Six novel conjugates of 5-fluorouracil photosensitizer for the photodynamic therapy research (PDT) were designed and synthesized. Their structures were characterized by ¹H NMR, ¹³C NMR, IR and elemental analysis, 5-Fu and their octanol-water partition coefficients (lg P) were calculated by HPLC. Compounds 2a, 3a, 1b and 4b were evaluated by microculture tetrazolium assay (MTT) method for HL-60 cells and sulforhodamine B (SRB) method for BEL-7402 cells. The antitumor activities in vitro show that the compound 2a has a better inhibitory rate than 3a for both HL-60 and BEL-7402, as the octanol solubility of 2a is better than 3a. The compounds of 1b and 4b both show a moderate inhibiting effect, for the linkages of N—C is too stable to release 5-Fu.

Key words: 5-fluorouracil derivatives, photosensitizer agents, photodynamic therapy, octanol-water partition coefficients, anticarcinogenic activity