Antidepressant Abietane Diterpenoids from Chinese Eaglewood

Ten new abietane diterpenoids, aquilarabietic acids A–J (1–10), and a new podocarpane diterpenoid, aquilarabietic acid K (11), were isolated from the petroleum ether and ethanol extracts of Chinese eaglewood. Among them, 3, 9, and 10 are artifacts. Their structures were established on the basis of data from extensive spectroscopic and X-ray diffraction analyses. Bioassay results indicated that 1 at 10 μM demonstrated remarkable antidepressant activity in vitro by inhibiting norepinephrine reuptake in rat brain synaptosomes by 81.4% and with an IC50 value of 9.1 × 10–7 M.