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 mu mol/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.