New Thymoquinol Glycosides and Neuroprotective Dibenzocyclooctane Lignans from the Rattan Stems of Schisandra chinensis

Three new lignans (1-3), together with four new thymoquinol glycosides (4-7), were isolated from 70%-EtOH extract of the rattan stems of Schisandra chinensis. The structures of 1-7 were elucidated by detailed spectroscopic analyses, and these new compounds were identified as pinobatol-9-O-beta-D-glucopyranoside (1), 1,2,13,14-tetramethoxydibenzocyclooctadiene 3,12-O-beta-D-diglucopyranoside (2), 3,7-dihydroxy-1,2,13,14-tetramethoxydibenzocyclooctadiene 12-O-beta-D-glucopyranoside (3), thymoquinol 2-O-beta-D-apiofuranosyl-(1 -> 6)-beta-D-glucopyranoside (4), thymoquinol 2-O-alpha-D-arabinofuranosyl-(1 -> 6)-beta-D-glucopyranoside (5), thymoquinol 5-O-beta-D-apiofuranosyl-(1 -> 6)-beta-D-glucopyranoside (6), and thymoquinol 5-O-alpha-Darabinofuranosyl-(1 -> 6)-beta-D-glucopyranoside (7). The neuroprotective activity of 1-7 was evaluated on PC12 cells with neurotoxicity induced by amyloid-beta 1-42 (A beta(1-42)). Compounds 2 and 3 showed protecting activity against A beta-induced toxicity in PC12 cells.