Tuning the DNA binding and cleavage of bpa Cu(II) complexes by ether tethers with hydroxyl and methoxy groups

Abstract Five bpa (bis(2-picolyl)amine) derivatives ( 1b , 2e , 3f , 4c , 5d ) carrying ether tethers with hydroxyl and methoxy groups, have been synthesized from pyridine aldehyde and the respective amines by reductive amination. Their Cu(II) complexes carrying additional nitrato ( 6a – b ) and perchlorato ( 7a – e ) ligands, respectively, have been characterized and subjected to DNA cleavage studies. Since the hydrolytic DNA cleavage activity of 6a is known from the literature, further experiments comprising the novel derivatives have been carried out. These reveal that derivative 7e was able to generate 10 times more linear DNA in a standard cleavage experiment than 6a . Considering the redox activity of the Cu(II) center, a possible oxidative cleavage activity of this kind of bpa complexes was also investigated.