Used as a chiral building block in the synthesis of pharmaceuticals and biologically active compounds. Serves as a reference standard or intermediate in metabolic studies involving sulfur-containing amino acids. Employed in research on oxidative stress due to its formation from methionine under oxidizing conditions. Also utilized in studies related to protein structure and function, where methionine oxidation can affect biological activity. Shows application in the development and validation of analytical methods such as HPLC and mass spectrometry for detecting oxidized amino acids.