1.
Org Biomol Chem
; 12(41): 8280-7, 2014 Nov 07.
Article
in English
| MEDLINE
| ID: mdl-25207524
ABSTRACT
Irreversible oxidative damage at both aromatic side chains and dipeptide linkage occurs in the aromatic N- and C-protected dipeptides 7-11 upon exposure to the environmental pollutants NO2Ë and O3. The reaction proceeds through initial oxidation of the aromatic ring by in situ generated NO3Ë, or by NO2Ë, respectively, which leads to formation of nitroaromatic products. The indole ring in Phe-Trp undergoes oxidative cyclization to a pyrroloindoline. An important reaction pathway for dipeptides with less oxidisable aromatic side chains proceeds through fragmentation of the peptide bond with concomitant acyl migration. This process is likely initiated by an ionic reaction of the amide nitrogen with the NO2Ë dimer, N2O4.