Mechanistic investigation of charge-remote and charge-driven fragmentation processes in 2,5-diphenyl-3,4-ethylenedioxythiophene diamidines.

Rationale: Diphenylfuran diamidines represent an important class of DNA minor groove binders of high therapeutic interest as antitumor and antibacterial agents. This study aimed to investigate fragmentation patterns in mass spectra of four diamidine derivatives with significant antitumor activity, in order to gain more insight into the structures and stability of their putative biological metabolites.

Methods: Compounds were investigated by electrospray ionization tandem mass spectrometry (ESI-MS/MS) using low-energy collision-induced dissociation (CID).