Abstract
The bioassay of 5-fluorouracil is an useful technique to obtain pharmacokinetic data in order to establish reasonable administration schedules of this particular drug. However, the growth-inhibition circle which is produced by this agent on the agar plate in this method has not been proved to be invited by whether solely original agent itself or together with some active metabolite of the drug.
We studied on this subject, employing an unique technique, the combination of paper-chromatography and bioassay, using the tissue homogenate from S-D rats. The following results were obtained:
1. Three biologically active substances which were designated “A”, “B” and “C” respectively contributed to produce bacterial growth inhibition circle on the agar plate.
2. These three substances were proved to be originated from administered 5-fluorouracil.
3. These substances were purified and were chemically identified that “A” is 5-fluorouracil, “B” is 5-fluorouridine, “C” is 5-fluorouridylic acid and 5-fluorouridine dishosphate.
