Cu(II) complexes of flavonoids in solution: Impact of the Cu(II) ion on the antioxidant and DNA-intercalating properties

•Complexes of Cu(II) with flavonoids are studied in two solvents: DMSO and methanol.•Formation of complexes is monitored by UV-Vis spectroscopy and DFT calculations.•Kaempferol, luteolin and fisetin complexes show enhanced radical scavenging effect.•Molecular docking study indicates the interaction with DNA via intercalation.•Complexes may represent perspective therapeutics for neurodegenerative disorders.