Figure 2:

³¹P-NMR spectra for the reaction of MnCTP and phosphoramidate (5). (A) ³¹P-NMR spectrum for the reaction mixture containing 2.5 mM CTP, 5.0 mM phosphoramidate and 5.0 mM MnCl₂ in 100 mM HEPES/K⁺, 100 mM KCl , at pH 8.0 for 8 h at 30 °C. The pH was adjusted to 12 to oxidize the manganese, centrifuged and then 10 mM EDTA was added. (B) Same reaction conditions as in (A), except 15 μM Cj1416 was added. (C) Control sample of authentic cytidine diphosphoramidate (3).