[13C,15N2]-5-Fluorouracil

5-Fluorouracil (5-FU) is a metabolite of Capecitabine. Capecitabine is converted by carboxylesterase to 5'-Deoxy-5-fluorocytidine in the liver, then by cytidine deaminase to 5’-Deoxy-5-fluorouridine in the liver and tumor tissues, and finally, by thymidine phosphorylase to 5-Fluorouracil in tumors. Formulations containing 5-FU have been used in the treatment of colorectal, breast, gastric and pancreatic cancers.

Stable isotope labeled [¹³C,¹⁵N₂]-5-Fluorouracil is intended for use as an internal standard for the quantification of 5-Fluorouracil by LC or GC-mass spectrometry.