Structure of formamidopyrimidine adducts as determined by NMR using specifically 15N-labeled guanosine

Chemical carcinogens are generally electrophilic species that interact with nucleophilic sites on cellular DNA (1). The specific site of interaction is governed by several factors, two of the most important being carcinogen reactivity and the reactivity of the site in question. Of the many nucleophilic sites on DNA the one that is most nucleophilic and thus generally most reactive is the N 7 -position of guanine