In vivo formation of N7-guanine DNA adduct by safrole 2′,3′-oxide in mice

► N7-(3-benzo[1,3]dioxol-5-yl-2-hydroxypropyl)guanine (N7γ-SFO-Gua) was characterized. ► An HPLC-ESI-MS/MS method was first developed to measure N7γ-SFO-Gua. ► N7γ-SFO-Gua was detected in urine of mice treated with safrole 2′,3′-oxide (SFO). ► This is the first study to suggest the formation of N7γ-SFO-Gua in SFO-treated mice.