Uracil C-13

Uracil C‑13 is a stable isotope-labeled form of uracil in which the carbon at position 2 is replaced with the non-radioactive isotope carbon‑13. It is primarily used as a diagnostic agent in breath tests to assess gastrointestinal function and disorders such as dyspepsia and gastric emptying. The compound acts as a tracer; after administration, its metabolism can be monitored by measuring exhaled ^{13}CO_2, reflecting enzymatic activity related to pyrimidine catabolism. The mechanism involves reduction by dihydropyrimidine dehydrogenase followed by further metabolism and eventual release of labeled CO_2[1][5][6]. Otsuka Pharmaceutical developed the [^13C]-uracil breath test for clinical use, but development was discontinued for chemotherapy-induced damage and gastrointestinal motility disorders[5].

Other names

(213C)1H-pyrimidine-2,4-dione35803-45-3