New Labdane-Type Diterpenoids fromAmentotaxus argotaenia

A new labdane diterpene, amentotaxin A (1), and an unprecedented dinorlabdane diterpene, amentotaxin B (2), were isolated from the stems of Amentotaxus argotaenia (Hance) PILGER, together with seven known compounds. Their structures were identified by in-depth spectroscopic and mass-spectrometric analyses.