Lignans and sesquiterpenoids from the stems of Schisandra bicolor var. tuberculata

A pair of new tetrahydrofuran lignan enantiomers, (±)-schibiculatin A [(±)- 1 ], a new enedione lignan, schibiculatin B ( 2 ), two new cadinane-type sesquiterpenoids, schibiculatins C ( 3 ) and D ( 4 ), along with two known seco -cadinane-type sesquiterpenoids ( 5 and 6 ) and seven known miscellaneous lignans ( 7 – 13 ) were isolated from the stems of Schisandra bicolor var. tuberculata . The structures of 1 – 4 were elucidated by comprehensive analysis of their spectroscopic data, quantum chemical calculations, as well as single-crystal X-ray diffraction. A few isolated compounds were tested for their protective activities against corticosterone-induced apoptosis in PC12 cells. Among them, compounds 5 and 6 showed moderate activities. Graphical Abstract