Threonine is an organic compound with the chemical formula C4H9NO3. It has optical activity and is an essential amino acid mainly used in pharmaceuticals, chemical reagents, food fortifiers, feed additives, and other fields.

The physical properties of methionine include its appearance as a white or nearly white powder or crystal, odorless, and slightly sweet taste. It is soluble in water, slightly soluble in ethanol, insoluble in ether, melting point: 270-275 ℃.

In terms of chemical properties, threonine has optical rotation, and its aqueous solution is neutral with stable chemical properties. It is not easily deteriorated under acidic and alkaline conditions. In addition, the molecular formula of threonine is C4H9NO3, with a molecular weight of 119.12. Threonine can undergo esterification reaction with other compounds through the carboxyl group on the hydroxyl group, forming threonine esters.