Anti-Influenza a virus of a new oligosaccharide citric acid derivative isolated from Vigna angularis (ohwi et ohashi. var. Dainagon) Seeds

A new oligosaccharide citric acid derivative was isolated by hot aqueous extraction at 85 degrees C from Vigna angularis seeds, and it was purified using anion exchange chromatography DE-52. The structure was inferred by using UV, 1 D and 2 D NMR spectroscopy and HR-MALDI/MS, and identified as alpha-D-galactopyranosyl-(1 -> 6)-alpha-D-galactopyranosyl-(1 -> 6)-alpha-D-glucopyranosyle-(1 -> 2)-beta-D-fructofuranosyle citric acid. The isolated oligosaccharide citric acid derivative revealed promising anti-influenza A virus with 50% inhibition concentration (IC50) of 0.162 nM/mL and 50% cytotoxic dose (CC50) of >2.38 nM/mL.