Purine riboside-5'-O-triphosphate (sodium salt)

Purine riboside-5'-O-triphosphate (PRTP) is an active metabolite of the antiviral, antibacterial, and anticancer agent nebularine .¹ It is formed from nebularine by adenosine kinase, which results in depletion of intracellular ATP levels and induces cell death in isolated rat tmocytes, an effect that can be reduced by the adenosine kinase inhibitor 5-iodotubercidin . PRTP is an inhibitor of DNA primase ATP and GTP polymerization activities (IC₅₀s = 35 and 28 µM, respectively, for the human enzyme) and of calmodulin-dependent protein kinase II (CaMKII; K_i = 590 µM).^2,3