Oxidation Mechanisms of Methionine Sulfur

No work seems to have been done on the ability of methionine sulfone to furnish sulfate or taurine. We must simply point out that methionine sulfone cannot replace methionine in the diet of rats (8) and consequently is certainly not converted to methionine by this animal. 

Oxidation of Methionine Sulfur after Previous Transformation of This Compound 

Despite the lack of facts concerning the direct oxidation of methionine sulfur, it seems nearly certain that this direct oxidation plays no role in sulfate formation or contributes only negligibly to the formation of taurine. On the contrary, it appears that the oxidation of methionine sulfur takes place after previous conversion of the methionine to molecules of other types. 

Conversion of Methionine to a-Keto-7-methiolbutyric Acid. Methionine, as an amino acid, can undergo oxidative deamination to the corresponding a-keto acid. In view of the importance of the stereochemical constitution of amino acids in this reaction, the case of the d- and Z-configurations of methionine must be considered separately. 

This specific oxidation of d-methionine by d-amino acid oxidase has been utilized by Duschinsky and Jeannerat (37) for the preparation of Z-methi-onine from the dZ-derivative. 

---