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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

Atividade antimicrobiana e antioxidante de Licania rigida e Turnera ulmifolia

Morais, Leandro Vin?cius Fernandes de 30 March 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-16T21:49:55Z No. of bitstreams: 1 LeandroViniciusFernandesDeMorais_DISSERT.pdf: 1776137 bytes, checksum: 5be63e56c13449063a3882ed83b373a2 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-19T23:34:37Z (GMT) No. of bitstreams: 1 LeandroViniciusFernandesDeMorais_DISSERT.pdf: 1776137 bytes, checksum: 5be63e56c13449063a3882ed83b373a2 (MD5) / Made available in DSpace on 2016-08-19T23:34:37Z (GMT). No. of bitstreams: 1 LeandroViniciusFernandesDeMorais_DISSERT.pdf: 1776137 bytes, checksum: 5be63e56c13449063a3882ed83b373a2 (MD5) Previous issue date: 2015-03-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Licania rigida Benth e a Turnera ulmifolia Linn. var. elegans s?o esp?cies de plantas regionais do semi?rido empregadas no tratamento de diversas doen?as. Objetivos: O intuito desse trabalho foi caracterizar quimicamente os extratos e fra??es e investigar o potencial antimicrobiano e antioxidante. Metodologia: Para a an?lise qu?mica foram realizadas a quantifica??o total de compostos fen?licos por espectrofotometria e a caracteriza??o cromatogr?fica dos extratos e fra??es. A avalia??o da atividade antioxidante foi realizada pela determina??o da capacidade de sequestro do radical DPPH?. A atividade antimicrobiana foi avaliada pelos ensaios de difus?o em ?gar, microdilui??o em caldo e cin?tica de morte. Resultados: Os extratos e fra??es de L. rigida e T. ulmifolia apresentaram elevado conte?do fen?lico, com a presen?a de flavonoides, dos quais foram determinados como marcadores qu?micos. Observou-se que os extratos de ambas as esp?cies agiram como agentes sequestradores no ensaio da atividade antioxidante in vitro. O extrato da L. rigida foi a ?nica ativa contra cepas de S. aureus, S. aureus meticilina resistente, S. epidermidis, e as leveduras, Candida albicans, Candida dubliniensis, Candida tropicalis, Candida parapsilosis, Candida rugosa, Candida krusei eTrichosporon asahii. Conclus?o: Com base nesses resultados ? poss?vel afirmar que atividade antioxidante e antimicrobiana possivelmente ? atribu?da a presen?a de polifen?licos e flavonoides evidenciados nos extratos e fra??es. / Introduction: Licania rigida Benth and Turnera ulmifolia Linn. var. elegans are species of semi-arid regional plants used in the treatment of various diseases. Objectives: The purpose of this study was chemically characterize the extracts and fractions and investigate the antimicrobial and antioxidant potential. Methods: For chemical analysis, were performed spectrophotometric quantification of the total phenolic and characterization of the extracts by chromatographic analysis. Evaluation of antioxidant activity was done by determining the radical scavenging capacity DPPH ?. Antimicrobial activity was evaluated by agar diffusion, broth microdilutionand time-kill assays. Results: The extracts and fractions L. rigid and T. ulmifolia showed a high phenolic content, the presence of flavonoids, which were determined as chemical markers. It was observed that the extracts of both species performed as sequestering agents in the trial of antioxidant activity in vitro. The L. rigida extract was the only active front strains of S. aureus 33591 (methicillin-resistant), S. aureus 29213, S. epidermidis 12228, and also against the yeast, Candida albicans, Candida dubliniensis, Candida tropicalis, Candida parapsilosis, Candida rugosa, Candida krusei eTrichosporon asahii. Conclusions: Based on these results it is possibly affirm the antioxidant and antimicrobial activity of L. rigida and attributed the presence of polyphenolic flavonoid like responsible.
2

Avalia??o funcional e estrutural de um novo pept?deo antimicrobiano do escorpi?o Tityus stigmurus

Melo, Edinara Targino de 31 March 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-02T23:14:28Z No. of bitstreams: 1 EdinaraTarginoDeMelo_DISSERT.pdf: 2062041 bytes, checksum: b2de2a9d0f47d751e6c33c3d69b984a7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-04T23:26:34Z (GMT) No. of bitstreams: 1 EdinaraTarginoDeMelo_DISSERT.pdf: 2062041 bytes, checksum: b2de2a9d0f47d751e6c33c3d69b984a7 (MD5) / Made available in DSpace on 2016-03-04T23:26:34Z (GMT). No. of bitstreams: 1 EdinaraTarginoDeMelo_DISSERT.pdf: 2062041 bytes, checksum: b2de2a9d0f47d751e6c33c3d69b984a7 (MD5) Previous issue date: 2014-03-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / No Brasil, ? grande a incid?ncia de animais pe?onhentos, dentre os quais se destacam os escorpi?es por sua import?ncia m?dica, sendo sua pe?onha fonte de diversas subst?ncias qu?micas com atividades biol?gicas e farmacol?gicas ainda n?o compreendidas, incluindo diversos pept?deos bioativos. Pept?deos antimicrobianos (PAMs) s?o componentes do sistema imune de procariotos e eucariotos utilizados como primeira linha de defesa contra micro-organismos. No presente trabalho, foi caracterizado o primeiro PAM do escorpi?o Tityus stigmurus, nomeado Stigmurina, previamente identificado por meio do transcriptoma da gl?ndula de veneno desta esp?cie. As caracter?sticas da Stigmurina foram investigadas por modelagem computacional e constru??o de dendrograma. Al?m disso, as caracter?sticas estruturais da Stigmurina foram investigadas por dicro?smo circular em ?gua, em 2, 2, 2- trifluoethanol (TFE) e em dodecil sulfato de s?dio (SDS) e os modelos refinados por simula??es de din?mica molecular. Testes in vitro foram empregados para investigar a atividade antibacteriana, antif?ngica, hemol?tica e citot?xica do veneno bruto e da Stigmurina. Os resultados mostraram que a sequ?ncia selecionada codifica uma prote?na madura com 17 res?duos de amino?cidos e o dendrograma revela um caso de converg?ncia evolutiva. Os espectros de dicro?smo demonstraram flexibilidade conformacional, predominando estrutura estendida e ??folha, al?m de not?vel capacidade de renatura??o. A pe?onha bruta n?o apresentou atividade relevante nos testes antimicrobianos para as concentra??es testadas. No entanto, a Stigmurina mostrou um amplo espectro de atividade antibacteriana, com concentra??es inibit?rias m?nimas (CIMs) entre 31,25?g/mL a 250 ?g/mL para diferentes micro-organismos, enquanto que os resultados para a avalia??o da atividade hemol?tica nestas concentra??es foram baixas. Nos estudos de citotoxicidade, a pe?onha bruta foi incapaz de reduzir a viabilidade celular em c?lulas VERO E6, por?m sua toxicidade em c?lulas SiHa foi significativamente superior, correspondendo a uma IC50 de 3,6 ?g/mL. J? nos testes com a Stigmurina, as concentra??es capazes de reduzir a viabilidade celular das c?lulas VERO E6 e SiHa em 50% foram de 275,67 ?g/mL e 212,54 ?g/mL, respectivamente.Os resultados sugerem que a Stigmurina poder ser considerada como um potencial medicamento anti-infeccioso. / In Brazil, there is a high incidence of venomous animals. Among them, scorpions are highlighted by their medical importance, and for being their venom a source of several molecules with biological and pharmacological activity not yet fully understood, including several bioactive peptides. Antimicrobial peptides (AMPs) are components of the immune system in prokaryotes and eukaryotes, used in the first line of defense against microorganisms. In the present study, we characterized the first PAM previously identified through transcriptome of the venom gland of the scorpion Tityus stigmurus, named Stigmurin. The characteristics of Stigmurin were investigated by computational modeling and construction of dendrogram. In vitro tests investigated the antibacterial, antifungal, haemolytic and cytotoxic effects of crude venom and Stigmurin. In addition, the structural characteristics of Stigmurin were investigated by circular dochroism in water, 2, 2 , 2- trifluoethanol (TFE) and sodium dodecyl sulfate (SDS) and the models were refined by molecular dynamics simulations. The results showed that the selected sequence encodes a mature protein of 17 amino acid residues and the dendrogram reveals a case of convergent evolution. The crude venom showed no antimicrobial activity, however, Stigmurin exhibited a broad spectrum of antibacterial activity, with minimal inhibitory concentrations (MIC) ranging from 31.25 and 250 ?g/mL for different strains, while the hemolytic activity at these concentrations was low. In cytotoxicity studies, the crude venom was unable to reduce cell viability in VERO E6 cells; in contrast, its activity in SiHa cells was significantly higher, corresponding to IC50 of 3.6 ?g/mL. For Stigmurin the concentration sable to decrease cell viability of Vero E6 and SiHa cells in 50% were 275.67 ?g/mL and 212.54 ?g/mL, respectively. The dichroism spectra revealed the conformational flexibility, with predominating extended and ??sheet structures, as well as a remark able renaturation ability. The results suggest that Stigmurin could be considered as a potential antiinfective drug

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