The chemical L-Methionine has a designated molecular formula of C5H11NO2S and a molecular weight of 149.208 g/mol. Synonyms may include: Methionine, L-alpha-Amino-gamma-methylmercaptobutyric acid, L-alpha-Amino-gamma-methylthiobutyric acid, (S)-2-Amino-4-(methylthio)butanoic acid, 2-Amino-4-methylthiobutanoic acid (S)-, L(-)-Amino-gamma-methylthiobutyric acid, 2-Amino-4-(methylthio)butyric acid, (S)-, Butanoic acid, 2-amino-4-(methylthio)-, (S)- (ChemID).