Antioxidant properties of aminoethylcysteine ketimine decarboxylated dimer: a review

Abstract

Aminoethylcysteine ketimine decarboxylated dimer is a natural sulfur-containing compound detected in human plasma and urine, in mammalian brain and in many common edible vegetables. Over the past decade many studies have been undertaken to identify its metabolic role. Attention has been focused on its antioxidant properties and on its reactivity against oxygen and nitrogen reactive species. These properties have been studied in different model systems starting from plasma lipoproteins to specific cellular lines. All these studies report that aminoethylcysteine ketimine decarboxylated dimer is able to interact both with reactive oxygen and nitrogen species (hydrogen peroxide, superoxide anion, hydroxyl radical, peroxynitrite and its derivatives). Its antioxidant activity is similar to that of Vitamin E while higher than other hydrophilic antioxidants, such as trolox and N-acetylcysteine.

Keywords: aminoethylcysteine ketimine decarboxylated dimer; reactive nitrogen species; reactive oxygen species; sulfur-containing antioxidants.

Figure 1.

Aminoethylcysteine ketimine decarboxylated dimer.

Scheme 1.

Hypothetical pathway leading to the in vivo synthesis of 1.

Scheme 2.

Oxidation products of aminoethylcysteine ketimine decarboxylated dimer. Reagents and conditions: (i) CuCl₂/t-BOOH or 2,2′-azo-bis-2-amidinopropane-HCl, (ii) hydrogen peroxide.

Scheme 3.

Production of a dimeric form of aminoethylcysteine ketimine decarboxylated dimer in the presence of peroxynitrite. Reagents and conditions: (i) peroxynitrite.