A novel aminoketooxime ligand and its mononuclear Cu(II) and Mn(II) complexes were synthesized. The structures of the synthesized compounds were illuminated by elemental analysis, inductively coupled plasma optical emission spectrometry, the Fourier transform infrared, H-1- and C-13-NMR, UV-Vis, magnetic susceptibility and conductivity measurements. According to the characterization studies ligand to metal ratio was found to be 2: 1 with strong binding affinity of the ligand to the metal ions. In addition, complexes have been tested for their catecholase and phenoxazinone synthase-like activities. Kinetic studies were also carried out yielding V-max, k(cat) and KM values of both complexes for catecholase and phenoxazinone synthase-like activities. Both complexes efficiently catalyzed the reactions of the enzymes they mimicked.