Chemical constituents from the leaves of Pinus dalatensis Ferré

A phytochemical study of n-hexane and ethyl acetate extracts of Pinus dalatensis Ferré leaves led to the isolation of 11 compounds, including one caryolane sesquiterpenoid (1), five labdane diterpenoids (2, 3, 4, 5, 6), one serratane triterpenoid (7), one diacylated flavonoid glucoside (8), one stilbenoid (9) and two sterols (10, 11). The structural characterisation of the isolated compounds was elucidated by spectroscopic data and comparison with the literature report on the chemical constituents from Pinus dalatensis Ferré. Futhermore, three compounds 1, 4 and 6 were obtained for the first time from the genus Pinus. Besides, compounds (2, 3, 5, 8, 9) were also subjected to cytotoxicity effect on SK-LU-1, MCF-7 and Hep-G2 cell lines, but only compound 9 expressed activities with IC₅₀ values of 141.22, 127.81 and 166.84 μM, respectively.