“…The chemistry and reactivity of nitrogen − ,,,,− and sulfur ,− mustards with nucleosides and DNA in vitro are well-studied. There are also numerous studies that examine the mustard-derived DNA adducts from treated cells in culture and animals, ,,,,,,, including white blood cells of patients on chemotherapeutic regimens that included a nitrogen mustard. , A variety of methods have been used to identify these adducts, including 32 P-postlabeling, , co-chromatography by HPLC with authentic standards, ,,,, and mass spectrometry. ,,− ,,, Recently, tandem mass spectrometry with stable isotope dilution has been employed to identify and quantitate some of these DNA adducts. ,,− Collectively, the studies indicate that these electrophiles react predominantly at the N7 atom of dG, although N3-dA modification also can be significant . The toxicity of mustard agents has been attributed to interstrand DNA cross-links.…”