Triterpenoids from Abies faxoniana and their cytotoxic activities

Two previously unreported triterpenoids (1 and 2) and four known compounds were isolated from Abies faxoniana. Compound 1 has a α,β-unsaturated-γ-lactone ring conjugated with the C-22/23 olefin in the C-17 side chain. The structures of the new compounds were established on the basis of spectroscopic data analysis. These compounds were tested for their cytotoxicities against six human tumour cell lines. Compound 1 showed cytotoxic activities against MCF-7 and A549 cells with IC₅₀ values of 7.5 and 8.7 μM, respectively.