Cytidine-5-triphosphate-13C9 (Cytidine triphosphate-13C9 dilithium, 5-CTP-13C9) dilithium is 13C-labeled Cytidine-5-triphosphate (HY-125818). Cytidine 5'-triphosphate (Cytidine triphosphate, 5-CTP) is a nucleoside triphosphate and serves as a building block for nucleotides and nucleic acids, lipid biosynthesis. Cytidine triphosphate synthase can catalyze the formation of cytidine 5'-triphosphate from uridine 5'-triphosphate (UTP). Cytidine 5'-triphosphate is an essential biomolecule in the de novo pyrimidine biosynthetic pathway in T. gondii.