RESUMO
A new steroidal saponin, 3-{(O-6-deoxy-a-L-mannopyranosyl-(1 --> 4)-O-beta-D-glucopyranosyl-(1 --> 3)-O-[O-beta-D-glucopyranosyl-(1 --> 3)-beta-D-glucopyranosyl-(1 --> 2)]-O-beta-D-glucopyranosyl-(1 --> 4)-beta-D-galactopyranosyl)oxy}-6-hydroxy-(3beta,5alpha,6alpha,25R)-spirostan-12-one, was isolated from Agave brittoniana Trel. The structure was determined by extensive NMR spectroscopy studies and chemical conversions. Its effects on the Na+-ATPase and (Na+ + K+)-ATPase activities of the proximal tubule from pig kidney were evaluated. It was observed that this steroidal saponin exerts a biphasic effect on the Na+-ATPase activity. It is concluded that the effect of the aqueous extract as a diuretic is due, at least in part, to the action of saponin on the ouabain-insensitive Na+-ATPase.
Assuntos
Agave/química , Saponinas/química , Saponinas/farmacologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Esteroides/química , Esteroides/farmacologia , Animais , Configuração de Carboidratos , Sequência de Carboidratos , Membrana Celular/enzimologia , Túbulos Renais/enzimologia , Cinética , Metilação , Modelos Moleculares , Dados de Sequência Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Folhas de Planta/química , Saponinas/isolamento & purificação , Sódio/farmacologia , ATPase Trocadora de Sódio-Potássio/efeitos dos fármacos , Esteroides/isolamento & purificação , SuínosRESUMO
A polysaccharide, an alpha-D-glucan with an apparent molecular weight of 6.85 x 10(4), called PSa glucan, was isolated from fresh seeds of Sorghum arundinaceum by fractionation on Sephacryl S-300 HR and Sephadex G-25. Chemical and spectroscopic studies indicated that it has a highly branched glucan type structure composed of alpha-(1-->4) linked D-glucopyranose residues with (1-->3), (1-->6) branching points, and a significant amount of alpha-(1-->6) branching to alpha-(1-->3) linked D-glucopyranose residues. The anti-inflammatory activity of the polysaccharide was performed using the capillary permeability assay.
Assuntos
Anti-Inflamatórios/química , Grão Comestível/química , Polissacarídeos/química , Sementes/química , Animais , Anti-Inflamatórios/farmacologia , Configuração de Carboidratos , Sequência de Carboidratos , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Metilação , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Oligossacarídeos/química , Oligossacarídeos/isolamento & purificação , Extratos Vegetais/química , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , EsteroidesRESUMO
A new steroidal saponin was isolated from the leaves of Agave attenuata Salm-Dyck. Its structure was established as (3beta,5beta,22alpha,25S)-26-(beta-D-glucopyranosyloxy)-22-methoxyfurostan-3-yl O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->3)]-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside. The structural identification was performed using detailed analyses of 1H and 13C NMR spectra including 2D NMR spectroscopic techniques (COSY, HETCOR and COLOC) and chemical conversions. The haemolytic potential of the steroidal saponin was evaluated and the anti-inflammatory activity was performed using the capillary permeability assay.