Anti-proliferative diterpenes from Dacrycarpus imbricatus.

A new diterpene, cassipouryl hexadecanoate (2), in addition to the cassipourol (1) and four terpenes (3-6) were isolated from the twigs and leaves of Dacrycarpus imbricatus (Blume) de Laub. The structures of the two monocyclic diterpenes (1, 2), were elucidated on the basic of 1D and 2D NMR spectroscopic data and compared with the literature. These two monocyclic diterpenes (1, 2) were tested for their anti-proliferative activity on acute myeloid leukemia (OCI-AML) cells. The results showed that 1 had significantly anti-proliferative activity whereas 2 was weakly active.

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.

20-Hydroxyecdysone from Dacrycarpus imbricatus bark inhibits the proliferation of acute myeloid leukemia cells.

OBJECTIVE: To investigate the anti-proliferative effects of 20-hydroxyecdysone isolated from the bark of Dacrycarpus imbricatus (Blume) de Laub. METHODS: Column chromatography was used for isolation of compounds from plant material. The structure of the isolated compound was identified by mass spectrometry and nuclear magnetic resonance techniques, including HSQC, HMBC, NOE-difference experiments. The isolated compound was tested for its anti-proliferative activity in acute myeloid leukemia (AML) and OCI-AML cells. RESULTS: Compound 1 was isolated from the ethyl acetate fraction of Dacrycarpus imbricatus barks by column chromatography. Its chemical structure was identified as 20-hydroxyecdysone (20HE), a cholestane-type ecdysteroid, by a combination of mass spectrometry and nuclear magnetic resonance spectrometric analyses. Our goal was to test the anti-proliferative activity of 20HE using the OCI-AML cell line. 20HE significantly decreased OCI cell number at a concentration of 1 mg/mL, whereas lower concentrations were ineffective. Moreover, this decrease was due to partial blockage of the G1/S phase of the cell cycle, with a reduction of cells in the G2M phase, not due to increased apoptosis. CONCLUSIONS: This indicates that 20HE significantly decreases the number of cells in the G1/S phase of the cell cycle in human AML cells. This is the first time that the anti-proliferative activity of 20HE against a human tumor cell line has been reported.