Potential Antitumor-Promoting Diterpenes from Callicarpa macrophylla Vahl

Three new labdane-type diterpenoids, callicapoic acids M1-M2 (1–2), callicarpol M3 (3), together with three known labdane-type diterpenoids (4–6) and six known isopimarane-type diterpenoids (7–12) were isolated from the dried whole herb of Callicarpa macrophylla Vahl. Their structures were established by extensive spectroscopic methods. Among them, compounds 1, 7, 10, and 11 showed strong inhibitory effects on EBV-EA induction (100% inhibition at 1000 mol ratio/TPA).