RESUMO
The chemical composition of Gynostemma burmanicum King ex Chakrav. was investigated for the first time in this study. Nine dammarane glycosides (1â9) were isolated from the EtOH extract of the aerial parts of G. burmanicum. Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The new compounds were 3ß,20S-dihydroxydammar-24-ene-3-O-ß-D-glucopyranosyl-20-O-[ß-D-xylopyranosyl-(1â6)-ß-D-glucopyranoside] (1), 3ß,12ß,20S-trihydroxydammar-24-ene-3-O-ß-D-xylopyranosyl-20-O-[ß-D-xylopyranosyl-(1â6)-ß-D-glucopyranoside] (2), and 12-oxo-3ß,20S-dihydroxydammar-24-ene-3-O-[ß-D-glucopyranosyl(1â2)-ß-D-glucopyranosyl]-20-O-[ß-D-xylopyranosyl-(1â6)-ß-D-glucopyranoside] (3).
Assuntos
Glicosídeos/isolamento & purificação , Gynostemma/química , Triterpenos/isolamento & purificação , Glicosídeos/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Extratos Vegetais/química , Saponinas/química , Saponinas/isolamento & purificação , Triterpenos/química , DamaranosRESUMO
A megastigmane sulphoglycoside together with three phenolic compounds were isolated from the water-soluble fraction of the pericarps of Garcinia mangostana. The structure of the new compound was determined as 4-O-sulpho-ß-d-glucopyranosyl abscisate (1) by spectroscopic data. Proanthocyanidin A2 (2) showed potent α-glucosidase inhibitory and DPPH scavenging activities with IC50 values of 3.46 and 11.6 µM, respectively.
Assuntos
Frutas/química , Garcinia/química , Ácido Abscísico/análogos & derivados , Compostos de Bifenilo , Inibidores Enzimáticos/farmacologia , Sequestradores de Radicais Livres/farmacologia , Glucosídeos , Espectroscopia de Ressonância Magnética , Norisoprenoides , Fenóis/química , Fenóis/isolamento & purificação , Picratos , Extratos Vegetais/química , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , alfa-GlucosidasesRESUMO
One new ß-carboline alkaloid 7-methoxy-(9H-ß-carbolin-1-il)-(E)-1-propenoic acid (1) together with 9-methoxycanthin-6-one (2) and 9-hydroxycanthin-6-one (3) were isolated from the hairy-root cultures of Eurycoma longifolia. The effects of these compounds on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells were investigated. Compound 1 strongly inhibited the production of NO while 2 and 3 having weak or inactive effect. Consistently, compound 1 decreased the expression of cyclooxygenase-2 and inducible nitric oxide synthase.
Assuntos
Alcaloides/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Carbolinas/farmacologia , Eurycoma/química , Alcaloides/isolamento & purificação , Animais , Anti-Inflamatórios não Esteroides/química , Carbolinas/isolamento & purificação , Inibidores de Ciclo-Oxigenase 2/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Eurycoma/citologia , Alcaloides Indólicos/isolamento & purificação , Alcaloides Indólicos/farmacologia , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/metabolismo , Raízes de Plantas/química , Raízes de Plantas/citologia , Plantas Medicinais/química , Plantas Medicinais/citologiaRESUMO
CONTEXT: A methanol extract of Cyperus rotundus L. (Cyperaceae) rhizomes showed inhibitory activity against α-glucosidase and α-amylase, two enzymes involve in carbohydrate digestion. OBJECTIVE: Identification of compounds from C. rotundus rhizomes responsible for the inhibition of α-glucosidase and α-amylase. MATERIALS AND METHODS: Compounds were identified by a phytochemical investigation using combined chromatographic and spectroscopic methods. α-glucosidase and α-amylase inhibitory activities were evaluated by in vitro enzyme inhibition assays. RESULTS: A new (2RS,3SR)-3,4',5,6,7,8-hexahydroxyflavane (1), together with three known stilbene dimers cassigarol E (2), scirpusin A (3) and B (4) were isolated. Compound 2 inhibited both α-glucosidase and α-amylase activities while the flavane 1 only showed effect on α-amylase, and compounds 3 and 4 were active on α-glucosidase. All four compounds showed significant 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. DISCUSSION: The inhibitory activities against α-amylase and α-glucosidase of the C. rotundus rhizomes were reported for the first time. Stilbene dimers are considered as potent inhibitors of α-glucosidase and promising antihyperglycemic agents. CONCLUSION: The isolated compounds may contribute to the antidiabetic property of C. rotundus.