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%‐Et OH 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 ‐ β ‐ d ‐glucopyranoside ( 1 ), 1,2,13,14‐tetramethoxydibenzocyclooctadiene 3,12‐ O ‐ β ‐ d ‐diglucopyranoside ( 2 ), 3,7‐dihydroxy‐1,2,13,14‐tetramethoxydibenzocyclooctadiene 12‐ O ‐ β ‐ d ‐glucopyranoside ( 3 ), thymoquinol 2‐ O ‐ β ‐ d ‐apiofuranosyl‐(1→6)‐ β ‐ d ‐glucopyranoside ( 4 ), thymoquinol 2‐ O ‐ α ‐ d ‐arabinofuranosyl‐(1→6)‐ β ‐ d ‐glucopyranoside ( 5 ), thymoquinol 5‐ O ‐ β ‐ d ‐apiofuranosyl‐(1→6)‐ β ‐ d ‐glucopyranoside ( 6 ), and thymoquinol 5‐ O ‐ α ‐ d ‐arabinofuranosyl‐(1→6)‐ β ‐ d ‐glucopyranoside ( 7 ). The neuroprotective activity of 1 – 7 was evaluated on PC 12 cells with neurotoxicity induced by amyloid‐beta 1 – 42 (A β 1 – 42 ). Compounds 2 and 3 showed protecting activity against A β ‐induced toxicity in PC 12 cells.