New biflavonoid and other flavonoids from the leaves of Chimarrhis turbinata and their antioxidant activities

Autor(es)

Carmem L. Cardoso ^[1] ; Dulce H. S. Silva ^[2] ; Ian Castro-Gamboa ^[3] ; Vanderlan da S. Bolzani ^[4]

Afiliação do(s) autor(es)

^[1] Universidade Estadual Paulista. Instituto de Química - Brasil

^[2] Universidade Estadual Paulista. Instituto de Química - Brasil

^[3] Universidade Estadual Paulista. Instituto de Química - Brasil

^[4] Universidade Estadual Paulista. Instituto de Química - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Brazilian Chemical Society; v. 16, p. 1353-1359, 2005-11-00.
• Área do conhecimento: Ciências Exatas e da Terra - Química
• Assunto(s): Rubiaceae Biflavonoides Flavonoides Radicais livres beta Caroteno

Resumo

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. (AU)

• Processo FAPESP: 03/02176-7 - Conservação e uso sustentável da diversidade do Cerrado e da Mata Atlântica: diversidade química e prospecção de medicamentos potenciais - fase II
• Beneficiário: Vanderlan da Silva Bolzani
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Temático