Synthesis, IR characterization and antioxidant capacity of Cu(II) complexes with amino acids and melatonin

Abstract

Reactions between anhydrous copper(II) chloride in methanol and five compounds (alanine, glycine, histidine, L-tryptophan, and melatonin) were examined. The resulting products were characterized by FTIR spectroscopy. Cu(II) complexes with glycine and alanine showed more complex structures than standard bis(glycinato)- and bis(alaninato)copper(II) complexes. Antioxidant capacity of the synthesized complexes ranged from 121.6 to 734.4 µM, with the copper-alanine combination showing the strongest activity. A high antioxidant capacity of the copper complex with melatonin (673.8 µM) was also observed.