Oxidative and hydrolytic DNA cleavage by Cu(II) complexes of salicylidene tyrosine schiff base and 1,10 phenanthroline/bipyridine

Abstract

Ternary Cu(II) complexes [Cu(II)(saltyr)(B)] ( 1, 2), (saltyr = salicylidene tyrosine, B = 1,10 phenanthroline ( 1) or 2,2′ bipyridine ( 2)) were synthesized and characterized by various techniques. The complexes exhibit square pyramidal (CuN 3O 2) geometry. CT-DNA binding studies revealed that the complexes show good binding propensity ( K b = 3.47 × 10 4 M −1 and 3.01 × 10 4 M −1 for 1 and 2, respectively). The role of these complexes in the oxidative and hydrolytic DNA cleavage was studied. The catalytic ability of 1 and 2 follows the order: 1 > 2. The rate constants for the hydrolysis of phosphodiester bond were determined as 2.80 h −1 and 2.11 h −1 for 1 and 2, respectively. It amounts to (0.58–0.77) × 10 8 fold rate enhancement compared to non-catalyzed DNA cleavage, which is significant.