Diterpenoids from the branch and leaf of Abies fargesii

Five new abietane diterpenoids, named abifadines A-E (1-5), and nine known ones (6-14), together with two known podocarpenes (15 and 16), were isolated from the branch and leaf of Abies fargesii. Their structures including the relative configurations were established on the basis of extensive spectroscopic analyses. The absolute configuration of 1 was determined through single-crystal X-ray diffraction analysis with Cu Kα irradiation. All the isolates were evaluated for their in vitro cytotoxicities. Only compounds 5 and 12 exhibited weak anti-proliferative effects against three cancer cell lines (B16, MCF7, and HepG2) with IC50 values range from 14.8 to 42.8 μM. The antimicrobial activities against Staphylococcus aureus, Escherichia coli and Monilia albicans of all compounds were also tested, but none of them showed significant activities.