Aminyl and iminyl radicals from arylhydrazones in the photo-induced DNA cleavage Original Research Article

Photolytic cleavage of the nitrogen–nitrogen single bond in benzaldehyde phenylhydrazones produced aminyl (R2Nradical dot) and iminyl (R2CNradical dot) radicals. This photochemical property was utilized in the development of hydrazones as photo-induced DNA-cleaving agents. Irradiation with 350 nm UV light of arylhydrazones bearing substituents of various types in a phosphate buffer solution containing the supercoiled circular φX174 RFI DNA at pH 6.0 resulted in single-strand cleavage of DNA. Attachment of the electron-donating OMe group to arylhydrazones increased their DNA-cleaving activity. Results from systematic studies indicate that both the aminyl and the iminyl radicals possessed DNA-cleaving ability.