TABLE 1

Steady-state kinetic constants for formation of 5′-DFCR from capecitabine

Capecitabine (0-10 mM) was incubated with purified recombinant carboxylesterases in 20 mM HEPES buffer, pH 7.4, containing 10% ethylene glycol at 37°C for 5 to 30 min in 125 μl of reaction volume. The product, 5′-DFCR, was quantitated using a Shimadzu LC-MS 2010. The concentration of 5′-DFCR was determined from a standard curve generated under identical conditions with each experiment. Values are presented as mean ± S.E. from at least three independent experiments.