Unique ions formed after reaction of LG with an equimolar mix of nucleosides. A 50/50 mixture of [12C]- and [13C3] LGE2 was incubated at 37 °C with an equimolar nucleoside mix, with LG in a 3:1 ratio per individual nucleoside. After 2 h, the reaction and individual controls (not shown), were analyzed by ESI-LC/MS in full scan, positive ion mode. (A) The ion current chromatograms for the LG-dA, LG-dG, and LG-dC adducts within the LG-nucleoside reaction are shown, along with the chromatogram for the predicted ion at m/z = 595 of an LG-dT adduct. (B) The deduced dihydroxypyrimidine structures of the LG-dA and LG-dG adducts.