RESUMO
The antioxidant activity of 14 compounds (1-14) isolated from the ether and butanolic extracts of the aerial parts of Ophryosporus heptanthus has been assayed using a beta-carotene bleaching method and the DPPH technique. Compounds 1 and 13 showed the most potent antioxidant activity. Their structures have been established by spectroscopic techniques (mainly NMR). Compounds 7 and 12 are new natural products, and their structures have been confirmed by chemical synthesis.
Assuntos
Antioxidantes/farmacologia , Asteraceae/química , Diterpenos/farmacologia , Flavonoides/farmacologia , Fenóis/farmacologia , Diterpenos/química , Flavonoides/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Fenóis/química , PolifenóisRESUMO
Fifty-four different extracts of nine Bolivian plants belonging to the family Asteraceae were evaluated for their radical scavenging activity by the DPPH*, NBT/hypoxanthine superoxide, and (*)OH/luminol chemiluminescence methods, and for their antioxidant activity by the beta-carotene bleaching test. The total phenolic content was also determined by the Folin-Ciocalteu method, and the oxidative stability by the Rancimat test. Both remarkably high phenolic content and radical scavenging and antioxidant activities were found mainly in the ethyl acetate fractions among the different plant extracts. Some ethyl acetate and even some defatted crude extracts exhibited activities comparable to those of commercial extracts/compounds, thus making it possible to consider some of the studied plants as a potential source of antioxidants of natural origin.
Assuntos
Antioxidantes/análise , Asteraceae/química , Sequestradores de Radicais Livres/análise , Extratos Vegetais/química , Bolívia , Hidroxianisol Butilado/análise , Medições Luminescentes , Luminol , Fenol/análise , Quercetina/análiseRESUMO
Thirty-six different extracts of six herbs and aromatic plants (fennel, common melilot, milfoil, lavandin cv. Super, spike lavender, and tarragon) were evaluated for their radical scavenging activity by the DPPH*, NBT/hypoxanthine superoxide, and *OH/luminol chemiluminescence methods, and for their antioxidant activity by the beta-carotene blenching test. The total phenolic content was also determined by the Folin-Ciocalteu method. The plant material included cultivated plants and their wastes after being distilled for essential oils. Both remarkably high phenolic content and radical scavenging activities were found for the ethyl acetate and dichloromethane fractions among the different plant extracts. In general, the distilled plant material was found to exhibit a higher phenolic content as well as antioxidant and radical scavenging activities than the nondistilled material. Ethyl acetate and dichloromethane extracts, and even some crude extract, of both distilled and nondistilled plants exhibited activities comparable to those of commercial extracts/compounds, thus making it possible to consider some of them as a potential source of antioxidants of natural origin.
Assuntos
Antioxidantes/análise , Sequestradores de Radicais Livres/análise , Extratos Vegetais/química , Acetatos , Artemisia/química , Compostos de Bifenilo , Foeniculum/química , Radicais Livres , Radical Hidroxila , Lavandula/química , Medições Luminescentes , Luminol , Região do Mediterrâneo , Cloreto de Metileno , Fenóis/análise , Picratos/química , beta Caroteno/químicaRESUMO
Three sesquiterpene lactones were isolated from Lourteigia ballotaefolia (H. B. K.). 9beta-hydroxy-atripliciolide-8- O-tiglate ( 1) was isolated for the first time from this plant and was previously reported in Conocliniopsis prasiifolia (DC) K. et R., 9beta-hydroxy-atripliciolide-8- O-(5'-acetoxytiglate) ( 2) had been already reported in this species. The minor component, 9beta-(tigloyloxy)-atripliciolide, is a new compound. The anti-inflammatory activity of compounds 1 and 2 was evaluated using the croton oil ear test in mice.
