Two new rhamnopyranosides of neolignans from Sanguisorba officinalis

Two new rhamnopyranosides of neolignans, (7S,8R)-4,9,5',9'-tetrahydroxy-3,3'-dimethoxy-8-O-4'-neolignan-7-O-α-l-rhamnopyranoside (1) and (7S,8R)-4,9,9'-trihydroxy-3,3',5'-trimethoxy-8-O-4'-neolignan-7-O-α-l-rhamnopyranoside (2), together with a known compound (7S,8R)-4,7,9,9'-tetrahydroxy-3,3'-dimethoxy-8-O-4'-neolignan (3), were isolated from the 80% EtOH extract of the roots of Sanguisorba officinalis. Their structures were characterized by spectroscopic analysis including 1D NMR, 2D NMR, and HR-ESI-MS, and chemical method.