Free radical scavenging activity of Kielmeyera variabilis (Clusiaceae).
Molecules
; 18(2): 2376-85, 2013 Feb 19.
Article
em En
| MEDLINE
| ID: mdl-23429348
ABSTRACT
As part of our ongoing research on antioxidant agents from Brazilian flora, we screened the free radical scavenging activity of two extracts and eight fractions of Kielmeyera variabilis (Clusiaceae) using DPPH· (2,2-diphenyl-1-picrylhydrazyl-hydrate) and ABTS·+ [2,2'-azinobis(3-ethylenebenzothiazoline-6-sulfonic acid)] colorimetric assays. The ethyl acetate and n-butanol fractions of the leaves of K. variabilis displayed the strongest activity (IC50 of 3.5 ± 0.3 and 4.4 ± 0.2 µg mL⻹ for DPPH· and 6.6 ± 0.4 and 3.1 ± 0.1 µg mL⻹ for ABTS·+, respectively). Chromatographic fractionation of the most potent fractions led to identification of three flavonols with previously described antioxidant activity, quercitrin (1), quercetin-3-O-ß-glucoside (3), and quercetin-3-O-ß-galactoside (4), and of one biflavone, podocarpusflavone A (2). This is the first time that the presence of these flavonoids in Kielmeyera variabilis has been reported.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sequestradores de Radicais Livres
/
Clusiaceae
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article