Triterpenes from Tripterygium wilfordii Hook

Two new friedelane-type triterpenes, tripterfrielanons A (1) and B (2), along with six known triterpenoids, friedelin (3), canophyllal (4), canophyllalic acid (5), 3-oxo-29-hydroxyfriedelane (6), wilforlide A (7), wilforlide B (8), have been isolated from the EtOH extract of the roots of Tripterygiumwilfordii Hook.f. Compounds 4, 5, 6 were isolated for the first time from this plant. The new triterpenes 1 and 2 exhibited mild cytotoxic activity against human Hela cell lines in vitro. The assay showed the IC50 of 1 and 2 were 8.5 and 25 microg/mL, respectively.