Antioxidant activity of Maytenus imbricata Mart., Celastraceae.

A atividade antioxidante, poder redutor (RP) e a atividade coletora de radicais livres (FRS) usando 2,2-difenil- 1-picrilhidrazil (DPPH), e a concentra??o de subst?ncias fen?licas totais dos extratos e subst?ncias isoladas das folhas, caules e ra?zes de Maytenus imbricata Mart. (Celastraceae) foram avaliados. Alguns extratos, a mistura de compostos fen?licos e epicatequina mostraram alto poder redutor e atividade antioxidante (DPPH) em compara??o com o padr?o butilhidroxianisol (BHA) e ?cido g?lhico (GA) utilizados no ensaio. O extrato acetato de etila das folhas mosraram alto teor de subst?ncias fen?licas e alto poder redutor e atividade antioxidante em rela??o aos outros extratos. Este fato indica haver alguma rela??o entre a concentra??o de subst?ncias fen?licas e o poder redutor. O solvente usado no processo de extra??o influencia a composi??o qu?mica dos extratos e, consequentemente, as atividades redutoras e antioxidantes.The free radical scavenging activity (FRS) using 2,2-diphenyl-1-picrylhydrazyl (DPPH), the reducer power and the total phenolic concentration of extracts and compounds isolated from leaves, branches and roots of Maytenus imbricata Mart. (Celastraceae) were evaluated. Some extracts, a mixture of phenolic compounds (MPC) and epicatechin showed higher RP and FRS (DPPH) activities in comparison with the standard butylhydroxyanisole (BHA) and galic acid (GA) used in assays. The ethyl acetate extract from leaves showed higher total phenolic content and also higher RP and FRS (DPPH) than the other extracts. These facts indicate that there are some relations between phenolic concentration in the extract and the antioxidant activity and the reducer power. The solvent used in the extraction process influences the chemical composition of the extracts and consequently its antioxidant and reducer power activities