The interaction between 2-(5-fluorouracil-1-acetyl) amido-1,5-dimethyl glutarate enantiomer and DNA have been investigated via cyclic and differential pulse voltammetry, in which double-stranded DNA (ds-DNA) or G-quadruplex DNA (G4-DNA) modified Au electrode was used as the working electrode while was employed as the electroactive indicator. Our investigation indicates that: (1) As opposed to the influence of 5-fluorouracil (5-FU), (S)-5FUGlu and (R)-5FUGlu caused the peak potential of at Au/ds-DNA and Au/G4-DNA electrodes shift negatively|(2) 5-FU, (S)-5FUGlu and (R)-5FUGlu all caused the peak current of at the above modified electrodes to decrease, in which the inverse of current change exhibited a linear relationship with the inverse of reagent concentration|(3) Utilizing Langmuir equation the binding constants of 5-FU, (S)- and (R)-5FUGlu with ds-DNA are found to be 6.16×10³, 0.42×10³ and 0.58×10³ L•mol^－1, respectively, whereas the binding constants of 5-FU, (S)- and (R)-5FUGlu with G4-DNA are 0.78×10³, 2.60×10³ and 5.29×10³ L•mol^－1|and (4) the inhibition rates of (R)- and (S)-5FUGlu on tumor cell line HL-60 are, respectively, 55.8 and 2.8, 12.8 and 1.5, and 5.9 and 0.6 at the concentrations of 10^－4, 10^－6 and 10^－8 mol•L^－1, which is consistent with the observed tendency that (R)-5FUGlu and G4-DNA have a stronger binding affinity than that of (S)-5FUGlu.

Key words: G-quadruplex DNA, 5-fluorouracil-dipeptide derivatives, differential pulse voltammetry, enantiomer, anti-tumor activity