casno. : CAS 1007-42-7/645-35-2
Colorless needle like or flake crystal, softened at 277 ℃ and decomposed at 287 ℃. The solubility in water at 25 ℃ is 41.9g/l, which is slightly soluble in alcohol and insoluble in ether and chloroform. It tastes sweet. The melting point is 282 ° c, and the specific rotation is 12.4 ° (c = 11,6nhcl is extracted from pig blood and bovine blood. The blood powder is prepared by spray drying of pig blood, which is about 18kg per 100kg of pig blood. L-histidine is commonly used as its hydrochloride ([7048-02-4]). The eluent containing l-histidine is concentrated until crystallization occurs, adjusted to ph 2.5 with hydrochloric acid while it is hot, and then ethanol twice the amount of the solution is added immediately. After standing, precipitation and filtration, the crude l-histidine hydrochloride is obtained, and the finished product is obtained by decolorization, recrystallization and drying. L-histidine can also be extracted from the hydrolysate of defatted soybean.