Four new neolignan glucosides from the fruits of Arctium lappa.

Four new neolignan glucosides named (7S, 8R)-4,7,9,9'-tetrahydroxy-3,3'-dimethoxy-8-O-4'-neolignan-9'-O-β-d-apiofuranosyl-(1 → 6)-O-β-d-glucopyranoside (1), (8R)-4,9,9'-trihydroxy-3,3'-dimethoxy-7-oxo-8-O-4'-neolignan-4-O-β-d-glucopyranoside (2), (7R, 8S)-dihydrodehydrodiconiferyl alcohol-7'-oxo-4-O-β-d-glucopyranoside (3), and (7'S, 8'R, 8S)-4,4',9'-trihydroxy-3,3'-dimethoxy-7',9-epoxylignan-7-oxo-4-O-β-d-glucopyranoside (4) were isolated from the fruits of Arctium lappa L. Their structures and absolute configurations were elucidated on the basis of comprehensive spectroscopic analyses (UV, IR, HR-ESI-MS, 1D and 2D NMR, CD), as well as by comparison with known analogues in the literature.