6-Chloropurine riboside-5'-triphosphate serves as both an inhibitor and an activator in biochemical processes. It inhibits the RNA triphosphatase mRNA-capping enzyme subunit β (Cet1; IC50 = 2 µM for the GTPase activity of the S. cerevisiae enzyme), proving its efficacy against the enzyme responsible for the capping of mRNA molecules. Additionally, it acts as a phosphorylated derivative of 6-chloropurine riboside. This compound also activates the E. coli enzyme aspartate carbamoyltransferase (EC50 = 0.76 mM), demonstrating its versatility in modulating enzyme activities. It is instrumental in the synthesis of cytokinins with anticancer properties and a photoclickable form of ATP, highlighting its applications in biochemical synthesis and potential therapeutic uses.