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

Abstract

Photolytic cleavage of the nitrogen-nitrogen single bond in benzaldehyde phenylhydrazones produced aminyl (R2N·) and iminyl (R2C=N·) radicals. This photochemical property was utilized in the development of hydrazones as photo-induced DNA-cleaving agents. Irradiation with 350nm UV light of arylhydrazones bearing substituents of various types in a phosphate buffer solution containing the supercoiled circular φX174 RFI DNA at pH6.0 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. © 2004 Elsevier Ltd. All rights reserved.