Phenolic Compounds from Seeds of Astragalus sinicus and Its Antioxidative Activities

Abstract

Phytochemical examination of seeds of Astragalus sinicus has led to the isolation and characterization of kaempferol 3-O-β-D-apiofuranosyl-(1→ -2)-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (1), quercetin 3-O-β-D-xylopyranosyl-(1-→2)-β-D-glucopyranoside (2), ampelopsin (3), ampelopsin 3'-O-β-D-glucopyranoside (4), ampelopsin 3'-O-β-D-xylopyranoside (5), myricetin (6), myricetin 3'-O-β -D-glucopyranoside (7), myricetin 3'-O-β-D-xylopyranoside (8). Antioxidative activity of these compounds was determined by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Flavanonols(3, 4, and 5) showed potent antioxidative activity.