Introduction:
L-cystine is a covalently linked dimeric nonessential amino acid formed through the oxidation of cysteine. It is contained in many foods including eggs, meat, dairy products, and whole grains as well as in skin and hairs. L-cystine and L-methionine are the amino-acids required for wound healing and formation of epithelial tissue. It is able to stimulate the hematopoietic system and promote the formation of white and red blood cells. It can also be used as a component of parental and enteral nutrition. It can also be used for the treatment of dermatitis and protection of liver function. L-cystine is manufactured through the enzymatic conversion from DL-amino thiazoline carboxylic acid.