Glycine, also known as glycine or tyrosine, has a molecular formula of C2H5N02. As early as 1820, Bracono had isolated glycine from gelatin. Because it is a crystal with a special sweet taste, it is also called gum. In 1848, the Swedish chemist Berzelius named it glycine. The solid glycine is white monoclinic or hexagonal crystals or white crystalline powder, odorless, non-toxic, relative density 1.1607, melting point 232 ~ 236 ℃ (decomposition). It is easily soluble in water, hardly soluble in ethanol, acetone and ether, slightly soluble in pyridine, and can react with hydrochloric acid to form hydrochloride. This article will briefly introduce the specific applications of glycine in the fields of medicine, food, pesticides, and feed.
Medicine
Amino acid liquid. Glycine is an essential amino acid for the human body. It is used in the formulation of various amino acid infusions. At the same time, it can also be used as a chlortetracycline buffer. At present, the main quality indicators of glycine produced in China can meet the standard requirements of the United States Pharmacopoeia and the British Pharmacopoeia. Every year, China exports a large amount of glycine raw materials to Europe, America and Japan, and imports a large amount of medicinal glycine. It was even discovered that some imported medicinal glycine was originally produced domestically. Although there are problems with regulations and industrial policies, there are also deficiencies in technology and hardware facilities for domestic glycine manufacturers.
Synthetic drugs. As an important pharmaceutical intermediate, glycine can be used to prepare various effective pharmaceuticals. For example, glycine is the main intermediate of the specific drug “L-dopa” for the treatment of Parkinson’s disease. L-DoPa has a special effect on the treatment of pseudohypertrophic dystrophy with weak muscle strength. Glycine can also be used to synthesize important amino acids such as DL-phenylalanine and L-threonine. Glycine is often used as an antacid and antidote. A compound regulator of 30% glycine and 70% calcium carbonate can treat neurogenic hyperacidity; drugs prepared by the reaction of glycine with aspirin and paracetamol can not only improve the solubility of the drug, Increase the efficacy of the drug, but also effectively inhibit the side effects of the drug. The special structure of glycine plays an important role in the synthesis of new drugs.
Health products and reagents. In the field of health care products and biochemical reagents, glycine plays an irreplaceable role in curing protein scarcity and has greater use-value.
Food
Condiment. Adding glycine to food can increase the content of amino acids in the food and improve the nutritional content; at the same time, it can also be used as a condiment, the preparation of refreshing beverages, alcohol-containing ingredients, and saccharin debittering agent; as a sweetener, used in candy and Biscuit making.
Additive. Glycine can be used as a food antioxidant and preservative to extend the shelf life of food. According to statistics, in the United States, the amount of glycine used as a food additive is more than 104t. In Japan, 5% glycine is generally added to commercially available table salt to improve the taste. Adding glycine to monosodium glutamate can improve the taste, extend the shelf life and save food, which has the effect of killing three birds with one stone. As a major MSG country, Japan rarely sells 99.5% MSG on the market, and it is generally a mixture of 90% MSG and 10% glycine. Glycine is also indispensable in the production of famous Japanese pickles.
Pesticides
Glyphosate, a phosphine preparation synthesized from glycine as the starting material, is a highly effective and low-residue herbicide. Because of its broad-spectrum non-selective characteristics, it is very popular among users. It was first successfully developed by Monsanto in the United States in 1971. It was once rated as an excellent pesticide in the United States, and its development speed is very fast, with an annual growth rate of 10%.
Glyphosine. The plant growth regulator glyphosine was also a product developed by Monsanto in 1970. It is formed by the reaction of glycine with phosphorus trichloride and formaldehyde. Applying it to the foliage of plants has the effect of defoliation and ripening. For example, after spraying sugarcane with glyphosine, the sugar content can be increased. After spraying with Glyphosine in the flowering period of cotton, 70% to 90% of the cotton can be defoliated within 7 days, thereby increasing cotton yield.
The above two kinds of pesticides, due to their broad-spectrum, high-efficiency, and non-residual characteristics, have developed rapidly in China in recent years, and the prospects are promising. There are already many pesticide factories in production. For every ton of glyphosate produced, 0.96 tons of glycine is consumed; for 1 ton of glyphosate, 1.3t of glycine is consumed. The largest amount of glycine is used in the production of glyphosate. Also used as a raw material for glyphosate, 99% glycine is used abroad, and 97.5% glycine is used domestically.
Feed
Glycine used in feed additives can not only increase the nutrient content of the feed but also prevent the feed from oxidative deterioration and prolong the fresh-keeping period of the feed. Glycine is an important ingredient in the feed for chicks within 10 weeks of incubation. There is no glycine in the chicken feed formula currently used in China, but it is widely used in Thailand.
The production of canned pets is a very large industry, and the amount of glycine added is quite astonishing. There was once a manufacturer of canned pet feed that ordered 350t of glycine from China at one time. Also, glycine is contained in the feed formulas of cattle and sheep in many countries, and China’s cattle and sheep breeding industry has not yet commonly adopted it, so the application of glycine in this field needs to be further developed in China.
Others
Glycine can also be used as a solvent for organic synthesis, a biochemical reagent, a carbon dioxide removal solvent in the chemical fertilizer industry, and the preparation of a new fluoroamino acid surfactant. Glycine and higher fatty acid salts can be compounded to prepare high-end detergents. Glycine is also widely used in the daily chemical industry for the preparation of hair dyes, cleaning products, cosmetics, etc.
