RESUMO
A new furostane steroidal saponin was isolated from the leaves of Agave angustifolia var. marginata. On the basis of chemical conversions and spectroscopic analyses, its structure was established as 3-[O-ß-d-glucopyranosyl-(1â3)-O-ß-d-glucopyranosyl-(1â3)-O]-[O-6-deoxy-α-l-mannopyranosyl-(1â4)-ß-d-xylopyranosyl-(1â2)-O-ß-d-glucopyranosyl-(1â4)-ß-d-galactopyranosyl)oxy]-(3ß,5α,22α,25R)-26-(ß-d-glucopyranosyloxy)-22-methoxy-furostane (1). Results of preliminary biological investigations indicated that compound 1 showed significant protective effects against induced gastric ulcers using in vivo experimental models and demonstrated negligible toxicity on membrane integrity in the in vitro assays.
Assuntos
Agave/química , Antiulcerosos/farmacologia , Saponinas/farmacologia , Úlcera Gástrica/tratamento farmacológico , Animais , Antiulcerosos/química , Antiulcerosos/isolamento & purificação , Permeabilidade da Membrana Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Masculino , Camundongos , Estrutura Molecular , Folhas de Planta/química , Saponinas/química , Saponinas/isolamento & purificação , Relação Estrutura-AtividadeRESUMO
As part of our search of bioactive saponins from Brazilian plants, phytochemical study of the seeds of Inga laurina led to the isolation of a new complex triterpenoid saponin, named ingasaponin. It is the first saponin isolated from a species of Inga genus. It was isolated by using chromatographic methods and its structural elucidation was performed using detailed analyses of (1)H and (13)C NMR spectra including 2D-NMR spectroscopic techniques and chemical conversions. Its structure was established as 21-[[(2E,6S)-6-[[6-deoxy-4-O-[(2E,6S)-6-[(ß-D-glucopyranosyl)oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]-[(ß-D-glucopyranosyl)oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]-[(ß-D-glucopyranosyl)oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]-[(ß-D-glucopyranosyl)oxy]-2-(hydroxymethyl)-6-methyl-1-oxo-2,7-octadienyl]oxy]-16-hydroxy-3-[[O-ß-D-xylopyranosyl-(1 â 2)-O-α-L-arabinopyranosyl-(1 â 6)-2-(acetylamino)-2-deoxy-ß-D-glucopyranosyl]oxy]-(3ß,16α,21ß)-olean-12-en-28-oic acid O-α-L-arabinofuranosyl-(1 â 4)-O-[ß-D-glucopyranosyl-(1 â 3)]-O-6-deoxy-α-L-mannopyranosyl-(1 â 2)-ß-D-glucopyranosyl ester (1). The hemolytic potential of 1 was evaluated using in vitro assays, and its adjuvant activity on the cellular immune response against ovalbumin antigen was investigated using in vivo models.