Preparation, characterization, and biologic evaluation of copper(1I) - Schiff base complexes derived from anthranilic acid and aldoses

Abstract

Schiff bases and transition metal - Schiff base complexes are important intermediates in certain biologic processes, such as non-enzymatically controlled transamination reactions (1). In these reactions amino acids lend their amino group for Schiff base formation whereas the carbonyl group can be provided by a host of carbonyl compounds, such as pyridoxal compounds, aldoses, and certain hormones, occurring naturally in biological systems. The chemistry and the biochemistry of Schiff bases and transition metal - Schiff base complexes derived from amino acids and pyridoxal compounds, and some other carbonyl compounds that do not occur in biological systems, have been extensively studied (2, 3). Although they occur abundantly in biological systems, no attempt has been made to study the possibility of Schiff base formation in vitro utilizing the carbonyl group of aldoses. However, Horecker et al. (see refs. 4-6 in ref. 4) suggest Schiff base formation, in vivo, between an aldose and a terminal amino group associated with an amino acid of an enzyme. In the present work we prepared and characterized some copper(I1) - Schiff base complexes in which the Schiff bases were derived from anthranilic acid and naturally occurring sugars.