Minor dibenzocyclooctadiene lignans with antifibrotic potential from the fruits of Schisandra chinensis.

An intensive phytochemical investigation of the fruits of Schisandra chinensis has led to the isolation and identification of ten formerly undescribed minor dibenzocyclooctadiene lignans designated as schisanchignans A-J. Notably, schisanchignan A represents a rare dearomatized lignan featuring a dienone fragment and a novel 6,10-epoxy ring, while schisanchignans G-I are first examples within this class of lignans to incorporate two extra small-molecule substructures. The absolute configurations of the core structures in these compounds were established by analyses of electronic circular dichroism data. In addition, the inhibition of these lignans against nitric oxide production in RAW264.7 macrophages and against two fibrotic marker proteins in HK-2 cells was also evaluated, and selective compounds exerted promising antifibrotic potential.