Diterpenoids from the twigs and leaves of Croton caudatus var. tomentosus.

One new 9,10-seco-abietane derivative, crotontomentosin A (1), four new abietane-type diterpenoids, crotontomentosins B-E (2-5), one new ent-halimane-type diterpenoid, crotontomentosin F (6), along with five known diterpenoids (7-11) and one known sesquiterpenoid (12) were obtained from the twigs and leaves of Croton caudatus Geisel. var. tomentosus Hook. The structures of the compounds were established on the basis of extensive spectroscopic data. Compounds 1-4 and 11 exhibited moderate to weak inhibitory activity against the proliferation of the Hela, Hep G2, MDA-MB-231, or A549 cell lines selectively.