Fumaric acid is one of the substances that form in the cells of humans and other animals in the process of natural metabolism. Its compounds are used in medicine, agriculture, food and chemical industries. In large quantities, this substance is capable of causing negative reactions - allergies and gastrointestinal disorders.
general description
Fumaric acid is an isomer of ethylene-1,2-dicarboxylic acid in the trans configuration (has the arrangement of hydrocarbon substituents on opposite sides of the C â C double bond). This substance was first obtained from succinic acid.
The empirical formula of fumaric acid is: C 4 H 4 O 4 .
In appearance, the compound is an odorless, colorless crystalline powder.
The structural formula of fumaric acid is shown in the figure below:
Acid is found in many plants (European dodder, Corydalis, poppy seeds and others), lichens and fungi, and is also formed during the fermentation of carbohydrates in the presence of smoking aspergillus fungus (aspergillus fumigatus).
The properties
The main physical and chemical properties of fumaric acid are as follows:
- The molecular weight is 116.07 a. eat.
- Solubility: o in alcohols - good; o in water and diethyl ether - weak; o in organic solvents - insoluble.
- Melting point - 296.4 ° C.
- Boiling point - 165 ° .
Fumaric and maleic acids are easily reduced to succinic acid. When oxidized by peroxidic compounds, mesovic acid is formed, and when reacted with alcohols, mono- and diesters (fumarates) are formed.
Biochemistry
Fumaric acid is found in the blood of a healthy person in a concentration of up to 3 mg / l. It is formed as an intermediate in the tricarboxylic acid cycle, during the synthesis of urea and the oxidation of certain amino acids, as well as in human skin under the influence of ultraviolet radiation.
Fumarates play an important role in human tissues during their oxygen starvation. In combination with malic acid and glutamic acid salts, they increase the content of ATP and glycogen, the main form of glucose storage, a universal source of energy for cells. In experiments on rats, it was found that this substance increases the duration of heart contraction during its isolation. With hemorrhagic shock, fumarates increase the survival of animals.
Synthesis
Obtaining fumaric acid on an industrial scale is carried out using the catalytic isomerization of maleic acid in an aqueous solution. In Russia, technical acid is synthesized using this technology, which is not applicable in the food industry and pharmacy due to the presence of salts of heavy metals.
Highly refined edible fumaric acid is made from malic or tartaric acid. This method of manufacturing a substance is associated with technical difficulties (requires laborious multi-stage cleaning) and is more expensive. The quality of technical fumaric acid is more dependent on the purity of maleic acid, which is obtained from maleic and phthalic anhydrides.
Application
In the chemical industry, acid is used to produce the following substances:
- polyester resins;
- synthetic drying oils;
- plasticizers;
In the food industry (additive E297), it is used as an acidifier (a substitute for citric and tartaric acid) in the preparation of drinks, sweets and pastries. At the same time, its consumption is lower than that of analogues. Technical characteristics of food additives are regulated in accordance with GOST 33269-2015.
The medicine
In medicine, this compound is used for the following purposes:
- dimethyl ether (dimethyl fumarate) - treatment of skin pathologies (psoriasis, lichen), multiple sclerosis, baldness, granulomatous diseases; fungicidal, antifungal agent;
- fumaric acid sodium salt - infusion preparations, crystalloid blood substitutes with antihypoxic, antioxidant effects (used for gastroduodenal bleeding, peritonitis, severe thermal injuries, cardiac surgery, acute coronary syndrome, hypovolemia, extensive blood loss, intoxication);
- other derivatives are appetite-boosting drugs, tranquilizers, radiopaque drugs, and rhinitis therapy medications.
Among the drugs of the second group, the most practical applications are Methusol, Mexidol, Confumin and Polyoxyfumarin.
Currently, clinical trials of drugs with fumaric acid for the treatment of pathologies such as:
- malignant neoplasms;
- Huntington's chorea;
- HIV
- malaria.
Animal experiments have shown that a 1% acid solution taken with food for a long time significantly reduces the activity of carcinogens.
Fumaric acid reduces the acidity of the stomach and affects the microflora of the digestive tract. In the intestine, it creates a slightly acidic environment, due to which the growth of pathogenic bacteria is inhibited and favorable conditions are created for the development of lacto-, bifido- and acidobacteria. However, due to the complexity of obtaining highly purified acids for pharmaceutical purposes and in the production of dietary supplements, this compound is rarely used.
Agriculture
In agriculture, fumaric acid is used as an additive in pet food to perform the following functions:
- improving metabolism in stressful situations;
- increased digestibility of feed, increased appetite;
- stimulation of muscle tissue collection, acceleration of bone formation and egg formation in poultry (non-hormonal anabolic);
- increasing the body's defenses during the period of mass diseases and vaccination;
- normalization of intestinal flora, prevention of fungal and bacterial diseases.
Fumaric acid causes accelerated ATP formation, promotes the accumulation of nutrients and ascorbic acid, which is one of the main antioxidants.
Health hazard
High quality purified acid is safe for human health. The harm to fumaric acid is mainly due to the fact that unscrupulous manufacturers use a product of technical quality containing toxic impurities of maleic acid and salts of heavy metals.
Dimethyl fumarate is also used as a cheap biocide to protect leather furniture and shoes from fungal infections during transport. However, as such, the acid can cause severe skin allergic reactions. Thus, in Finland and the UK, more than a thousand consumers demanded monetary compensation for health damage when buying Chinese furniture. Since 2008, a ban has been introduced in European countries on the sale of shoes and furniture impregnated with dimethyl fumarate.