Aromatic chemical constituents of Choerospondias axillaries and their in vitro antitumor activity

Aim To explore the antitumor constituents of Choerospondias axillaries Burtt.et Hill.Methods The separation procedure was guided by flow cytometric bioassay using tsFT210 cells to obtain antitumor active fractions.Various column chromatography and preparative TLC were used to obtain pure compounds from the active fractions.Structures of the compounds obtained were investigated by modern spectroscopic methods.Flow cytometry and SRB method were employed to evaluate antitumor activity of the compounds.Results Compounds 1～5 were isolated from the barks of Choerospondias axillaries and they were identified as pinocembrin(1),naringenin(2),chrysin(3),dibutyl phthalate(4)and tetradecyl E-ferulate(5)respectively. In SRB assay,1～5 at 10 μmol·L -1 inhibited the proliferation of human cancer HCT-15 and HeLa cells with the inhibition rates of 21.5%(1),37.3%(2),33.1%(3),20.1%(4)and 17.0%(5)for HCT-15 and 30.0%(1),22.1%(2),22.4%(3),30.4%(4)and 26.4%(5)for HeLa cells,respectively.Their IC_ 50 values were 83 μmol·L -1(1),76 μmol·L -1(2)and more than 100 μmol·L -1(3～5)on HCT-15,and 84 μmol·L -1(1)and more than 100 μmol·L -1(2～5)on HeLa cells,respectively.Flow cytometric analysis indicated that 1 and 2 slightly inhibited the cell cycle of tsFT210 cells at the G_2/M phase at higher concentration while 4 showed strong cytotoxicity at higher concentration but at lower concentration inhibited the cell cycle at the G_0/G_1 phase.Conclusion Compounds 1 and 3～5 are isolated from Choerospondias axilla-ries for the first time,and compounds 1～5 are the first report as the antitumor constituents of Choerospondias axillaries.