Schisandrin B (Sch B), a dibenzocyclooctadiene derivative isolated from the fruit of Schisandra chinensis, has been shown to enhance mitochondrial antioxidant status in liver, heart and brain tissues in rodents. It is the most abundant and biologically active dibenzocyclooctadiene lignan present in Fructus Schisandrae. While Sch B has been isolated from Fructus Schisandrae in the laboratory, the experimental procedure was usually lengthy and the yield was relatively low. And it is a highly desirable ingredient for a dietary supplement. Schisandrin B is more potent than its enantiomer in enhancing cellular glutathione and heat shock protein production as well as protecting against oxidant injury in H9c2 cardiomyocytes.