Photoinduced DNA cleavage by naphthalimide hydroperoxide-specific strand scission at -GG- site of DNA

We have prepared a series of naphthalene hydroperoxides (1-3) which possess hydroperoxy group at gamma-position of imide carbonyl. Upon photoirradiation (greater than 350 nm) hydroperoxides (1-3) decomposed with efficient generation of hydroxyl radical, which was confirmed by esr spin trapping technique using dimethylpyrroline oxide as a spin trapper. All these hydroperoxides induced DNA strand scission upon photoirradiation (greater than 350 nm), especially hydroperoxide 3 cleaved plasmid phi X 174 DNA (Form I) to give nicked (Form II) and linear (Form III) DNA even at 1 microM concentration. Further, it was observed that 3 exclusively cleaved DNA at the 5'-G site of -GG-sequence.