Sulfur containing amino acid derivatives are mainly derived from three common sulfur-containing amino acids methionine, cysteine and cystine. They can participate in biochemical processes such as trans methyl and trans thio in vivo. At the same time, they also have antioxidant and free radical scavenging functions. They have important application value in medicine and food.

Methionine, cysteine and cystine are common sulfur-containing amino acids, which have important nutritional and physiological functions. Among them, N-acetyl-L-cysteine, glutathione and adenosylmethionine are the most representative. The common feature of these compounds is that they contain sulfur, commonly known as sulfhydryl group. It is because of this active group that these compounds have important physiological functions. Sulfur containing amino acid derivatives are an important research hotspot at present.

N-acetyl-L-cysteine

L-cysteine and its derivatives have a wide range of applications in medicine, such as antitussive, expectorant, anti-inflammatory, antipyretic, analgesic, as well as inhibiting the growth of bacteria and tumor, increasing white blood cells and so on. Therefore, L-cysteine derivatives have attracted great attention of medical circles at home and abroad.

N-acetyl-L-cysteine is a kind of airway mucus dissolving agent, which can decompose white mucus and thick sputum.It can improve the respiratory status of patients; It can also be made into eye drops for the treatment of various keratitis; At the same time, it can be used to treat, prevent or alleviate alopecia due to oxidative damage or chemotherapy. In vivo, it can promote the synthesis of glutathione by participating in various important metabolism, which is of great significance to maintain the reduction state of cells. 

In addition, it can be used as an inhibitor to inhibit tissue and cell necrosis caused by canceration, and to treat Parkinson's disease with external injury, central nervous system and visual tissue injury, and nervous system disorder caused by lipid peroxidation. It is widely used in medicine.

Glutathione

Glutathione is a low molecular weight non protein sulfhydryl compound synthesized by r-glutamylcysteine synthetase and glutathione synthetase. It can be divided into reduced type and oxidized type. It has unique antioxidant and anti-aging properties. In recent years, the demand for glutathione as medicine, health care products and food additives is increasing

Glutathione is an indispensable substance to maintain the stability of the internal environment. Another important function of glutathione is detoxification. At present, glutathione has been widely used in the treatment of toxic diseases and liver diseases abroad. Glutathione can alleviate the side effects of anticancer drugs, especially the damage of bone marrow caused by adriamycin and mitomycin. It is found that glutathione and its derivatives can inhibit HIV and inhibit melanin producing enzymes, namely tyrosinase, and prevent the formation of senile plaques. In addition, glutathione also has good performance in food processing, preservation and antioxidation

With the rapid development of biotechnology, fermentation and enzymatic production have been widely used.

Adenosylmethionine

Adenosylmethionine is a natural substance existing in various organisms. It is mainly used as a methyl donor to participate in various enzymatic methylation processes and as a precursor for the synthesis of taurine, cysteine and glutathione. It can be used in the treatment of depression, especially for patients with chronic liver disease or poor health and the elderly. It has better effect than the commonly used drugs such as imipramine and chlorimipramine, and has no dependence and side effects.