FAMED – Faculdade de Medicina
URI permanente desta comunidadehttps://rihomolog.furg.br/handle/1/2422
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5 resultados
Resultados da Pesquisa
- ItemPreparative Isolation of Antimycobacterial Shoreic Acid from Cabralea canjerana by High Speed Countercurrent Chromatography(2008) Leitão, Gilda Guimarães; Abreu, Lisandra Ferreira de; Costa, Fernanda das Neves; Brum, Thiago Braga; Soares, Daniela Fernandes Ramos; Silva, Pedro Eduardo Almeida da; Lourenço, Maria Cristina da Silva; Leitão, Suzana GuimarãesHigh speed countercurrent chromatography (HSCCC) was used to isolate the dammarane type triterpene shoreic acid from the dichloromethane extract of leaves of Cabralea canjerana, which showed activity against Mycobacterium tuberculosis. A preparative scale-up of the process was also developed.
- ItemThe activity of flavones and oleanolic acid from Lippia lacunosa against susceptible and resistant Mycobacterium tuberculosis strains(2011) Duarte, Aline Castellar; Coelho, Tatiane Silveira; Silva, Pedro Eduardo Almeida da; Soares, Daniela Fernandes Ramos; Lourenço, Maria Cristina da Silva; Lage, Celso Luiz Salgueiro; Julião, Lisieux de Santana; Barbosa, Ymira Albuquerque Gálico; Leitão, Suzana GuimarãesTuberculosis (TB), caused by Mycobacterium tuberculosis, is the world’s number one killer among infectious diseases. The search for new natural products that can act as drugs against TB has received increased attention during the last years. In this work we describe the isolation and identification of the active antimycobacterial principles of the dichloromethane extract from Lippia lacunosa Mart. & Schauer, Verbenaceae. Compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis (susceptible and rifampicin resistant strain) using a redox bioassay. From the dichloromethane extract of L. lacunosa leaves, seven methoxy-flavones named cirsimaritin (1), eupatilin (2), eupatorin (3), salvigenin (4), 3′-O-methyl-eupatorin (5), 3′,7-dimethoxy-5,6,4′- trihydroxyflavone (6), and 7′-O-methylapigenin (7), and one triterpene, named oleanolic acid (8), were isolated. All compounds were found to display antimycobacterial activity against susceptible strain, with MIC ranging from 25 to 200 μg/mL. None of them was active against rifampicin resistant strain. This is the first report in the antimycobacterial activity of 6-substituted flavones, as well as the first report of the occurrence of these substances in L. lacunosa.
- ItemSynthesis and in vitro antimycobacterial activity of 3-substituted 5-hydroxy-5-trifluoro[chloro]methyl-4,5-dihydro-1H-1-(isonicotinoyl) pyrazoles(2008) Silva, Pedro Eduardo Almeida da; Soares, Daniela Fernandes Ramos; Bonacorso, Helio Gauze; Iglesia, Agustina de la; Oliveira, Marli Redin; Coelho, Tatiane Silveira; Navarini, Jussara; Morbidoni, Hector; Zanatta, Nilo; Martins, Marcos Antonio PintoA series of 3-substituted 5-hydroxy-5-trifluoro[chloro]methyl-1H-1-isonicotinoyl-4,5-dihydropyrazoles (2a–i) were synthesised by the cyclocondensation reaction of 4-methoxy-1,1,1-trifluoro[chloro]-4 (substituted)-alk-3-en-2-ones (1a–i) and isoniazid (INH). Their in vitro antimicrobial activity was tested against INH-susceptible Mycobacterium tuberculosis H37Rv, INH-resistant clinical M. tuberculosis isolates and non-tuberculous mycobacteria. Amongst the synthesised compounds, 5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-1 (isonicotinoyl)- pyrazole (2a) and 5-hydroxy-3-(4-methylphenyl)-5-trifluoromethyl-4,5-dihydro-1H-1-(isonicotinoyl) pyrazole (2d) were found to be the two most active agents against susceptible M. tuberculosis and several INH-resistant strains. The compound 3-(2-furyl)-5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-1-(isonicotinoyl)pyrazole (2f) was active against all the INH-resistant strains regardless of the genetic background at concentrations two- to four-fold its minimum inhibitory concentration against M. tuberculosis H37Rv. These compounds were inhibitors of mycolic acid biosynthesis, in agreement with the utilisation of the INH scaffold for their design. Interestingly, the most active compound against M. tuberculosis, 5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-1-(isonicotinoyl)-pyrazole (2a),was even more potent than INH against non-tuberculous mycobacteria.
- ItemScreening of Central and South American plant extracts for antimycobacterial activity by the alamar blue test(2006) Leitão, Suzana Guimarães; Castro, Oscar; Fonseca, Eduardo Nunes da; Julião, Lisieux de Santana; Tavares, Eliana Schwartz; Leo, Rodrigo Ribeiro Tarjano; Vieira, Ricardo Cardoso; Oliveira, Danilo Ribeiro de; Leitão, Gilda Guimarães; Martino, Virginia; Sulsen, Valeria; Barbosa, Ymira Albuquerque Gálico; Pinheiro, Diva de Paula Gondim; Silva, Pedro Eduardo Almeida da; Teixeira, Dulcineia Furtado; Neves Junior, Ivan; Lourenço, Maria Cristina da SilvaQuarenta e oito extratos brutos etanólicos e frações (em hexano, diclorometano, acetato de etila e n-butanol) de dez plantas brasileiras pertencentes às famílias Leguminosae, Monimiaceae e Verbenaceae; uma da Costa Rica (Verbenaceae) e uma da Argentina (Verbenaceae) foram ensaiados para verifi cação da atividade anti-micobacteriana contra Mycobacterium tuberculosis (ATCC-27294 H37Rv), pelo teste do Alamar Blue, a uma concentração fi xa de 100 μg/mL. Dentre os quarenta e oito extratos e frações estudados, sete mostraram-se ativos na concentração ensaiada - frações em hexano e diclorometano de folhas de Lantana trifolia, extrato em metanol:água, 1:1 de cascas de Vitex cooperi, frações em hexano e diclorometano de folhas de Lippia lacunosa e de Lippia rotundifolia, sendo que todas essas plantas pertencem à família Verbenaceae.
- ItemAtividade antimicobacteriana de extratos vegetais frente a mycobacterium fortuitum e mycobacterium malmoense(2008) Fonseca, Tesiê Leopoldo; Groll, Andrea Von; Leitão, Gilda Guimarães; Scaini, Carlos James; Soares, Daniela Fernandes Ramos; Silva, Pedro Eduardo Almeida daAs micobactérias não-tuberculosas são espécies ambientais com crescente relevância clínica, por sua relação com diversos tipos de infecções. Geralmente, apresentam maior resistência intrínseca aos antimicobacterianos convencionais, impulsionando assim a busca de novas alternativas farmacológicas, como as obtidas de fontes naturais. Este estudo avaliou a atividade de clássicos antituberculosos, como estreptomicina (SMR), etambutol (EMB), isoniazida (INH) e rifampicina (RIF), bem como extratos vegetais oriundos da Mata Atlântica (Brasil) frente ao Mycobacterium fortuitum e Mycobacterium malmoense. Foram observadas as seguintes concentrações mínimas inibitórias (CMI) para o M. fortuitum: EMB = 16μg/mL; SMR = 4μg/mL; INH e RIF 1μg/mL; extrato bruto Plathymenia foliolosa = 200μg/mL. Já para o M. malmoense, as CMI encontradas foram: SMR = 4μg/mL; INH = 1μg/mL e RIF = 0,25μg/mL. O EMB não inibiu o crescimento bacteriano desta espécie. Os compostos naturais ativos contra o M. malmoense foram os extratos Siparuna arianeae, Cedrela fissilis e Peschiera affinis, que apresentaram CMI de 200μg/mL, enquanto a CMI de Ficus gomelleria foi de 100μg/mL.