RESUMO

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 → 2)-O-α-L-arabinopyranosyl-(1 → 6)-2-(acetylamino)-2-deoxy-ß-D-glucopyranosyl]oxy]-(3ß,16α,21ß)-olean-12-en-28-oic acid O-α-L-arabinofuranosyl-(1 → 4)-O-[ß-D-glucopyranosyl-(1 → 3)]-O-6-deoxy-α-L-mannopyranosyl-(1 → 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.

Assuntos

Adjuvantes Imunológicos/farmacologia , Fabaceae/química , Saponinas/isolamento & purificação , Triterpenos/isolamento & purificação , Adjuvantes Imunológicos/química , Adjuvantes Imunológicos/isolamento & purificação , Animais , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Masculino , Camundongos , Estrutura Molecular , Ovalbumina/administração & dosagem , Ovalbumina/imunologia , Saponinas/química , Saponinas/farmacologia , Sementes/química , Triterpenos/química , Triterpenos/farmacologia