Curcumin-based ionic Pt() complexes: antioxidant and antimicrobial activity

A series of novel cationic curcumin-based Pt( ii ) complexes with neutral (N^N) ligands and triflate anions as counterions, [(N^N)Pt(curc)]CF 3 SO 3 , 1-4 , were synthesised and fully characterised. The antioxidant radical scavenging activity of complexes 1-4 was measured spectrophotometrically using DPPH as the internal probe. Computational strategies have been exploited to ascertain the mechanism of antioxidant action of curcumin (H(curc)) and its Pt( ii ) complexes. Finally, compounds 1-4 were tested in vitro for their growth inhibitory activity against two bacteria ( Staphylococcus aureus and Escherichia coli ) by the disk diffusion technique at different Pt( ii ) complex solution concentrations. The effect of the complexation of H(curc) was investigated. Four new Pt( ii ) ionic complexes assembled from N-donor ligands and curcumin display interesting antioxidant and antimicrobial properties.