Synthesis and analysis of the anticancer activity of platinum(ii) complexes incorporating dipyridoquinoxaline variantsElectronic supplementary information (ESI) available: Further synthesis and characterisation data including detailed spectra. CCDC 1008700 for [Pt(dpq)(SS-dach)](ClO4)2·1.75H2O. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4dt02133a

• Main Authors: Pages, Benjamin J, Li, Feng, Wormell, Paul, Ang, Dale L, Clegg, Jack K, Kepert, Cameron J, Spare, Lawson K, Danchaiwijit, Supawich, Aldrich-Wright, Janice R
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c4dt02133a

Eight platinum( ii ) complexes with anticancer potential have been synthesised and characterised. These complexes are of the type [Pt(I L )(A L )] 2+ , where I L is either dipyrido[3,2- f :2′,3′- h ]quinoxaline (dpq) or 2,3-dimethyl-dpq (23Me 2 dpq) and A L is one of the R , R or S , S isomers of either 1,2-diaminocyclohexane ( SS -dach or RR -dach) or 1,2-diaminocyclopentane ( SS -dacp or RR -dacp). The CT-DNA binding of these complexes and a series of other complexes were assessed using fluorescent intercalator displacement assays, resulting in unexpected trends in DNA binding affinity. The cytotoxicity of the eight synthesised compounds was determined in the L1210 cell line; the most cytotoxic of these were [Pt(dpq)( SS -dach)]Cl 2 and [Pt(dpq)( RR -dach)]Cl 2 , with IC 50 values of 0.19 and 0.80 μM, respectively. The X-ray crystal structure of the complex [Pt(dpq)( SS -dach)](ClO 4 ) 2 ·1.75H 2 O is also reported. Platinum complexes incorporating variants of dpq were synthesised. Their DNA affinity and cytotoxicity were compared to complexes containing phen variants, revealing unexpected trends in biological activity.