A new flavonoid glycoside from the root bark of Morus alba L

A new guibourtinidol glycoside, (2R,3S)-guibourtinidol-3-O-α-d-apiofuranosyl-(1 → 6)-O-β-D-glucopyranoside (1), and three known compounds, quercetin 7-O-β-D-glucopyranoside (2), syringaresinol-4-O-β-D-glucopyranoside (3) and dehydrodiconiferyl alcohol 4,9'-di-O-β-D-glucopyranoside (4), were isolated from the root bark of Morus alba L. through repeated silica gel, octadecyl silica gel and Sephadex LH-20 column chromatography for the n-BuOH fraction. The chemical structure of the compounds was elucidated based on MS, infrared, 1D and 2D NMR spectroscopic data. Compounds 2-4 were also isolated for the first time from the root bark of M. alba L. in this study.