Phenolic constituents from the twigs of Betula schmidtii collected in Goesan, Korea

Six undescribed phenolic derivatives along with thirty two known compounds were isolated from the twigs of Betula schmidtii. The chemical structures were characterized through extensive spectroscopic analysis and chemical methods. All known compounds were first isolated in this plant. The anti-inflammatory effect of the isolates was tested by measuring nitric oxide production in lipopolysaccharide-activated BV-2 cells. Isotachioside, 4-allyl-2-hydrophenyl 1-O-beta-D-apiosyl-(1 (R) 6)-beta-D-glucopyranoside, genistein 5-O-beta-D-glucoside, and prunetinoside showed a slight potency to lower the NO production against LPS-activated microglia with IC50 values of 23.9, 25.3, 28.8, and 34.0 mu M, respectively.