Covalently grafted, silica gel supported mixed amino acid iron complexes - Syntheses, structural characterization and catalytic testing

In this work the syntheses of covalently grafted C-protected Fe(III)-amino acid (methylesters of l-histidine, l-cysteine and l-cystine) mixed-ligand complexes with two different amino acid esters are described using chloropropylated silica gel as the support. Conditions of the syntheses were systematically altered and the structural features of the substances obtained were studied by infrared spectroscopy. It was found that in many cases the structures of the anchored complexes and the coordinating groups substantially varied upon changing the conditions of the syntheses. All the covalently anchored materials displayed superoxide dismutase (SOD) activity and some proved to be exceptionally efficient in the biochemical test reaction.