N-salicylidene- L -glutamatocopper(II) complexes and their antimicrobial effects

Abstract

Reaction of an ethanolic solution of N-salicylidene- l -glutamatodiaquacopper(II) monohydrate with pyridine, 2-methylpyridine, 4-methylpyridine, 2-aminopyridine, 2,6-diaminopyridine, quinoline, 2-methylquinoline, 4-methylquinoline or 3-methylisoquinoline resulted in solid products containing complexes of the type Cu(sal- l -glu)L with distorted square-pyramidal coordination geometry. The products were characterized by elemental analysis, electronic spectroscopy and magnetic susceptibility measurements. Antimicrobial effects were tested on various strains of bacteria, yeasts and filamentous fungi. To compare the influence of individual ligands (neutral as well as anionic) on their biological activity, copper(II) complexes containing water and a Schiff base derived from salicyldehyde and methyl- and ethyl-esters of l -glutamic acid [Cu(sal-5-Me- l -glu)(H2O)2 and Cu(sal-5-Et-l-glu)(H2O)2] were also prepared and studied. Bioactivities of complexes tested were found to decrease in the sequence bacteria > filamentous fungi > yeasts.