Methionine (2-Amino-4-(methylmercapto)butyric acid, 2-amino-4-(methylsulfanyl)-butanoic acid, Met, M) is a colorless crystalline compound with a specific unpleasant odor. It is soluble in water and boundedly soluble in ethanol; almost insoluble in higher alcohols, diethyl ether, acetone, benzene. Methionine contains asymmetryc carbon atom, thus, there are two optical isomers of methionine - L- and D-forms respectively. Synthetic D,L-methionine is a racemic mixture. L-methionine is an essential amino acid, it cannot be synthesized in humans, therefore it must be obtained from food. Mammals can assimilate D-methionine as well converting it into L-isomer.
Industrially, racemic D,L-methionine is produced from 3-methylthiopropanoic aldehyde.
as an animal feed additive;
as a pharmaceutical to treat and to prevent illness of liver, to prevent atherosclerosis.