Cyclic aristeromycin diphosphate ribose: A potent and poorly hydrolysable Ca2+-mobilising mimic of cyclic adenosine diphosphate ribose

Cyclic aristeromycin diphosphate ribose, a carbocyclic analogue of cyclic adenosine diphosphate ribose, was synthesised using a chemo-enzymatic route involving activation of aristeromycin 5'-phosphate by diphenyl phosphochloridate. The calcium-releasing properties of this novel analogue were investigated in sea urchin egg homogenates. While cyclic aristeromycin diphosphate ribose has a calcium release profile similar to that of cyclic adenosine diphosphate ribose (EC(50) values are 80 nM and 30 nM, respectively), it is degraded significantly more slowly (t(1/2) values are 170 min and 15 min, respectively) acid may, therefore, be a useful tool to investigate the activities of cyclic adenosine diphosphate ribose.