Antioxidant activities of new flavonoids from Cudrania tricuspidata root bark.

Two new flavonoids, hydroxybenzyl flavonoid glycosides (6-p-hydroxybenzyl kaempferol-7-O-beta-D-glucopyranoside named cudranian 1 and 6-p-hydroxybenzyl quercetin-7-O-beta-D-glucopyranoside named cudranian 2), and 3 known flavonoids (kaempferol-7-O-beta-D-glucopyranoside, quercetin-7-O-beta-D-glucopyranoside and aromadendrin) were isolated from root bark of Cudrania tricuspidata and their structures were elucidated by spectroscopic methods. These compounds showed remarkable radical scavenging effects against 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and anti-lipid peroxidation efficacy on human low-density lipoprotein by TBARS assay.