RESUMO
The free radical scavenging activity of methanolic, ethanolic and aqueous extracts from Ginkgo biloba leaves, has been determined by EPR (electron paramagnetic resonance) using the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging method. The investigation has also included selected constituents of G. biloba leaves, protocatechuic and p-coumaric acids, quercetin, rutin, isoginkgetin and (+)-catechin.
Assuntos
Sequestradores de Radicais Livres/farmacologia , Ginkgo biloba , Fitoterapia , Extratos Vegetais/farmacologia , Compostos de Bifenilo , Espectroscopia de Ressonância de Spin Eletrônica , Sequestradores de Radicais Livres/administração & dosagem , Sequestradores de Radicais Livres/uso terapêutico , Humanos , Picratos , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Folhas de PlantaRESUMO
The presence of phenolic acids in the leaves, roots and seed testas of Ginkgo biloba L. (Ginkgoaceae) was analyzed. Seven free and liberated by hydrolysis phenolic acids were identified by chromatographic (TLC) and spectral (UV) methods as protocatechuic, p-hydroxybenzoic, vanillic, caffeic, p-coumaric, ferulic and chlorogenic acids.
Assuntos
Fenóis/isolamento & purificação , Plantas Medicinais/química , Hidrólise , Fenóis/química , Espectrofotometria UltravioletaRESUMO
HPLC was applied to the quantitative assay of seven free phenolic acids from the leaves, roots and seed testas of Ginkgo biloba L. (Ginkgoaceae). The concentration of the free phenolic acids amounted to: 19.693 micrograms/g of fresh leaves, 345.321 micrograms/g of roots and 2.708 micrograms/g of testas: protocatechuic acid is a dominant one. The concentration of the phenolic acids liberated by acid-mediated and alkaline hydrolysis was determined as well.
Assuntos
Fenóis/análise , Plantas Medicinais/química , Cromatografia Líquida de Alta Pressão , Hidrólise , Espectrofotometria UltravioletaRESUMO
The content of flavonoids, total phenolic acids and free radicals has been determined respectively by Christ-Muller method, HPLC and EPR in leaves of Ginkgo biloba L. during the vegetative cycle. The relationship between these parameters has been discussed.
Assuntos
Flavonoides/análise , Ginkgo biloba/química , Fenóis/análise , Cromatografia em Camada Fina , Cobre/análise , Radicais Livres/análise , Ginkgo biloba/crescimento & desenvolvimento , Folhas de Planta/químicaRESUMO
Extracts from propolis have been investigated for cytostatic activity in vitro, by method of tissue culture on human KB and HeLa cell lines. Diethyl ether extract (DEEP) sowed the greatest activity and therefore it was further fractionated. Secondary DEEP fractions obtained by extraction with BuOH (ED50 = 2.6 micrograms/ml) and AcOEt (ED50 = 3.3 micrograms/ml) have been qualified to further in vivo studies.