Three new lignan glucosides from the roots of Scutellaria baicalensis

Three new lignan glucosides, baicalensinosides A–C (1–3), were isolated from the roots of Scutellaria baicalensis. The structural elucidation was achieved by in-depth spectroscopic examinations and qualitative chemical test. Structurally, these compounds belong to the 3,4-dibenzyltetrahydrofuran-type lignan glycoside with a mono-hydroxyl substitution at the 7′-position of benzylidene group on the numbering system of lignans being one of their shared critical features. The anti-osteoporotic activity of the isolated compounds was assessed in an in vitro osteoprotegerin (OPG) transcriptional activity assay using dual luciferase reporter detection. At 10 μmol/L, compounds 1–3 increased the relative activating ratio of OPG transcription to 1.83, 0.84 and 0.98 times that of the control group, respectively.