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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 fitoquÃmico e avaliaÃÃo do potencial de inibiÃÃo da enzima acetilcolisnesterase de Simarouba versicolor (SIMAROUBACEAE) / Phytochemical study and evaluate the potential inhibition of the enzyme acetilcolisnesterase Simarouba versicolor (SIMAROUBACEAE)

Josà Ivan Ximenes de Carvalho 04 November 2008 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O presente trabalho descreve o estudo quÃmico e farmacolÃgico da casca do caule da espÃcie Simarouba versicolor, pertencente à famÃlia Simaroubaceae. A espÃcie ocorre preferencialmente em Ãreas abertas de solos bem drenados, como cerrados e caatinga. Conhecida popularmente como âpau paraÃbaâ, âmata-cachorroâ ou âsimaruba do Brasilâ, a casca do seu caule possui propriedades inseticida e antihelmÃntica. Com o objetivo de estabelecer uma possÃvel relaÃÃo extrato atividade de inibiÃÃo da enzima acetilcolinesterase (AChE). Foi realizada uma triagem dos extratos das partes (folhas, talos, Galhos, Casca do caule e Cerne) da espÃcie Simarouba versicolor, atravÃs do ensaio de Ellman. O extrato etanÃlico da casca do caule apresentou elevada inibiÃÃo da AChE, desse extrato, as fraÃÃes clorofÃrmica e acetato de etila foram identificadas como sendo responsÃveis pela inibiÃÃo da enzima. A prospecÃÃo quÃmica da fraÃÃo clorofÃrmica resultou no isolamento de trÃs compostos, uma mistura de esterÃides β- sitosterol e estigmasterol, um quassinÃide, a 11-acetilamarolida e o alcalÃide 4,5- dimetÃxicantin-6-ona. Na fraÃÃo acetato de etila foi isolado o 3-β-O-β-D-glicopiranosil sistosterol. A determinaÃÃo estrutural desses compostos foi realizada atravÃs de anÃlise espectroscÃpica pelos mÃtodos de IV, EM, RMN1H e 13C-BB utilizando tÃcnicas uni e bidimensionais e por comparaÃÃo com dados descritos na literatura. Na anÃlise qualitativa de inibiÃÃo AChE os extratos e os constituintes isolados 11-acetilamarolida e 4,5-dimetÃxicantin-6-ona apresentaram bons resultados. Os extratos tambÃm apresentaram atividade citotÃxica em trÃs linhagens tumorais testados. / The present paper describes the chemical and pharmacological study of the stem bark of the species Simarouba versicolor, which belongs to the family Simaroubaceae. The species are found, mainly in open areas of well drained soils such as cerrado and caatinga. Known popularly as âpau Paraibaâ, âmata-cachorroâ or âBrazilian simarubaâ, the bark of its trunk has insecticidal and antihelminthic properties. It aims to establish a possible extract inhibition of enzyme activity of acetyl cholinesterase (AChE) Relationship. It was accomplished a triage of the parts extracts (leaves, stems, branches, stem bark and heartwood) of the species Simarouba Versicolor by the Ellman test. The ethanol extract of stem bark showed high inhibition of AChE, from this extract, the chloroform fraction and ethyl acetate were identified as being responsible for the inhibition of the enzyme. The chemical prospect of the chloroform fraction resulted in the isolation of three compounds, a mixture of steroid β-sitosterol and stigma sterol, a quassinoid, the 11-acetylamarolide and the alkaloid 4.5-dimetoxicantin-6-one. In the ethyl acetate fraction it was isolated the 3-β-O-β-D-glucopyranosyl sitosterol. The Structure determination of these compounds was performed by spectroscopic analysis through the methods of IR, MS, RMN1H and 13C-BB using uni and bidimensional techniques and by comparison with the data reported in the literature. In qualitative analysis of the AChE inhibition the extracts and isolated constituents 11- acetylamarolide and 4.5-dimetoxicantin-6-one showed good results. The extracts also showed cytotoxic activity in three tumor lines tested.
2

Studies Toward Syntheses of Chaparrinone and Polyandrane

Yang, Dexi 12 September 2008 (has links)
No description available.
3

Tau-Path Test - A Nonparametric Test For Testing Unspecified Subpopulation Monotone Association

Yu, Li January 2009 (has links)
No description available.

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