Two new diterpenoids from the buds of Wikstroemia chamaedaphne.

Two new diterpenoids, wikstroelide Q (1) and prostratin Q (5), together with three known diterpenoids, pimelea factors P₂ (2), P₃ (3), and prostratin (4), and five known lignans, (+)-epipioresinol (6), (+)-isolariciresinol (7), (−)-lariciresinol (8), (+)-epi-sesaminone (9), and prestegane B (10), were isolated from the buds of Wikstroemia chamaedaphne Meissn. Their structures were elucidated by a combination of spectroscopic analyses. Compounds 1–10 were evaluated for their cytotoxicities against HL-60, SMMC-7721, A549, MCF-7, SW480, and BEAS-2B cell lines in vitro.