Two new neolignan glucosides from Arctii Fructus

Two new neolignan glucosides named (7S, 8R)-4,7,9,9′-tetrahydroxy-3,3′-dimethoxyl-7′-oxo-8-4′-oxyneolignan-4-O-β-d-glucopyranoside (1) and (7′S, 8′R, 8S)-4,4′,9′-trihydroxy-3,3′-dimethoxy-7′,9-epoxylignan-7-oxo-4-O-β-d-glucopyranosyl-4′-O-β-d-glucopyranoside (2), together with two small molecular peptides named 3-benzyl-6-(1-hydroxyethyl)-2,5-piperazinedione (3) and 3-benzyl-2,5-piperazinedione (4), were isolated from the extract of Arctii Fructus. Their structures and absolute configurations were elucidated by various spectroscopic methods (IR, HR-ESI-MS, 1D and 2D NMR, and CD).