The oxidation products of l-alanyl-l-tyrosine are mainly the oxidation products of cystine and the possible oxidation products of the alanine part. The cystine part contains a sulfhydryl group (-SH), which is easily oxidized, and its oxidation process and products are as follows:
Formation of Disulfide Bonds: A common oxidation reaction is that two sulfhydryl groups are oxidized to form a disulfide bond (-S-S-). After the sulfhydryl groups between or within l-alanyl-l-tyrosine molecules are oxidized, corresponding products connected by disulfide bonds will be generated. For example, a dimeric form of cystine is formed. In the organism, the formation of this disulfide bond is of great significance for the structure and function of proteins, as it can stabilize the three-dimensional structure of proteins.
Oxidation of the Sulfhydryl Group to Sulfinic Acid, Sulfonic Acid, etc.: Under stronger oxidation conditions, the sulfhydryl group of cystine can be further oxidized to higher-valence sulfur-containing groups such as sulfinic acid (-SO₂H) and sulfonic acid (-SO₃H). For example, under some oxidative stress conditions or with the participation of specific oxidases, the sulfhydryl group may be gradually oxidized to the forms of sulfinic acid and sulfonic acid.
The alanine part is relatively stable, but under some extreme oxidation conditions, the amino group (-NH₂) may be oxidized to the nitroso group (-NO), the nitro group (-NO₂), etc., although this situation is relatively rare. In addition, the carboxyl group (-COOH) of alanine may also undergo a decarboxylation reaction under specific conditions, but this usually requires rather special reaction conditions.
