Copper(II) complexes with derivatives of pyrazole as potential antioxidant enzyme mimics.

A series of six mononuclear Cu(II) complexes with pyrazole-based ligands: 5-(2-hydroxybenzoyl)-3-methyl-1-(2-pyridinyl)-1-pyrazol-4-phosphonic acid dimethyl ester (), 5-(2-hydroxyphenyl)-3-methyl-1-(2-pyridylo)-1-pyrazole-4-carboxylic acid methyl ester () and 1-benzothiazol-2-yl-5-(2-hydroxyphenyl)-3-methyl-1-pyrazole-4-carboxylic acid methyl ester () were characterized regarding to electrochemical and antioxidant properties. All complexes exhibit suitable Cu(II)/Cu(I) redox potential () to act as antioxidant enzymes mimic. The five of these complexes were found to be trifunctional enzyme mimics possessing SOD, CAT and GPx-like catalytic activities. Moreover, Cu(II) complexes were capable to decrease ROS level in melanoma cells and observed effects were not merely a reflection of cytotoxicity.