Two novel zinc complexes of disubstituted 2,2′-bipyridine with ammonium groups as artificial nucleases

Two novel zinc complexes of disubstituted 2,2′-bipyridine with ammonium groups, [Zn(L1)3](ClO4)8·3H2O (1) and [Zn(L2)3](ClO4)8 (2) (L1 = [4,4′-(Me2NHCH2)2-bpy]2+, L2 = [5,5′-(Me2NHCH2)2-bpy]2+, bpy = 2,2′-bipyridiyl) were synthesized as artificial nucleases. The outside electrostatic binding interaction between these complexes and calf thymus DNA was confirmed by UV and CD spectroscopies. Even at low concentration (2.0 × 10−4 M), both complexes can effectively cleave supercoiled plasmid DNA to nicked form, giving hydrolysis rate constants of 1.84 × 10−5 and 2.16 × 10−5 s−1, respectively.