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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

Fitoquímica, quimiossistemática e busca de novos fármacos antichagásicos e antileishmanioses: estudo de Raputia praetermissa (Rutaceae). / Phytochemistry, chemosystematic and searching of new antichagasic and antileishmaniasis drugs: study of Raputia praetermissa (Rutaceae).

Rosas, Lisandra Vieira 31 August 2005 (has links)
Made available in DSpace on 2016-06-02T20:34:03Z (GMT). No. of bitstreams: 1 TeseLVR.pdf: 6988214 bytes, checksum: d780cb227a0bf1454902b195e898d753 (MD5) Previous issue date: 2005-08-31 / Universidade Federal de Minas Gerais / Raputia praetermissa (Engler) Emmerich is a tree found only in the Forest Reserve Adolpho Ducke, Amazonas, Brazil. The genus Raputia was originally described by Engler and many species were included in this genus, but in 1978, Emmerich proposed three new genera Neoraputia, Raputiarana e Sigmathantus in order to accommodate six species, four belonging to the genus Raputia, which is assigned into the tribe Cuspariae, and two that had not been described yet. From our knowledge no previous phytochemical work has been reported on Raputia. Therefore, this study describes phytochemical and chemosystematic investigation and the search of compounds with trypanocidal and leishmanicidal activity from roots of R. praetermissa. The phytochemical work involved crude extract preparation, followed by fractionation and isolation of compounds thorough different chromatography methods. Spectroscopic analyses permitted the identification of them and the results showed the presence of new substances in addition to those isolated previously. Here we reported the isolation and identification of the new compounds: two new limonoids, 11β,19α-dihydroxi-7- deoxo-7-acetoxy-ichangin e 11β,19α-oxide-7-deacetoxy-7-hidroxy-ichangin, two new prenylated indoles alkaloids, 5-[(3 -dimethylalil-4 -methylidene)-2 -tetrahidrofuran-2 - il]-indol e 5-[(4 -carbomethoxy)-furan-2 -il]-indol and a new bisindol alkaloid, 5 ,6 -[5- methyl-5(7-indol-5 -il-etene-6,7-diil)-3(1-methylprop-2-en-2-il)]-ciclopentane-5 ,6 -diilindol. The following known substances were also obtained: T-cadinol, β-sitosterol, stigmasterol, campesterol, 3-[2 ,6 -dimethoxy-6 ,6 -dimethylpyrano(2 ,3 :3 ,4 ) phenyl]-methylpropionate, 3-oxo-cadinol, lanosta-7,24-dien-21-oic acid-3-oxo, dictamine, γ-fagarine, 1-methyl-4-methoxy-2-quinolone, tricoccin S13 acetate, 6- formylindol. Our results showed that the chemical classes isolated from R. praetermissa roots are common to the Rutaceae family, but the prenylated indol alkaloids are not. These compounds are new classes of prenylated indol alkaloids. However, all isolated compounds confirm the assigned it into the tribe Cuspariae. In addition, the compounds were evaluated for: a) in vitro biological activity against trypanosomastigotes forms of Trypanosoma cruzi and amastigotes forms of Leishmania braziliensis; b) enzymatic inhibitory activity on glyceraldehydes- XXXII phospato-dehidrogenase (gGAPDH) of T. cruzi and enzymatic inhibitory activity on adenine-phosphoribosyl-transferase (APRT) of Leishmania tarentolae. None of isolated substances were promising against T. cruzi in vitro test as well as in enzymatic experimental models (gGAPDH e APRT) from which they not showed enzymatic inhibitory activity. Conversely, the T-cadinol was active against L. braziliensis and results in DL50 44 µM. / XXIX Raputia praetermissa (Engler) Emmerich é uma arvoreta encontrada somente na Reserva Florestal Adolpho Ducke, Amazonas, Brasil. O gênero Raputia foi originalmente descrito por Engler, onde várias espécies foram incluídas, mas em 1978, Emmerich propôs dividi-lo em três novos gêneros, Neoraputia, Raputiarana e Sigmathantus com o objetivo de acomodar seis espécies, quatro destas pertencentes a Raputia (incluída na tribo Cuspariae) e duas que ainda não haviam sido descritas. Atualmente este gênero possui 11 espécies. Não há relatos de estudos fitoquímicos em Raputia. Este trabalho descreve o estudo fitoquímico e quimiossistemático e a busca de compostos tripanocida e leishmanicida na raiz de R. praetermissa. O estudo fitoquímico envolveu desde a preparação dos extratos brutos, seguidos pelo fracionamento e isolamento dos compostos através de diferentes métodos cromatográficos. As análises espectroscópicas permitiram a identificação de substâncias conhecidas e inéditas. Neste são descritos o isolamento e identificação de dois limonóides inéditos, 11β,19α-dihidroxi-7-deoxo-7-acetoxi-ichangina e 11β,19α-óxido-7-deacetoxi-7- hidroxi-ichangina, dois alcalóides indólicos prenilados inéditos, 5-[(3 -dimetilalil-4 - metilideno)-2 -tetraidrofurano-2 -il]-indol e 5-[(4 -carbometoxi)-furano-2 -il]-indol, e um alcalóide bisindol também inédito, 5 ,6 -[5-metil-5(7-indol-5 -il-eteno-6,7-diil)-3(1- metilprop-2-en-2-il)]-ciclopentano-5 ,6 -diil-indol, e as substâncias conhecidas, Tcadinol, β-sitosterol, estigmasterol, campesterol, 3-[2 ,6 -dimetoxi-6 ,6 - dimetilpirano(2 ,3 :3 ,4 ) fenil] propianato de metila, 3-oxo-T-cadinol, ácido 3- oxotirucala-7,24-dien-21-óico, dictamina, γ-fagarina, 1-metil-4-metoxi-2-quinolona, acetato de tricocina S13, 6-formilindol. Nossos resultados mostram que as classes químicas isoladas são comuns na família Rutaceae, exceto os indólicos prenilados que pertencem a uma nova classe de indólicos. Contudo, todas as substâncias isoladas confirmam o posicionamento de Raputia na tribo Cuspariae. Os compostos isolados foram avaliados quanto: a) Atividade biológica in vitro contra as formas tripomastigotas de Trypanosoma cruzi e amastigotas de Leishmania braziliensis; b) Atividade enzimática inibitória em gGAPDH (Gliceraldeído-3-fosfato-desidrogenase) do T. cruzi e em APRT (adenina-fosforribosil-transferase) de Leishmania tarentolae. Nenhuma das substâncias isoladas foi promissora no teste in vitro contra T. cruzi. No modelo experimental enzimático (gGAPDH e APRT) nenhum composto mostrou atividade inibitória promissora. Por outro lado, o T-cadinol foi ativo contra L. braziliensis resultando em uma DL50 de 44 µM.

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