View article

The coordination modes of copper(II) complexes of Schiff base-derived coumarin ligands, which had previously shown good anti-Candida activity, were investigated by pH-potentiometric and UV-Vis spectroscopic methods. These studies confirmed the coordination mode of the ligands to be through the N of the imine and deprotonated phenol of the coumarin-derived ligand in solution. In addition, the more active complexes and their corresponding ligands were investigated in the presence of copper(II) in liquid and frozen solution by ESR spectroscopic methods. A series of secondary amine derivatives of the Schiff base ligands, were isolated with good solubility characteristics but showed little anti-Candida activity. However, cytotoxicity studies of the secondary amines, together with the copper complexes and their corresponding ligands, against human colon cancer and human breast cancer cells identified the …