Alginic acid production in the world. Alginates in medicine and cosmetology. Alginic acid e400

Alginic acids (from lat. alga - sea grass, algae) are polysaccharides, the molecules of which are built from the residues of β-D-mannuronic and β-L-guluronic acids, which are in the pyranose form and linked into linear chains by glycosidic bonds. Polymannuronic acid blocks impart viscosity to alginate solutions, guluronic acid blocks are responsible for gel strength and specific binding of divalent metal ions. Alginates are amorphous colorless or slightly colored substances. Poorly soluble in cold water, soluble in hot water and alkali solutions; when acidified, the solutions form gels. Alginates can be obtained from more than 300 species of brown algae, the structural elements of the cell walls of which they are, in particular from Laminaria hyperborea, Macrocystis pyrifera and Ascophyllum nodosum, to a lesser extent from L. digitata, L. japonica, Ecklonia maxima, Lessonia nigrescens and some Sargassum species.

Application of alginates

Salts of alginic acids - thickeners, stabilizers of suspensions and pastes. The hydrophobic properties of water-insoluble alginates are used in the manufacture of waterproof yarn, fabrics, and leather clothing. Alginates are used in the textile industry to thicken paints. In the pulp and paper industry, it is used for finishing paper. In the food industry for encapsulation, which increases the shelf life of products, a moisture-retaining agent that regulates the activity of water in the product and thus prevents drying out. Adding 0.1-0.2% sodium alginate to sauces, mayonnaises and creams improves their whipping, uniformity, and prevents delamination. The introduction of 0.1-0.15% sodium alginate into jams and jams prevents them from sugaring. Gelling agents in the production of ice cream and other dairy products. Used in the manufacture of pharmaceuticals and cosmetics.

Alginic acids and alginates have a number of remarkable features that allow them to be used in medicine:

• - ion-exchange properties that underlie the protection of the body from salts of heavy metals;
• - ability to eliminate radionuclides;
• - anti-allergic and immunomodulatory properties associated with the ability to absorb immune complexes, immunoglobulin E, stimulate the secretion of immunoglobulin A;
• - the ability to restore the functional activity of macrophages, which ensures their antimicrobial, antifungal and antiviral activity;
• - pronounced regenerative and cytoprotective effect for damaged tissues;
• - antireflux action;
• - high sorption activity;
• - action that restores and stimulates intestinal motility and enveloping action due to swelling in the lumen of the gastrointestinal tract;
• - weak osmotic laxative effect.

We bring to your attention a number of articles about the unique healing properties of seaweed (based on the book of the same name by L.A. Zubov, candidate of medical sciences)

• Precious substances - micro and macro elements, vitamins in algae.
• Prevention of iodine deficiency or nutrition for the thyroid gland.
• Help the immune system, immune regulators. Allergy prevention.
• The use of algal preparations for the treatment of the stomach, with diseases of the gastrointestinal tract.

Alginates. The use of alginic acid in pharmacology.

In the 19th century, scientists first discovered that some marine plants contain alginic acid. A few years later, this acid was called algal. It is thanks to this polysaccharide that sea kale has many healing properties. Laminaria contains 15 to 30% alginic acid. Alginic acid, like other polysaccharides of natural origin - cellulose, pectins, starch, has many useful properties, but at the same time it is also distinguished by its unique properties.

What is it about this alginic acid?

Alginic acid is a polysaccharide. The wide use of marine polysaccharides is due to such properties as the ability to swell, as viscosity, interaction with various structures. Alginic acid is a long chain of polyuronic acids that make up algal fibers. These fibers consist of two monomeric units - guluronic and mannuronic acids in different proportions. Algae fibers are not digested and are excreted by the intestines. Alginic acid is insoluble in most organic solvents, including water, like other natural polymers. Alginates, salts of alginic acid, behave differently. Potassium alginate, sodium alginate and magnesium alginate are very soluble in water and form viscous solutions. This property of alginates allows them to be used as thickeners, stabilizers in the production of food products and medicines. If sodium apginate is added to calcium ions, a gel is easily formed. Alginic acid also has the ability to adsorb water weighing 300 times its own.

Ion-exchange properties are the same for alginic acid. Rows of cations were revealed in order of increasing their relationship with alginic acid - if any cation binds to it more strongly, then it displaces another cation from the compound. For example, copper, lead, strontium, barium cations have a higher affinity than calcium cations for alginic acid, so calcium cations will be displaced from calcium apginate by lead cations and the latter will themselves bind tightly to alginic acid.

Brown seaweed is the only source for the production of alginic acid. Every year, 25 thousand tons of alginic acid are produced on the planet. Alginic acid and its derivatives have found application in perfumery and cosmetics, medicine, winemaking, textile, food and other industries.

Recently, the demand for alginates in medicine has increased dramatically. In medicine, alginates are used as biologically active substances in medical preparations or excipients for finished medicines. Due to the property of alginates to swell in water and form gel-like solutions. they are used as disintegrants in the composition of tablets, which increases the absorption of tablets in the gastrointestinal tract. Apginic acid is used in 20% of tablet medicines. "Pentalgin", for example, during storage quickly cements, and therefore the time of its dissolution in the stomach increases to 60 minutes, and we need to remove the headache quickly. When alginic acid is added to Pentalgin, the dissolution time is reduced to 6-10 minutes.

The most convenient form for medicines is capsules, gastric juice does not destroy the medicine, and it is absorbed through the intestines in full. In the production of capsules, gelatin is usually used, but if alginates are added to the gelatin mass, capsules are obtained with selective solubility in the areas of the gastrointestinal tract necessary for the drug, while the drugs have a pronounced effect and help to weaken the effect of gastric juice on the active components of the drug. At the same time, the cost of alginic acid and its salts is much lower than other plant extracts used in the manufacture of medicines. Algae components can completely replace expensive extracts. In dentistry, sodium alginate is used to remove imprints of teeth in the manufacture of prostheses.

These and many other properties of alginates are successfully used in pharmaceuticals. In the following articles, we will talk about how alginic acid derivatives help maintain health in an unfavorable environmental situation, protect against modern diseases - oncological, gastrointestinal, cardiovascular, renal, and strengthen immunity.

Seaweed, mainly brown - kelp, fucus, spirulina, are a source of substances used in various industries, including medicine and cosmetology. Among the substances that have found application in the composition of various therapeutic and prophylactic drugs and cosmetics, one can name agar, alginic acid and its salts, mannitol.

Since the discovery of alginic acid in algae, many of the healing properties of seaweed have been attributed to the presence of this acid. In addition to alginic acid, seaweed is rich in other biologically active substances: trace elements, vitamins.

Alginic acid is a polysaccharide, built from the residues of uronic acids - mannuric and guluronic. Alginic acids are insoluble in water, but are highly hygroscopic, that is, they are able to bind large amounts of water. Salts of alginic acid (sodium, potassium, magnesium alginates) dissolve in water to form viscous solutions. This property allows the use of alginates as thickeners, stabilizers, binders in the production of food products, as adjuvants that accelerate the absorption of certain dosage forms in the gastrointestinal tract, to impart a certain consistency to cosmetics. In addition, alginates are also suppliers of active biological substances in the composition of medical and cosmetic preparations.

The use of alginates in medicine.

Alginates are important for medical practice, since they have the ability to prevent the development of many diseases - oncological, cardiovascular, renal, gastrointestinal, and are able to strengthen the immune system.

The immunostimulating effect of alginates is associated with the activation of phagocytosis (which increases antiviral and antimicrobial reactions), with the adsorption of an excess amount of immune complexes in the blood (thus preventing the development of inflammatory and allergic reactions). Alginates increase the barrier function of the skin and mucous membrane of the respiratory tract and gastrointestinal tract in relation to the pathogenic action of microorganisms by stimulating the synthesis of antibodies (immunoglobulins A) of local specific protection. By stimulating phagocytosis, they also have an antitumor effect. Salts of alginic acid are sorbents of cholesterol and fatty acids, thereby eliminating the main possible causes of atherosclerosis. Alginates are able to bind and remove heavy metal ions from the body, providing an anti-radiation effect. They are also included in preparations for the treatment of peptic ulcers of the gastrointestinal tract, as they are able to stop bleeding, have antacid properties, and stimulate the healing of peptic ulcers. For the treatment of wounds of various origins, burns, trophic ulcers, dressings with an alginate coating are produced. Such dressings have draining properties, accelerate wound cleansing, protect the wound from infection and injury, contribute to the favorable course of the wound process and healing.

The use of alginates in cosmetology.

Salts of alginic acid are the main components of alginate masks, which are widely used in salon programs for face and body skin care. Alginates are a powder that, immediately before applying the mask, is diluted with water or a special serum until a creamy consistency is obtained. The mask is applied to the area of ​​care, hardening, the mask forms a rubber-like air- and gas-tight film that fixes the contours of the face and body. Then this film is carefully removed in a uniform layer. On the face and neck, the mask is applied along the massage lines with a spatula from the bottom up, while the mask fills in all the irregularities of the skin, providing a pronounced lifting effect, reducing wrinkles of the forehead, neck, and nasolabial folds.

Alginate masks in their pure form have positive cosmetic effects: they tighten the skin, improve blood circulation, smooth mimic wrinkles, but the introduction of additional biological components (essential oils, extracts of medicinal plants, collagen, anti-inflammatory substances, etc.) into them makes it possible to achieve a higher efficiency of their use. . Depending on the active components introduced into the composition, alginate masks can predominantly have nourishing, moisturizing, cleansing, whitening properties, have anti-aging, anti-cellulite, and other effects.

The most important property of alginate masks is their ability to enhance the effect and increase the flow of active substances into the deep layers of the skin of serums applied under the alginate mask. Therefore, the choice of serum of a certain direction will largely determine the final result of the procedure, for example, moisturizing or anti-wrinkle serum will increase the effectiveness of a moisturizing or lifting procedure, respectively. Alginate masks can be the final stage of procedures such as mesotherapy, photorejuvenation, peeling to eliminate skin irritation.

Materials used in the preparation of the article:
• 1. Bogdanova T.Ya., Kashkin A.P. and others. Alginic acid in infectious diseases // St. Petersburg: NIIVS.
• 2. Zubov L.A., Savelieva T.A. Healing gift of the sea // Arkhangelsk: AOWC, 1997.

Description

Alginic acid is insoluble in water and in most organic solvents. One part of alginic acid adsorbs 300 mass parts of water, which leads to its use as a thickener in the food industry, in particular in the preparation of ice cream, syrups, sauces and cheeses.

Alginic acid is a heteropolymer formed by two residues of polyuronic acids (D-mannuronic and L-guluronic) in different proportions, varying depending on the specific type of algae. Alginates in the human body are not digested and are excreted through the intestines.

Alginic acid and alginates are widely used in medicine (as an antacid) and as food additives (thickeners).

Alginates

Salts of alginic acid - alginates, in particular sodium alginate (E401), potassium alginate (E402) and calcium alginate (E404) are used as food additives.

Potassium and sodium alginates form colloidal solutions in water, unlike insoluble alginic acid. The addition of aqueous solutions of sodium alginate to solutions containing calcium ions (eg calcium chloride) results in the formation of insoluble calcium alginate gels. This property of alginates is used to create microcapsules and artificial cells, as well as to create some food products (for example, artificial red caviar based on alginates). The successful use of alginate capsules containing live bacteria - probiotics for their delivery to the intestines has been shown.

In dentistry, alginate with additives is used as an impression mass - for making an impression of the jaw, with further casting of a plaster model. Silicone impression masses are also used for similar purposes.

Alginates are characterized by the following types of biological activity:

• antimicrobial action, suppression of the activity of facultative flora (candida and staphylococci);
• maintaining the natural intestinal microflora;
• hemostatic effect (hemostatic, due to which they are effective in erosive and ulcerative processes in the gastrointestinal tract);
• improvement of motor function of the intestine (which contributes to the prevention of constipation);
• enveloping action;
• weakening of pathological reflexes, including pain ones;
• slowing down the rate of absorption of glucose from the small intestine;
• immunomodulatory action;
• hypolipidemic effect (decrease in the level of atherogenic blood fractions, prevention of atherosclerosis);
• antitoxic and antiradiation action - effective and safe binding of heavy metals (lead, mercury), radioactive compounds (cesium, strontium) and their removal from the body.

Alginic acids- the main structural component of the cell walls of brown algae Laminaria ,macrocystis pyrifera ,Fucus ,Phaeophyta and others. The content of alginic acids in brown algae can be 20 - 40% by weight of air-dry raw materials. Alginic acids are also produced by some types of bacteria, mainly representatives of the genera Azotobacter vinelandii and Pseudomonas .

History reference. Alginic acids were first isolated over 100 years ago from several brown algae. Later, these polysaccharides were found in all types of brown algae, without exception, where they are components of the cell wall and intercellular substance.

In 1982, rather unexpectedly, alginic acids were discovered in a species of calcareous red algae belonging to the family So r a llina ceae . In the works of Usov A.I. with collaborators it has been shown that the presence of alginates is indeed a distinguishing feature of representatives of this family. These polysaccharides were not found in other plants.

Receipt

For the industrial production of alginic acids, brown seaweeds are used, mainly of the laminaria genera ( Laminaria) and macrocystis ( macrocystis). Algae biomass is pre-treated with a dilute aqueous solution of mineral acid to remove low molecular weight compounds, divalent cations and associated water-soluble polysaccharides (laminarin, fucoidin). Alginic acids from the purified biomass are extracted with a solution of soda or alkali and precipitated from the extract with ethyl alcohol, acidification or conversion into an insoluble Ca 2+ -salt.

The preparative yield of alginic acids is used to assess their content in the algae biomass.

Chemical structure and molecular structure

Alginic acids are polyuronides, i.e. polysaccharides, the molecules of which are built from residues uronic acids. In the composition of alginic acids were found at first D -mannuronic(Fig. 1 a), and then L -guluronic(Fig. 1 b) acids.

Using partial hydrolysis and isolation of the corresponding disaccharide, it was found that the residues of both uronic acids are part of the same polymer molecule. According to modern concepts, based on numerous results of methylation, periodate oxidation, and a number of physicochemical methods of structural analysis (mainly NMR spectroscopy), alginic acid macromolecules are linear and built from units of residues  - D -mannuronic(M) and  - L -guluronic acid(G) located in pyranose form and related  -(1→4)-glycosidic bonds(Fig. 2).

Bacterial alginic acids differ from algal ones in that some of their hydroxyl groups are usually acetylated, and acetyl groups occupy positions C 2 or C 3 (sometimes both at once) in the residues - D-mannuronic acid.

Alginic acids from different sources may differ in the ratio of mannuronic and guluronic acids (value M/ G), as well as the distribution of monomer units along the polymer chain. Using partial hydrolysis and fractionation of oligomeric products, it was found that the distribution of monomer units in macromolecules of alginic acids is block character, i.e. there are areas built almost exclusively from the remains of any one uronic acid ( M-blocks and G-blocks). These blocks are separated by regions that contain approximately equal amounts of both monosaccharides arranged in a more or less strictly alternating sequence ( MG-blocks). Such a peculiar structure is the result of a stepwise biosynthesis of polysaccharide molecules, in which linear polymannuronans are first formed, and then epimerization occurs in these polymeric precursors at the C atom of the 5 part of the residues - D-mannuronic acid under the action of a specific enzyme - polymannuronan-C (5) -epimerase, which leads to the appearance of residues in the polymer - L-guluronic acid.

The size and relative position of individual blocks have a decisive influence on the properties of alginic acids and their salts - alginates. Remains- D-mannuronic and - L-guluronic acids, with all their structural similarity (these residues differ only in the configuration at one of the asymmetric centers, namely at the C 5 atom (see Fig. 1)) have the opposite conformation of the pyranose ring (respectively 4 FROM 1 and 1 C4), which leads to a completely different shape of polymer molecules in the regions poly-M and poly-G(Fig. 3).

In addition, hydroxyl groups - D-mannuronic acid are located diequatorially, which leads to the association of units of monosaccharide residues into an elongated chain, the structure of which is called "tape". Hydroxyl groups of residues - L-guluronic acid are located diaxially. When they are combined into a chain, a “ribbon” structure is also formed, but of a folded type. Since the neighboring units of the G-blocks are close enough to each other, hydrogen bonds are formed between the OH groups. They stabilize the chain, which makes the G-blocks more rigid in comparison with the M-blocks, which do not have intramolecular H-bonds.