Alias: L-methionine; L-methylthiobutyric acid; L- α- Amino-4-methylthiobutyric acid; L-Methionine 
Molecular formula: C5H11NO2S
Molecular weight: 149.21
Properties: colorless or white shiny flake crystal or white crystalline powder. Slightly special smell. It tastes slightly bitter. Melting point 280-281 degrees (decomposition). It is unstable to strong acid and may cause demethylation. Soluble in water (5.6g/100ml, 30 ° C), warm dilute ethanol, alkaline solution and dilute inorganic acid. It is insoluble in ethanol and almost insoluble in ether.
Use: L-methionine is one of the eight kinds of amino acids that are necessary for human body but can not be synthesized by itself. It is widely used in beverage, food, biochemical reagent, daily life and other fields.