Electrochemical behaviour and DNA intercalation studies of novel antimicrobial Bis - Cu(II) substituted Dipyridophenazine complexes

The public health threat caused by antimicrobial drug resistance has led to research towards alternatives to current chemotherapeutics, with metal-based complexes providing an excellent and promising avenue. Cu(II) species are of particular interest in this area due to their redox properties that could interfere with and inhibit bacterial growth. Here, we report the synthesis and characterisation of four novel bis-Cu(II) substituted Dipyridophenazine complexes. The dypyridophenazine ligands (DPPZ) where synthesized with different substituents at the 11 position (i.e. NO₂, Br, CH₃ and CN) to evaluate the effect of the functionality with respect the redox and biological behaviour. The DNA intercalation properties together with a detailed electrochemical study of the complexes and of the ligands is reported. The toxicity of the complexes against Methicillin Resistant Staphylococcus aureus (MRSA) and the yeast Candida albicans was characterised and the promise of this family of complexes as novel anti-microbial drugs in a post-antibiotic age was demonstrated.