Autoxidation of tryptophan in aqueous solutions

Abstract

Autoxidation of tryptophan was investigated in aqueous solutions by the gamma radiolytic technique. The oxygen uptake and formation of peroxide materials was followed as a function of pH, dose rate and concentration of tryptophan. The results obtained indicate that TrpH(OH)OO. radicals react with tryptophan by adduct formation thus propagating autoxidation. The chain propagation length (CPL) for a 2·10–2 mol dm–3 tryptophan solution at pH 9.5 and a dose rate 0.01 Gy s–1 was estimated to be ~ 5.8, which shows that the autoxidation of tryptophan is a short chain reaction.

Keywords

• autoxidation
• tryptophan
• peroxy radicals