RESUMO
Angiogenesis, the growth of new blood vessels from the pre-existing vasculature is of physiological and pathological importance. Substantial data over the last decade has implicated uncontrolled angiogenesis with various pathological states. Vascular endothelial growth factors (VEGFs) play a critical role in its regulation, and have become one of the most interesting anti-angiogenesis targets. We have investigated the anti-angiogenic potential of plant extracts in a preliminary ELISA screening. The n-BuOH extract obtained from the leaves of Monnina obtusifolia (Polygalaceae) demonstrated an inhibition of VEGF-A or Placental Growth Factor interaction with Flt-1 (VEGF receptor 1), with an inhibition over 50% in particular for VEGF-A/Flt-1 interaction at a concentration of 500 µg/mL. Successively fractionation of the bioactive n-BuOH extracts of M. obtusifolia aerial parts led to the isolation of six new compounds, 1-O-(4-hydroxy-2-methylene-butanoic acid)-6-O-ß-D-(4-hydroxy-2-methylene-butanoyl)-glucopyranose (1), 1-O-(isopentenyl)-6-O-ß-D-(4-hydroxy-2-methylene-butanoyl)-glucopyranose (2), 1-O-(4-hydroxy-2-methylene-butanoic acid)-6-O-ß-D-(isovaleroyl)-glucopyranose (3), 1-O-(3-methylbut-3enyl)-6-O-ß-D-(isovaleroyl)-glucopyranose (4), two new sucrose esters, 3,4-O-ß-D-di-feruloyl-fructofuranosyl-6-O-α-D-(p-coumaroyl)-glucopyranoside (5), and 3,4-O-ß-D-di-feruloyl-fructofuranosyl-6-O-α-D-(caffeoyl)-glucopyranoside (6), together with known flavonoids. Their structures were established on the basis of detailed spectral analysis. Since none of the isolated compounds showed a relevant inhibition of VEGFs, the biological activity observed for the butanolic extract might be due to the presence of a combination of compounds acting synergistically.
Assuntos
Inibidores da Angiogênese/farmacologia , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Extratos Vegetais/farmacologia , Polygalaceae/química , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Inibidores da Angiogênese/química , Inibidores da Angiogênese/isolamento & purificação , Sinergismo Farmacológico , Flavonoides/química , Glicosídeos/química , Estrutura Molecular , Extratos Vegetais/química , Folhas de PlantaRESUMO
An essential oil, obtained by steam distillation of Clinopodium tomentosum (Kunth) Govaerts (Lamiaceae), collected in Ecuador, was analyzed by gas chromatography-olfactometry (GC-O) and GC-MS techniques. To our knowledge, the composition of this essential oil is described here for the first time, both from the chemical and olfactometric viewpoints. A preliminary analysis by GC-MS and using Kovats' retention indexes, lead to characterize and quantify the oil constituents, while GC-O was then applied for the identification of the main odorants. By the incremental dilution method (AEDA, CHARM Analysis), applied to the GC-O technique, the flavor dilution (FD) chromatogram was obtained. In order to calculate the TOC values of the main odorants, the relationship between the odorant concentration at the sniffing port and that one in the injected solution was established. This relationship was calculated by comparing the injected amount with the TOC value of a reference compound (limonene), obtained by dynamic dilution olfactometry. A good agreement was found between calculated and measured TOC values of few odorants.
Assuntos
Cromatografia Gasosa/métodos , Lamiaceae/química , Odorantes/análise , Óleos Voláteis/análise , Óleos de Plantas/análise , Cromatografia Gasosa-Espectrometria de Massas , Técnicas de Diluição do Indicador , Óleos Voláteis/química , Óleos de Plantas/química , Reprodutibilidade dos TestesRESUMO
Four enyne derivatives (1-4) and quercitrin were isolated during a bioassay-guided chromatographic separation of a methanolic extract of Erigeron apiculatus. Matricarialactone (1) and lachnophyllumlactone (2) showed a high fungitoxic activity against Pyricularia oryzae. Matricaria acid methyl ester (3) and lachnophyllum acid methyl ester (4) were, instead, less active.
Assuntos
Antifúngicos/farmacologia , Erigeron , Fitoterapia , Extratos Vegetais/farmacologia , Antifúngicos/administração & dosagem , Antifúngicos/uso terapêutico , Humanos , Testes de Sensibilidade Microbiana , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêuticoRESUMO
El senecio canescens Humb., conocido vulgarmente como "orejas de conejo", es usado en la medicina popular para curar infecciones, dolores de cabeza y reumatismos. La investigación de las partes aéreas y de las raíces condujo a la determinación de compuestos furanoeremofilanos, entre los cuales se elució el primer furanoeremofilano hidroperóxido natural y dos nuevos derivados de la cacalohastina, uno de los cuales es un dimero. La fracción volatil fue analizada por GC-MS.
