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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

Estudo quÃmico de Cestrum laevigatum Schlecht (Solanaceae) / Chemical study of Cestrum laevigatum Schlecht (Solanaceae)

Roberta Ãrika de Souza Silva 27 February 2009 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O presente trabalho relata o estudo quÃmico do caule de Cestrum laevigatum Schlecht (Solanaceae), coletado no municÃpio de Pacoti-CE. A partir da investigaÃÃo do extrato etanÃlico utilizando tÃcnicas clÃssicas de cromatografia de adsorÃÃo (gel de sÃlica e sÃlica flash) e exclusÃo (Sephadex LH-20) foi possÃvel o isolamento de esterÃides e um triterpeno. Os esterÃides de esqueleto espirostano foram caracterizados como uma mistura de sapogeninas 25(S)-5-espirostano-2,3-diol e 25(R)-5-espirostano-2,3-diol (gitogenina) (CL-1), a mistura de epÃmeros (25R)-5-espirostano-2,3-diol-3-O--D-galactopiranosÃdeo e (25S)-5-espirostano-2,3-diol-3-O--D-galactopiranosÃdeo (CL-2), e a mistura epimÃrica da saponina de carÃter inÃdito na literatura (25R,S)-5-espirostan-2,3-diol-3-O--D-galactopiranosil(1→4)- -D-galactopiranosil(1→4)--D-glicopiranosil (CL-3). AlÃm destes compostos, foram isolados ainda a mistura dos esterÃides -sitosterol e estigmasterol (CL-5) e seus derivados glicosilados (CL-6), alÃm do triterpeno pentacÃclico de esqueleto do tipo lupano β-lup-20(29)-en-3-ol (lupeol) (CL-4). A caracterizaÃÃo estrutural dos compostos isolados foi possÃvel atravÃs do uso de tÃcnicas espectroscÃpicas, principalmente RMN, incluindo seqÃÃncias de pulso uni e bidimensionais, e comparaÃÃo com dados relatados na literatura. Das saponinas investigadas quanto ao potencial antimicrobiano, apenas CL-3 mostrou-se ativa contra Bacillos subtilis, Pseudomonas aeruginosa e Enterobacter aerogenes. A atividade leishmanicida foi realizada com CL-1, CL-2 e CL-3, porÃm, apenas CL-3 mostrou-se ativa contra Leishmania amazonensis. Em relaÃÃo à atividade antifÃngica, CL-1 mostrou-se ativa apenas contra Microsporum canis. CL-2 apresentou excelentes resultados contra Candida albicans, Trichophyton rubrum e Trichophyton mentagrophytes, e uma atividade relativamente boa contra Microsporum canis. Jà CL-3 aparece revelou uma excelente atividade antifÃngica contra todas as cepas testadas. Os resultados promissores obtidos atà o momento a partir do extrato etanÃlico do caule de C. laevigatum confirmam o grande potencial quÃmico/farmacolÃgico das espÃcies deste gÃnero, e justificam a importÃncia do trabalho realizado / This work reports the chemical study of the stem of Cestrum laevigatum Schlecht (Solanaceae), collected at the Pacoti-CE. The investigation of the ethanol extract using conventional techniques of adsorption chromatography (silica gel and silica flash) and exclusion (Sephadex LH-20) was possible the isolation of steroids and triterpene. The spirostan steroids have been characterized as the mixture at the sapogenins 25(S)-5-espirostan-2,3-diol and 25(R)-5-espirostan-2,3-diol (gitogenin) (CL-1), a mixture of epimers (25R)-5-espirostan-2,3-diol-3-O--Dgalactopyranoside and (25S)-5-espirostan-2,3-diol-3-O--D-galactoyiranoside (CL-2), and the mixture of new epimer (25R,S)-5-espirostan-2,3-diol-3-O--Dgalactopyranosil(1→4)--D-galactopyranosil(1→4)--D-glicopyranosil (CL-3). Besides these compounds, were also isolated the mixture of steroids β-sitosterol and stigmasterol (CL-5) and its glycosides (CL-6), and the pentacyclic triterpene β-lup-20(29)-en-3-ol (lupeol) (CL-4). The structural characterization of the isolated compounds was possible through the use of spectroscopic techniques, mainly NMR, including sequences of uni and bidimensional pulse, and comparison with literature data. CL-3 was shown to be active against Bacille subtilis, Pseudomonas aeruginosa and Enterobacter aerogenes. The leishmanicide activity was performed with CL-1, CL-2 and CL-3, however, only CL-3 was shown to be active against Leishmania amazonensis. For the antifungical activity, CL-1 was shown to be active only against Microsporum canis. CL-2 showed excellent results against Candida albicans, Trichophyton rubrum and Trichophyton mentagrophytes, and a relatively good activity against Microsporum canis. CL-3 appears with excellent activity antifungical against all strains tested. The promising results obtained so far from the ethanol extract of the stem of C. laevigatum confirm the great potential chemical / pharmacological species of this genus, and justify the importance of work

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