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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

Obten??o de rutina ricinoleato atrav?s da rea??o de esterifica??o com ?leo de mamona

Ribeiro, Fernanda Pinheiro de Carvalho 03 August 2016 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2017-07-12T22:04:17Z No. of bitstreams: 1 Tese vers?o final com ficha.pdf: 2919026 bytes, checksum: e0cf3c8db3a8cc81cb105cb2fbb154b3 (MD5) / Made available in DSpace on 2017-07-12T22:04:17Z (GMT). No. of bitstreams: 1 Tese vers?o final com ficha.pdf: 2919026 bytes, checksum: e0cf3c8db3a8cc81cb105cb2fbb154b3 (MD5) Previous issue date: 2016-08-03 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The flavonoid rutin (3-0-rutinos?deo-quercetin) stands out among the natural products as a promising alternative in the fight against degenerative diseases and related to aging. However, the low solubility and stability thereof in different media, especially lipophilic limited applications in pharmaceutical preparations. The biocatalytic transformation by enzymatic acylation has been suggested by several authors, with good reaction yields. In this sense, the objective of this study was to promote the enzymatic acylation of rutin, using castor oil as acylating agent and lipase as a catalyst, to characterize the formed product, estimate the efficiency of bioconversion, and to investigate in vitro the antioxidant activity and cytotoxic effect opposite the reaction product Vero cells. The catalytic transformation occurred at 50?C for 120 hours. The product was subjected to column chromatography, followed by filtration by Sephadex LH-20. The chemical structure of rutin-O-ricinoleate was determined by Nuclear Magnetic Resonance (NMR) 1H and 13C and by liquid chromatography / mass spectroscopy (HPLC/MS). In another experiment, it was observed the formation of the ester content by High Performance Liquid Chromatography coupled to a detector diode arrangements (HPLC-DAD) under conditions which allow assessing the reaction yield over 120 hours. The analytical method proposed has been validated considering the linearity parameters, accuracy, precision, limit of quantification and detection proved to be suitable for quantification of ricinoleato rutin. It was found by this method that the reaction product maintained the antioxidant capacity of rutin and there was no evidence of cytotoxicity. / O flavonoide rutina (quercetina-3-0-rutinos?deo) se destaca entre os produtos naturais como uma alternativa promissora no combate ?s doen?as degenerativas e relacionadas ao envelhecimento. No entanto, a baixa solubilidade e estabilidade da mesma em diferentes meios, especialmente lipof?licos, limitam as aplica??es em prepara??es farmac?uticas. A transforma??o biocatal?tica, atrav?s da acila??o enzim?tica, tem sido sugerida por diversos autores, com bons rendimentos reacionais. Neste sentido, o objetivo do presente trabalho foi promover a acila??o enzim?tica da rutina, utilizando ?leo de mamona como agente acilante e lipase como catalizador, caracterizar o produto formado, estimar o rendimento da bioconvers?o, al?m de investigar in vitro a atividade antioxidante e o efeito citot?xico do produto reacional frente ?s c?lulas Vero. A transforma??o catal?tica ocorreu em temperatura de 50?C, durante 120 horas. O produto foi submetido ? cromatografia em coluna, seguida de filtra??o por Sephadex LH-20. A estrutura qu?mica da rutina-O-ricinoleato, foi determinada por Resson?ncia Magn?tica Nuclear (RMN) 1H e de 13C e por cromatografia l?quida/espectroscopia de massas (CLAE/EM). Em outro experimento, foi verificado o teor de forma??o do ?ster por Cromatografia ? L?quidos de Alta Efici?ncia acoplado a um detector de arranjos Diodos (CLAE-DAD), em condi??es que permitiram avaliar o rendimento reacional ao longo de 120 horas. O m?todo anal?tico proposto foi validado considerando os par?metros de linearidade, exatid?o, precis?o, Limites de quantifica??o e de detec??o mostrando-se adequado para a quantifica??o da rutina ricinoleato. Verificou-se pelos m?todos avaliados, que o produto reacional manteve a capacidade antioxidante da rutina e que n?o houve evid?ncia de citotoxicidade.
2

S?ntese enzim?tica de biosurfactante e sua aplicabilidade na ind?stria do petr?leo / Enzymatic synthesis of the biosurfactant and application in the petroleum industry

Medeiros, Suzan Ialy Gomes de 02 March 2007 (has links)
Made available in DSpace on 2014-12-17T15:41:42Z (GMT). No. of bitstreams: 1 SusanIGM_Capa_ate_Cap2.pdf: 775391 bytes, checksum: bff1b25a943d2e8086f1be8fb59414cc (MD5) Previous issue date: 2007-03-02 / Enzymes have been widely used in biosynthesis/transformation of organic compounds in substitution the classic synthetic methods. This work is the first writing in literature of enzymatic synthesis for attainment the biossurfactants, the use glucose sucrose, ricinoleic acid e castor oil as substratum, and as biocatalyst, used immobilized lipase Thermomyces lanuginose, Rhizomucor miehei and the Candida antarctica lipase B; alkaline protease and neutral protease from Bacillus subtillis and yeast Saccharomyces cerevisiaeI. The analysis of HPLC (high performance liquid chromatography) showed that highest conversions were reached of used the alkaline protease from Bacillus subtillis. Laboratory tests, to evaluate the applicability, indicated that the produced biosurfactantes had good stability in presence of salts (NaCl) and temperature (55 e 25?C), they are effective in the reduction of the superficial tension and contac angle, but they have little foaming capacity, when compared with traditional detergents. These results suggest that the prepared surfactants have potential application as wetting agent and perforation fluid stabilizer / Enzimas t?m sido largamente utilizadas em ma??es de compostos org?nicos em substitui??o aos m?todos sint?ticos cl?ssicos. Esta disserta??o de mestrado ? o primeiro relato escrito em literatura de s?ntese enzim?tica para obten??o de biosurfactantes utilizando como substratos glicose, ?cido ricinol?ico e ?leo de mamona, e como biocatalizador, foram empregadas lipases imobilizadas (Thermomyces lanuginosa, Rhizomucor miehei e Candida antarctica B), proteases (Bacillus subtillis alcalina e Bacillus subtillis neutra) e levedura (Saccharomyces cerevisiae). A an?lise por CLAE (cromatografia l?quida de alta efici?ncia) mostrou que maiores convers?es foram alcan?adas pelo uso da Bacillus subtillis alcalina. Testes de laborat?rio, para avaliar sua aplicabilidade, indicaram que os biosurfactantes produzidos apresentam boa estabilidade em presen?a de NaCl e temperaturas de 55 e 25?C, s?o efetivos na redu??o da tens?o superficial e ?ngulo de contato, mas possuem pouca capacidade espumante, quando comparados aos detergentes tradicionais. Estes resultados sugerem que os surfactantes obtidos t?m potencial aplica??o como agente de molhabilidade e estabilizador de fluidos de perfura??o / 2020-01-01

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