Methionine derivatives

Methionine is a sulfur-containing amino acid. The synthesis of choline in the body requires the supply of methyl group by methionine, which is a component of lecithin. Lecithin is an indispensable substance for fat transport out of the liver and to remove fat deposits in the liver. Therefore, methionine also has choline-like lipolysis. effect. In addition, methionine supplies sulfur in the body to synthesize non-exogenous amino acid deacetylation, while the latter has detoxification effect, so the drug is clinically a fat-promoting liver-protecting drug. It is suitable for fatty liver and chronic hepatitis and cirrhosis with fatty infiltration. Clinically, it can be used as an adjuvant treatment for alcohol and sulfonamide poisoning. The scientific name is methylthiobutyrate. It is one of the essential amino acids. White flaky crystal or crystalline powder with a specific odor. The molecular weight is 149.21. DL-methionine (racemate) melting point 281 ° C (decomposition). The relative density is 1.340. Soluble in water, dilute acid and dilute alkali solution, slightly soluble in 95% ethanol, insoluble in ether. L-methionine (left-handed body) melting point 280 ~ 281 ° C (decomposition). Soluble in water and hot dilute alcohol. Insoluble in anhydrous ethanol, ether, petroleum ether, benzene and acetone. D-methionine (dextran) melting point 273 ° C (decomposition). Soluble in water, dilute acid and alkali, very slightly soluble in alcohol, insoluble in ether. The general amino acid dextrin is ineffective in biochemistry, with the exception of methionine. Both D-methionine and L-methionine are effective production promoters because D-methionine can be converted to L-methionine in vivo. Therefore, the synthesized DL-methionine is directly applied without precipitation. Methionine is an essential amino acid in animals and is one of the constituent proteins. Can maintain the body's growth and development and nitrogen balance. It cannot be synthesized in animals and must be supplied from outside the body in the form of amino acids or proteins. It is an important feed additive (nutrition enhancer). In food, it is mainly used as a flavoring agent in combination with amino acids such as glycine, alanine, proline and glutamic acid. In medicine, it is one of the main components of amino acid infusion and complex amino acid preparations. Also used to prevent liver disease and arsenic, benzene and other poisoning. It is also used as a protein nutritional supplement for patients with protein deficiency or underabsorption. It is synthesized from acrolein and methyl mercaptan. It can also be obtained by hydrolysis and refining casein.