Site-specific labelling of caged ATP with deuterium or 18oxygen

[3-D]-2-Nitroacetophenone and [alcohol- 18 O]-1-(2-nitrophenyl)ethyl alcohol were prepared and used to synthesise labelled P 3 -1-(2-nitrophenyl)ethyl esters of ATP (caged ATP) with isotope present either as deuterium on the 3-position of the nitrosubstituted ring or as 18 oxygen in the bridging position between the terminal phosphate and the nitrophenylethyl group. The availability of the deuterated compounds enabled complete assignment of their 1 H NMR spectra