Bioassay-guided Isolation of Antitumor Compounds from Derris trifoliate Lour and Their Interaction with DNA

Two antitumor compounds,tephrosin(1) and rotenone(2),were acquied by bioassay-guided isolation from Derris trifoliate Lour.Compounds 1 and 2,assayed by SRB(Sulforhodamine B) methods,showed antitumor activities against cell lines of HCT8,BEL7402,BGC823,A549 and A2780 in vitro with IC50 values from 0.1 to 90.0 μmol/L.The interaction of the compounds with HS-DNA was investigated using UV spectra and fluorescent spectra.The absorbance values at the UV max peaks of compounds 1 and 2 were reduced by adding HS-DNA while the intensity of fluorescent spectra of EB-HS-DNA were gradually weaken following the increased amounts of compounds 1 and 2.It indicated that the mode of antitumor activities of compounds 1 and 2 was relative to binding with DNA through intercalation mode.