Aerobic Oxidation of in Situ Generated Cyanine Dyes Leading to DNA Damage

DNA damage induced by noncatalytic aerobic oxidation of pyridinocyanine dyes is described. The dyes are generated in situ during spontaneous oxidations of tetrakis- and bis­(N-methylpyridin-4-ium)­alkane salts. The mechanism of aerobic oxidation of the latter compound is proposed, and a rare direct catalyst-free transition from saturated alkane to a gem-diol is demonstrated. Thermal DNA oxidation by cyanine dyes has potential in ROS-based cancer treatment and biomedical research.