CSIRO PUBLISHING - Australian Journal of Chemistry

Dipyridophenazine Complexes of Cobalt(iii): DNA Photocleavage and Photobiology

Alison M. Funston ^A, Carleen Cullinane ^B, Kenneth P. Ghiggino ^A, W. David McFadyen ^A ^D, Stanley S. Stylli ^C and Peter A. Tregloan ^A

^A School of Chemistry, University of Melbourne, Parkville VIC 3010, Australia.
^B Peter MacCallum Cancer Institute, St Andrews Place, East Melbourne VIC 3002, Australia.
^C Department of Surgery and Department of Neurosurgery, Royal Melbourne Hospital, University of Melbourne, Parkville VIC 3052, Australia.
^D Corresponding author. Email: wdmf@unimelb.edu.au

Abstract

The UV-visible spectroscopy and photochemistry of [Co(en)₂(DPPZ)](ClO₄)₃ (DPPZ = dipyrido[3,2-a:2´,3´-c]-phenazine) in the presence of plasmid DNA and the nucleoside 2´-deoxygaunosine have been investigated. Evidence for the intercalation of the complex with DNA and photoinduced DNA strand breakage is found. The structurally related complexes [Co(en)₂(DPPN)]Cl₃ and [Co(en)₂(DPPA)]Cl₂, where DPPN = benzo[i]dipyrido[3,2-a:2´,3´-c]phenazine and DPPA = dipyrido[3,2-a:2´,3´-c] phenazine-11-carboxylic acid, have also been synthesized and characterized. In vitro cytotoxicity studies and photocytotoxicity studies of the complexes using the C6 rat glioma cell line are reported and indicate significant increases in toxicity following irradation.

Australian Journal of Chemistry 58(3) 206–212 doi:10.1071/CH04206
Submitted: 8 September 2004 Accepted: 18 January 2005 Published: 15 March 2005