Oxidation of tryptophan by benzimidazolium dichromate

Abstract

In order to determine a likely mechanism, tryptophan oxidation with benzimidazolium dichromate (BIDC) in an acid medium utilizing sulfuric acid has been investigated at 313 K. First order dependence is demonstrated by the calculated pseudo-first order rate constant, which is found to be independent of the oxidant’s initial concentration. Additionally, the reaction exhibits first order behavior for both sulfuric acid and tryptophan. The rate of reaction is unaffected by an increase in ionic strength and is lowered by a decrease in the medium’s dielectric constant. Since acrylonitrile is not polymerizing, there is no chance of a free radical mechanism. The two electron transfers involved in the mechanism are confirmed when the concentration of manganous sulphate increases because it slows down the rate of reaction. A suitable mechanism and rate law have been derived from the experimental observations. The oxidation reaction yields carbon dioxide, ammonia, and indole-3-acetaldehyde as its products.

Keywords

• Kinetics
• Oxidation
• Tryptophan
• Benzimidazolium dichromate