• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 11
  • Tagged with
  • 11
  • 11
  • 6
  • 6
  • 6
  • 6
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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.
11

Validação de metodologias analíticas para quantificação de quercetina e canferol em extratos hidrolisados de folhas de rubus erythrocladus, rubus idaeus e morus nigra e screening antifúngico destes extratos

Tallini, Luciana Ruschel January 2014 (has links)
Neste trabalho utilizou-se a cromatografia líquida de alta eficiência (CLAE) e a eletroforese capilar (EC) como ferramentas analíticas para avaliação de flavonoides em extratos hidrolisados de folhas de Rubus e de Morus. Os extratos foram preparados por hidrólise ácida em ultrassom e analisados por CLAE-DAD e EC-DAD. Os métodos elaborados foram validados e aplicados. Quercetina e canferol foram identificados nestes extratos por CLAE-DAD, EC-DAD e CLUE-DAD/EM. Em Rubus erythrocladus quantificou-se 848,43 ± 66,68 μg.g-1 e 304,35 ± 17,29 μg.g-1 de quercetina e canferol, respectivamente, por CLAE-DAD e 836,37 ± 149,43 μg.g-1 de quercetina por EC-DAD. Em Rubus idaeus quantificou-se 698,32 ± 1,29 μg.g-1 e 184,20 ± 4,34 μg.g-1 de quercetina e canferol, respectivamente, por CLAE-DAD. Em Morus nigra quantificou-se 2323,90 ± 145,35 μg.g-1 e 1446,36 ± 59,00 μg.g-1, de quercetina e canferol, respectivamente, por CLAE-DAD e 2552,82 ± 275,30 μg.g-1 e 1188,67 ± 99,21 μg.g-1 de quercetina e canferol, respectivamente, por EC-DAD. Não foi observada diferença significativa entre a quantificação por CLAE-DAD e por EC-DAD, porém o método por CLAE-DAD se mostrou muito mais sensível do que o método por EC-DAD. Os mesmos compostos também foram identificados nestes extratos por CLUE-DAD/EM. Por esta ferramenta analítica se pode observar uma diferença entre o perfil químico das amostras de Rubus e de Morus. Quatro amostras comerciais de folhas de amora foram analisadas, observando grandes variações nas concentrações de quercetina e de canferol presentes nestes extratos. Além disso, através de um screening de atividade antifúngico verificou-se que os extratos não hidrolisados de Rubus erythrocladus e Rubus idaeus apresentaram ação contra três espécies de fungos filamentosos patógenos humanos: Thichophyton rubrum 51, Microsporum gypseum 01 e Microsporum canis 40. / In this work we used the high performance liquid chromatography (HPLC) and capillary electrophoresis (CE) as analytical tools to evaluate the hydrolyzed flavonoids in extracts of Rubus and Morus leaves. The extracts were prepared by acid hydrolysis in ultrasound and analyzed by HPLC- DAD and CE -DAD. The developed methods were validated and applied. Quercetin and kaempferol were identified in these extracts by HPLC-DAD, EC-DAD and UPLC-DAD/MS. In Rubus erythrocladus were quantified 848.43 ± 66.68 μg.g-1 and 304.35 ± 17.29 μg.g-1 of quercetin and kaempferol, respectively, by HPLC-DAD and 836.37 ± 149.43 μg.g-1 of quercetina by CE –DAD. In Rubus idaeus were quantified 698.32 ± 1.29 μg.g-1 and 184.20 ± 4.34 μg.g-1 of quercetin and kaempferol, respectively, by HPLC-DAD. In Morus nigra were quantified 2323.90 ± 145.35 μg.g-1 and 1446.36 ± 59.00 μg.g-1 of quercetin and kaempferol, respectively, by HPLC-DAD and 2552.82 ± 275.30 μg.g-1 and 1188.67 ± 99.21 μg.g-1 of quercetin and kaempferol, respectively, by CE -DAD. No significant difference in quantification by HPLC-DAD and CE-DAD was observed, but the HPLC-DAD method proved to be more sensitive than EC-DAD method. The same compounds were also identified in these extracts by UPLC-DAD/EM. Using this analytical tool, it was possible to observe a difference in the chemical profile of Rubus and Morus extracts. Commercial samples of blackberry leaves tea were analyzed by HPLC-DAD and it was observed big variation in the concentrations of quercetin and kaempferol in these extracts. Moreover, through a screening antifungal activity, it was found that no hydrolyzed extracts of Rubus idaeus and Rubus erythrocladus showed action against three species of filamentous fungal human pathogens: Thichophyton rubrum 51, Microsporum gypseum 01 and Microsporum canis 40.

Page generated in 0.0309 seconds