Synthesis and antioxidant activity of DOPA peptidomimetics by a novel IBX mediated aromatic oxidative functionalization
Author(s)
Date Issued
2015
Type
article
Volume
5
Issue
74
Start Page
60354
End Page
60364
Journal
Abstract
DOPA peptidomimetics with stable O-C and N-C covalent bonds between amino acid residues have been prepared by aromatic oxidative functionalization of tyrosine with 2-iodoxybenzoic acid (IBX). The reaction involves the Michael-like nucleophilic addition of different oxygen and nitrogen protected amino acids on a reactive DOPA quinone intermediate. Similar results were obtained in heterogeneous conditions using supported IBX-amide for more runs. Among the novel derivatives, compounds containing glycine residues showed a more pronounced antioxidant activity in the 2,2-diphenyl picrylhydrazyl (DPPH) radical scavenging cell free assay. Instead, valine derivatives showed the highest biological effect in L5178Y mouse lymphoma cells, by assessing the ability to reduce H2O2 induced DNA breakage in the alkaline comet assay.