Tetrahydrouridine

Tetrahydrouridine (CAS No.: 18771-50-1) is a nucleoside analog and a potent competitive inhibitor of cytidine deaminase (CDA), an enzyme responsible for the deamination of cytidine to uridine in pyrimidine metabolism. By binding to the active site of CDA with greater affinity than endogenous cytidine, tetrahydrouridine effectively blocks cytidine deamination, thereby preserving intracellular cytidine levels and modulating nucleoside metabolism. This inhibitory activity has been characterized in vitro with high potency in the nanomolar range against both human and bacterial CDA enzymes. Through suppression of CDA-mediated catabolism, tetrahydrouridine is widely employed in biochemical and pharmacological studies to investigate cytidine metabolic pathways, enzyme regulation, and nucleoside turnover. It is also extensively utilized in drug discovery and preclinical research to enhance the stability and efficacy of cytidine analog-based therapeutics, such as decitabine, by reducing their metabolic degradation; in vivo studies have demonstrated that co-administration can potentiate antitumor activity in relevant animal models. The compound is therefore a valuable tool in cell-based assays and animal studies focused on epigenetic modulation, cancer biology, and nucleoside analog optimization, with experimental concentrations or dosing regimens typically tailored to specific study designs and research objectives.