Chemical Constituents from the Leaves of Mahonia japonica

The chemical constituents of the leaves of Mahonia japonica were investigated by column chromatography. We isolated eight flavonoids, including quercetin (1), quercetin 3-O-β-D-glucopyranoside (2), quercetin 3-O-β-D-galactopyranoside (3), quercetin 3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (4), isorhamnetin (5), isorhamnetin 3-O-β-D-glucopyranoside (6), isorhamnetin 3-O-β-D-galactopyranoside (7), and isorhamnetin 3-O-β-D-glucopyranosl-(1→6)-β-D-glucopyranoside (8), and four phenollic carboxylic acids, in cluding caffeic acid (9),p-hydroxy-benzoic acid (10), protocatechuic acid (11), and vanillic acid (12) from the n-BuOH soluble fraction of the methanolic extract. The structures of these com pounds were established by spectroscopic and chemical analysis.