5-Substituted-2,2'-anhydrouridines, potent inhibitors of uridine phosphorylase.

5-Substituted-2,2'-anhydrouridines are a new class of competitive inhibitors of uridine phosphorylase. The most potent member of the series is 2,2'-anhydro-5-ethyluridine with an apparent Ki value of 25 nM. These compounds are selective inhibitors of uridine phosphorylase and have no effect on thymidine phosphorylase. 5-Substituted-2,2'-anhydrouridines are no substrates of either uridine phosphorylase or thymidine phosphorylase.