSs AgAu with different mercapto-alkanoic molecules and mercapto-amine molecule was next step performed. After the functionalized NSs-functionalized were activated with glutaraldehyde or EDC, after that they remained suitable for the immobilization of lipases via covalent bond. BCL was possible immobilized 0.155-0.282 mg protein/3 mg of support. And the PPL a smaller amount of enzyme was immobilized (from 0.035-0.048 mg / 3 mg of support). The activity of the immobilized enzyme was assayed by the reaction enantioselective acetylation of (R,S)-1-phenylethanol with vinyl acetate (KR, kinetic resolution). Excellent conversion results (50%) and selectivity (E > 200) were achieved with the immobilized BCL. The free PLP did not catalyzed acetylation of the substrate and when this enzyme was immobilized on NSs-functionalized the results for enantioselective acetylation of (R,S)-1-phenylethanol with vinyl acetate were interesting. In this case we achieve conversions of 4% of the substrate (R) to acetylated form with excellent enantioselectivity (> 99% e.e. of the product). As alternative to demonstrate the enzymatic activity of BCL immobilized on traditional hydrolysis reaction, the hydrolysis of p-nitrophenyl palmitate by free and immobilized BCL was performed. This test revealed BCL immobilized on NSs-functionalized catalyzed hydrolysis of p-nitrophenyl palmitate faster than free enzyme, confirming the good results obtained in KR, showing that systems which had immobilized BCL were more efficient than the enzyme free. The NSs AgAu, NSs-functionalized and Nanoshells containing the immobilized lipases were characterized by SEM and TEM images , FT-IR analysis , the Bradford method. Other studies with systems containing immobilized BCL were elucidated. Different spacers with different sizes were used for functionalized the nanoshells, and the influence of each of the enzymatic activity was studied. For example, when the NSs were functionalized with smaller molecules mercapto-alkanoic and cysteamine best results for the KR (R,S)-1-(phenyl)ethanol were obtained. The different forms of activation of NSs-functionalized using glutaraldehyde or EDC, for subsequent immobilization of BCL did not result in changes in enzyme activity in the KR . Experiments to test the stability of systems containing immobilized BCL were also made . We found it possible to store the BCL immobilized on different systems at - 4 ° C for 30 days. The study of the recycling of these systems was made and by 3 cycles systems maintain 90% of the enzyme activity.

Submitted by JANAINE DO ROCIO IVASSECHEN null (janaine_jri@yahoo.com.br) on 2016-02-23T23:37:58Z No. of bitstreams: 1 dissertação Janaíne.pdf: 2608394 bytes, checksum: 89d6d43b306c92a291cb379448dd11de (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-02-24T14:58:59Z (GMT) No. of bitstreams: 1 ivassechen_jr_me_araiq.pdf: 2608394 bytes, checksum: 89d6d43b306c92a291cb379448dd11de (MD5) / Made available in DSpace on 2016-02-24T14:58:59Z (GMT). No. of bitstreams: 1 ivassechen_jr_me_araiq.pdf: 2608394 bytes, checksum: 89d6d43b306c92a291cb379448dd11de (MD5) 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.

Orientador: Pablo A. Fiorito / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-graduação em Ciência e Tecnologia/Química.