Um novo biflavonol denominado chimarrosídeo (1) e oito flavonóis glicosilados adicionais (2-9) foram isolados das folhas de Chimarrhis turbinata. Suas estruturas foram elucidadas com base nos dados dos experimentos de RMN 1D e 2D, como: 3-O-rutinosilquercetina (2), 3-O-rutinosil-kaempferol (3), 3-O-galactopiranosil-(6->1)-ramnopiranosil kaempferol (4), 3-O-beta-galactopiranosil-(6->1)-alfa-ramnopiranosil-quercetina (5), 6-hidroxirutina (6), 3-O-galactopiranosil-kaempferol (7), 3-O-glucopiranosil-kaempferol (8) e 3-O-ramnopiranosil-(6->1)-glucopiranosil-(4 ->1)-ramnopiranosil-kaempferol (9). Adicionalmente, a catequina (10) e a procianidina B-3 (catequina-(4<FONT FACE=Symbol>a®</FONT>8)-catequina) (11) também foram isoladas. O extrato bruto, frações e compostos isolados foram avaliados quanto às suas propriedades antioxidantes no teste em CCD aspergida com solução de beta-caroteno, e teste espectrofotométrico utilizando o radical livre 1,1-difenil-2-picrilidrazila (DPPH). Os flavonóides 2, 5, 6, 10 e 11 apresentaram forte atividade antioxidante quando comparados com os padrões BHT e rutina.
A new biflavonol, named chimarrhoside (1), and eight known flavonol glycosides (2-9), were isolated from the leaves of Chimarrhis turbinata. Their structures were established on the basis of 1D and 2D NMR experiments as quercetin-3-O-rutinoside (2), kaempferol-3-O-rutinoside (3), kaempferol-3-O-alpha-L-rhamnopyranosyl-(1->6)- beta-D-galactopyranoside (4), quercetin-3-O-alpha-L-rhamnopyranosyl-(1->6)- beta-D-galactopyranoside (5), 6-hydroxy-rutin (6), kaempferol-3-O-D-galactopyranoside (7), kaempferol-3-O-D-glucopyranoside (8) and kaempferol-3-O-alpha-L-rhamnopyranosyl-(1->6)- alpha-L-rhamnopyranosyl-(1->4)-beta-D-glucopyranoside (9). In addition, catechin (10) and catechin-(4<FONT FACE=Symbol>a®</FONT>8)-catechin-procyanidin B-3) (11) were isolated. The crude extract, fractions and isolated compounds were evaluated for their antioxidative properties using an autographic assay based on beta-carotene bleaching on TLC plates, and spectrophotometric detection by reduction of the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical. Flavonoids 2, 5, 6, 10 and 11 displayed strong free radical scavenging activity, when compared with the standards BHT and rutin.