Data/hora: 07/06/2024 17:13:50

Provedor de dados: 	Brazilian Archives of Biology and Technology	
País: 	Brazil	
Título: 	An evaluation of antibacterial activities of Psidium guajava (L.)	
Autores: 	Sanches,Neviton Rogério; Garcia Cortez,Diógenes Aparício; Schiavini,Michelle Simone; Nakamura,Celso Vataru; Dias Filho,Benedito Prado.	
Data: 	2005-05-01	
Ano: 	2005	
Palavras-chave: 	Psidium guajava; Antibacterial activities; Flavonoids; Alpha- and beta-amyrin; Beta-sitosterol.	
Resumo: 	The present study was designated to evaluate the antibacterial activities of aqueous and ethanol:water extracts from leaves, roots and stem bark of Psidium guajava L. The antibacterial activities of the extracts against bacteria were tested by using both microdilution assay. The aqueous extracts of P. guajava leaves, roots and stem bark were active against the gram-positive bacteria Staphylococcus aureus (MICs=500, 125 and 250 µg/ml, respectively) and Bacillus subtilis (MICs=500 µg/ml), and virtually inactive against the gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa (MICs &gt;1000 µg/ml). The ethanol:water extracts showed higher antimicrobial activity as compared to aqueous extracts. Based on this finding, the ethanol:water extract of P. guajava leaves was fractionated on silica gel column chromatography in a bioassay-guided fractionation affording flavonoid mixture, triterpenes (alpha- and beta-amyrin) and sterol (beta-sitosterol). Flavonoid mixture showed good activity on S. aureus with MIC of 25 µg/ml. beta-sitosterol was inactive for all the bacteria tested.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000300014	
Editor: 	Instituto de Tecnologia do Paraná - Tecpar	
Relação: 	10.1590/S1516-89132005000300014	
Formato: 	text/html	
Fonte: 	Brazilian Archives of Biology and Technology  v.48 n.3 2005	
Fonte: 	info:eu-repo/semantics/openAccess