Superoxide dismutase inspired Fe(III)−amino acid complexes covalently grafted onto chloropropylated silica gel – Syntheses, structural characterisation and catalytic activity

In this work the syntheses, structure and SOD activity of covalently grafted Fe(III)-complexes formed with various N- or C-protected amino acid ligands (L-histidine and L-tyrosine) inspired by the active site of the Fe–SOD enzyme are presented. Chloropropylated silica gel was used as support to mimic the proteomic skeleton of the enzyme. Anchored complexes having uniform amino acids as well as their two-component mixtures have been prepared. The products were characterised by mid and far IR and Raman spectroscopies. SOD activities of the substances were determined via the Beauchamp–Fridovich test reaction. It was found that the preparation of covalently anchored Fe(III)−amino acid complexes was successful in many cases. The structures of the anchored complexes and the coordinating groups varied upon changing the conditions of the syntheses. All the covalently immobilised complexes displayed (in some instances appreciable) SOD activity.