Tyrosine (Tyrosine; Tyr) chemical name for the 2 - amino - 3 - hydroxyphenyl propionic acid, it is a phenolic hydroxyl - containing aromatic polar α - amino acids. Tyrosine is a conditional essential amino acid and ketogenic amino acid.

    Tyrosine is found in the casein from the casein in 1846, a white crystalline powder that crystallizes from water into a needle or sheet. Relative density of 1.456 (20 ℃), isoelectric point 5.66, the absorption capacity of ultraviolet light, at 274nm wavelength of the maximum light absorption, can reduce the phosphomolybdic acid - phosphotungstic acid reagent (Fulin reagent). Melting point: L-body 290 ~ 295 ℃ decomposition (slow heating), 314 ~ 318 ℃ decomposition (rapid heating), racemic 290 ~ 295 decomposition (slow heating), 340 ℃ decomposition (rapid heating). Soluble in water, ethanol, acid and alkali, insoluble in ether. The aqueous solution of the dextral and the tyrosinase showed a reddish effect. L-body can be friction and luminescence, at 170 ℃ and barium hydroxide aqueous solution heated to racemic, tyrosine molecules in the phenolic hydroxyl ortho-prone chemical reaction, and diazobenzenesulfonic acid coupling orange-red material, and boiling Of the role of dilute acetic acid and sodium nitrite was purple or red, with the role of nitric acid was yellow, in the role of sulfuric acid and titanium dioxide was dark orange. Natural tyrosine for the levator, can be hydrolyzed by protein, derived derived.