Data/hora: 01/06/2024 08:20:52

Provedor de dados: | 56
País: | Brazil
Título: | Antibacterial activity of indole alkaloids from Aspidosperma ramiflorum
Autores: | Tanaka,J.C.A.; Silva,C.C. da; Oliveira,A.J.B. de; Nakamura,C.V.; Dias Filho,B.P.
Data: | 2006-03-01
Ano: | 2006
Palavras-chave: | Aspidosperma ramiflorum; Antibacterial activity; Monoterpenoid indole alkaloids; Ramiflorines A and B.
Resumo: | We evaluated the antibacterial activities of the crude methanol extract, fractions (I-V) obtained after acid-base extraction and pure compounds from the stem bark of Aspidosperma ramiflorum. The minimum inhibitory concentration (MIC) was determined by the microdilution technique in Mueller-Hinton broth. Inoculates were prepared in this medium from 24-h broth cultures of bacteria (10(7) CFU/mL). Microtiter plates were incubated at 37ºC and the MICs were recorded after 24 h of incubation. Two susceptibility endpoints were recorded for each isolate. The crude methanol extract presented moderate activity against the Gram-positive bacteria B. subtilis (MIC = 250 µg/mL) and S. aureus (MIC = 500 µg/mL), and was inactive against the Gram-negative bacteria E. coli and P. aeruginosa (MIC &gt; 1000 µg/mL). Fractions I and II were inactive against standard strains at concentrations of &lt;=1000 µg/mL and fraction III displayed moderate antibacterial activity against B. subtilis (MIC = 500 µg/mL) and S. aureus (MIC = 250 µg/mL). Fraction IV showed high activity against B. subtilis and S. aureus (MIC = 15.6 µg/mL) and moderate activity against E. coli and P. aeruginosa (MIC = 250 µg/mL). Fraction V presented high activity against B. subtilis (MIC = 15.6 µg/mL) and S. aureus (MIC = 31.3 µg/mL) and was inactive against Gram-negative bacteria (MIC &gt; 1000 µg/mL). Fractions III, IV and V were then submitted to bioassay-guided fractionation by silica gel column chromatography, yielding individual purified ramiflorines A and B. Both ramiflorines showed significant activity against S. aureus (MIC = 25 µg/mL) and E. faecalis (MIC = 50 µg/mL), with EC50 of 8 and 2.5 µg/mL for ramiflorines A and B, respectively, against S. aureus. These results are promising, showing that these compounds are biologically active against Gram-positive bacteria.
Tipo: | Info:eu-repo/semantics/other
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000300009
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2006000300009
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.39 n.3 2006
Fonte: | info:eu-repo/semantics/openAccess