Pfaffane-type nortriterpenoids from Pfaffia pulverulenta

7-Oxopurveric acid, 7-hydroxypulveric acid and pulverulactone, three new hexacyclic nortriterpenoids, have been isolated from Pfaffia pulverulenta. The structures of the new compounds were elucidated as 3,7,11-trioxopfaffan-12-en-28-oic acid, 7a-hydroxy-3,11-dioxopfaffan-12-en-28-oic acid and 3β,12α,13β-trihydroxypfaffan-28,13-olide, respectively, by chemical transformations and extensive NMR spectral experiments.