Lignan glycosides and flavonoids from Saraca asoca with antioxidant activity

Five lignan glycosides, lyoniside, nudiposide, 5-methoxy-9-beta-xylopyranosyl-(-)-isolariciresinol, icariside E-3, and schizandriside, and three flavonoids, (-)-epicatechin, epiafzelechin-( 4 beta -> 8)-epicatechin and procyanidin B-2, together with beta-sitosterol glucoside, were isolated from a methyl alcohol ( MeOH) extract of Saraca asoca dried bark. Their structures were determined by 1D and 2D nuclear magnetic resonance ( NMR) and mass spectroscopic analysis. Antioxidant activities were evaluated by 1,1-diphenyl-2-picrylhydrazyl ( DPPH) radical-scavenging assay.