What Is Cysteine Hydrochloride?

Cysteine hydrochloride is a colorless to white crystal or crystalline powder with a slight special odor and acidity. It has a melting point of 175 ° C (decomposition). Soluble in water, the aqueous solution is acidic, the pH value of 1% solution is about 1.7, and the pH value of 0.1% solution is about 2.4. Also soluble in alcohol, ammonia and acetic acid, insoluble in ether, acetone, benzene and so on. It has reducing properties, has anti-oxidation and prevents non-enzymatic browning.

Cysteine Hydrochloride Properties and Stability

Hygroscopic. Slowly oxidizes and decomposes in the air. The aqueous solution is acidic.

Cysteine hydrochloride storage method

It should be sealed in a cool, dry place and protected from light.

Cysteine hydrochloride synthesis method

1. Dissolve cystine in dilute hydrochloric acid, add tin particles by filtration, and heat to reflux. The reducing solution is diluted with water, the remaining tin particles are removed, saturated with hydrogen sulfide, filtered, the filter residue is washed with a small amount of water, the washing solution and the filtrate are combined, concentrated under reduced pressure, cooled and crystallized, and dried to obtain L-cysteine hydrochloride.

2. Cystine can be obtained by hydrolyzing the -keratin contained in the hair, and then chemically or electrolytically reduced to cysteine, and then hydrochloric acid is added to form a salt. ^[2]