Rapid photolytic release of cytidine 5′-diphosphate from a coumarin derivative: a new tool for the investigation of ribonucleotide reductases Original Research Article

In order to study the long-range radical transfer in the Escherichia coli ribonucleotide reductase (RNR), caged cytidine 5′-diphosphate (CDP) 1 was synthesized, which contains the photolabile (7-diethylaminocoumarin-4-yl)methyl moiety. The caged CDP 1 triggers the release of CDP when irradiated at wavelengths between 365 and 436 nm. The rate constant of the formation of alcohol 2 and cytidine 5′-diphosphate 3 is 2×108 s−1 and the quantum efficiency for the disappearance of caged CDP 1 is 2.9%.