Abstract: Three diterpenoids, compound A (1), B(2) and C (3), have been isolated together with daucosterol (4) from the ethanol extract of Siegesbeckia glabrescens. Their chemical structures have been elucidated as ent-16β,17-dihydroxykauran-19-ocid (1), siegesbeckioside (2), darutoside (3),on the basis of chemical and spectral evidences. Compounds 1 and 2 are isolated for the first time from Siegesbeckia glebrescens.

Key words: Compositae