Synthesis, DNA intercalation and europium(III)-triggered DNA photocleavage by a bis-proflavine succinamide conjugate

We describe the synthesis of a bis-proflavine derivative containing a succinamide linking chain. Levels of pUC19 plasmid DNA photocleavage by this compound are significantly enhanced in the presence of Eu3+ (350 nm, 22 °C, pH 7.0). UV–visible spectrophotometric studies of the ligand with calf thymus DNA show bathochromic-shifts and hypochromicity in the major absorption bands of the bis-proflavine derivative. Viscosimetric analysis of the helical extension of sonicated calf thymus DNA agrees with a monofunctional intercalation process.