Schisarisanlactones A and B: A new class of nortriterpenoids from the fruits of Schisandra arisanensis

► Two novel nortriterpenoids 1 and 2 were isolated from the fruits of Schisandra arisanensis. ► Compounds 1 and 2 possess an unprecedented 5/5/7/5/5-fused pentacyclic ring system. ► Biogenetic pathway for compounds 1 and 2 is unique and has been proposed in this article. ► Schisarisanlactone A (1) showed significant anti-HIV activity.