PL192329B1 - Method of obtaining starch derivatives - Google Patents

Abstract

A method of producing starch derivatives, characterized in that the starch is degraded with NaOH in the amount of 5-25% by weight at the temperature of 85-95 ° C for 2-6 hours, then the starch degradation product is reacted with acrylamide in an amount of 5-50% by weight with respect to starch, at 45-55 ° C for 90-180 minutes, and the reaction product optionally subjected to purification, preferably with methanol

Description

Description of the invention

The subject of the invention is a method for the production of starch derivatives, forming 20-40% aqueous solutions of not very high viscosity, intended for the purification of proteins, enzymes and viruses using the technique of two-phase systems.

The turbulent development of polymer materials in the twentieth century was one of the most important reasons for the development of all the most modern branches of science and technology, such as: the space industry, nuclear industry, modern means of transport, microelectronics, construction, household, etc. However, the negative aspect of the production of thousands of tons of polymer materials was their pollution of the natural environment. The problem of utilization of plastic waste has become particularly troublesome.

This disadvantageous disadvantage of polymers in combination with the so-called the Green Revolution has increased interest in polymers of natural origin.

Starch is a natural, cheap, renewable and environmentally friendly polymer. It occurs in the form of grains made of a high-molecular carbohydrate substance. The grains contain a hardly swelling in water amylopectin shell - approx. 80%, inside which there are layers of water-soluble amylose - approx. 20%.

Starch is widely used in the national economy and household. The largest amounts of it are consumed by the paper, food and textile industries.

It is a component of some building insulation materials, adhesives, flocculants, ceramics and explosives, medicines, cosmetics, etc.

In some applications, taking advantage of its natural gel-forming and thickening properties, it is used in its natural form, but in most cases it is used in a processed form.

Recently, the possibility of using starch polymers in biotechnology for the purification of various substances such as enzymes, proteins and viruses was discovered using the technique of two-phase systems.

Aqueous two-phase systems have found wide application in biochemical scientific research on the separation and purification of macromolecules, cells and cell particles. In recent years, they have also found applications in various branches of biotechnology. The above phase systems have been used on a large scale for enzyme purification, interferon purification, collocation purification, analytical applications and extractive bioconversion.

For the separation of substances in the laboratory, polymer-polymer systems, especially those containing fractionated dextran and polyethylene glycol (PEG), have been used to great effect. Inexpensive PEG-salt systems are used for the large scale enzyme isolation. This choice was dictated by economic factors due to the high cost of fractionated dextran (produced by bacteria). However, the properties of the PEG-salt systems severely limit their usefulness for biotechnology applications mainly due to their high salt concentration. Polymer systems are generally much more useful and allow processes to be run with a low salt concentration.

The current solutions aimed at obtaining two-phase systems that can be used in biotechnology are based on the use of dextran - a natural polymer formed with the participation of bacteria.

In works disclosed in Albertsson P., Partition of Cell Particles and Macromolecules, 2nd Edn, Almqvist & Wiksell, Stockholm, (1971), Albertsson P., Andersson B., Larsson C., Akerlund H., Methods Biochem. Anal., 28, 115-150, (1981), Veide A., Smeds A., Enfors S., Biotechnol Bioeng., 25, 1789-1800, (1983) two-phase for the purification of proteins, enzymes and viruses.

The disadvantage of fractionated dextran is its high cost, which makes it impossible to use it on a larger scale. Crude dextran produces solutions that are too viscous, which cannot be used to form two-phase systems due to the excessively long phase separation time of such systems.

It turned out that the above drawbacks can be avoided and a new type of natural polymers based on modified starch can be obtained.

The method of producing starch derivatives according to the invention consists in degrading the starch with NaOH in an amount of 5-25% by weight at the temperature of 85-95 ° C for 2-6 hours, and then the starch degradation product is reacted with acrylamide in the amount of 5-50% by weight

With respect to starch, at a temperature of 45-55 ° C for 90-180 minutes, and the reaction product is optionally purified, preferably with methanol. In the purification of the reaction product with methanol, 200-5000 ml of methanol are preferably used per 200 g of a 10% solution of acrylamide starch derivative.

When purifying the product with methanol, 1-10 g of NaCl may additionally be used per 200 g of a 10% acrylamide starch derivative solution.

The new acrylamide starch derivatives (APS) are cheap, highly soluble in water (20-40%) and create low viscosity solutions. They are relatively easy to create two-phase systems, especially in the presence of NaCl, with many polymers, including polyethylene glycol, vinylimidazole (VI) and vinyl caprolactam (VCL) copolymers. The separation time of the two phases of such systems is ideal, ranging from 0.5 to 6 hours.

The subject matter of the invention is illustrated in the examples of its embodiments which, however, do not limit its scope.

The symbol "S / AA" indicates the weight ratio of starch to acrylamide.

P r z k ł a d 1. In a three-neck flask with a capacity of 250 ml with a stirrer, reflux condenser and thermometer, 20 g of starch and 180 g of water were mixed. The mixture was heated to 85 ° C, in which it swelled and gelled. An aqueous 40% NaOH solution (3.75 g NaOH in 5.6 g water) was then added dropwise with vigorous stirring. The temperature of the reaction mixture was raised to 90 ° C and the mixture was kept at this temperature for an additional 4 hours. After this time, the contents of the flask were cooled to 48 ° C and a 50% aqueous solution of acrylamide (3.75 g of acrylamide in 3.75 g of water for the sample S / AA = 80/15 or 15 g of acrylamide in 15 g) was introduced into it. water for sample S / AA = 80/60). The whole was kept at the temperature of 48 ° C for 2 hours. After this time, the reaction product was neutralized with 10-15% HCl to pH 7 and purified by precipitation in 4000 ml of methanol. The precipitated and then dried polymer was redissolved in 180 g of water, 3 g of NaCl was added and precipitated once more in 4000 ml of methanol. The product thus purified was dried at 80 ° C.

Example II. In a three-neck flask with a capacity of 250 ml with a stirrer, reflux condenser and thermometer, 20 g of starch and 180 g of water were mixed. The mixture was heated to 90 ° C, in which it swelled and gelled. Then, while stirring vigorously, an aqueous 40% NaOH solution (4 g NaOH in 6 g water) was added dropwise. The temperature of the reaction mixture was raised to 90 ° C and the mixture was kept at this temperature for an additional 3 hours. After this time, the contents of the flask were cooled to 50 ° C and a 50% aqueous solution of acrylamide (3.75 g of acrylamide in 3.75 g of water for the sample S / AA = 80/15 or 15 g of acrylamide in 15 g) was added to it. of water for the sample S / AA = 80/60). The whole was kept at 50 ° C for 1.5 hours. After this time, the reaction product was neutralized with 10-15% HCl to pH 7 and purified by precipitation in 4000 ml of methanol. The precipitated and then dried polymer was redissolved in 180 g of water, 3 g of NaCl was added and precipitated once more in 4000 ml of methanol. The product thus purified was dried at 80 ° C.

P r x l a d III. In a three-neck flask with a capacity of 250 ml with a stirrer, reflux condenser and thermometer, 20 g of starch and 180 g of water were mixed. The mixture was heated to 85 ° C, in which it swelled and gelled. Then, with vigorous stirring, an aqueous 33% NaOH solution (3 g NaOH in 6 g water) was added dropwise. The temperature of the reaction mixture was kept at this temperature for an additional 6 hours. After this time, the contents of the flask were cooled to 45 ° C and a 50% aqueous solution of acrylamide (3.75 g of acrylamide in 3.75 g of water for the sample S / AA = 80/15 or 15 g of acrylamide in 15 g) was introduced into it. water for sample S / AA-80/60). The whole was kept at 45 ° C for 2 hours. After this time, the reaction product was neutralized with 10-15% HCl to pH 7 and purified by precipitation in 4000 ml of methanol. The precipitated and then dried polymer was redissolved in 180 g of water, added 3 g of NaCl, and precipitated once more in 4000 ml of methanol. The product thus purified was dried at 80 ° C

P r x l a d IV. In a three-neck flask with a capacity of 250 ml with a stirrer, reflux condenser and thermometer, 20 g of starch and 180 g of water were mixed. The mixture was heated to 85 ° C, in which it swelled and gelled. Then, while stirring vigorously, an aqueous 40% NaOH solution (3.75 g NaOH in 5.6 g water) was added dropwise. The temperature of the reaction mixture was raised to 90 ° C and the mixture was kept at this temperature for an additional 4 hours. After this time, the contents of the flask were cooled to 50 ° C and a 50% aqueous solution of acrylamide (3.75 g of acrylamide in 3.75 g of water for the sample S / AA = 80/15 or 10 g of acrylamide in 10 g) was introduced into it. of water for the sample S / AA = 80/40). The whole was kept at 50 ° C for 2 hours. After this time, the reaction product was neutralized with 10-15% HCl to pH 7 and purified by precipitation in 4000 ml of methanol. Precipitated

The dried polymer was then redissolved in 180 g of water, 3 g of NaCl were added and precipitated once more in 4000 ml of methanol. The product thus purified was dried at 80 ° C,

P r z k ł a d V. In a three-neck flask with a capacity of 250 ml with a stirrer, reflux condenser and thermometer, 20 g of starch and 180 g of water were mixed. The mixture was heated to 90 ° C, in which it swelled and gelled. Then, while stirring vigorously, an aqueous 40% NaOH solution (3.75 g NaOH in 5.6 g water) was added dropwise. The temperature of the reaction mixture was raised to 90 ° C and the mixture was kept at this temperature for an additional 4 hours. After this time, the contents of the flask were cooled to 55 ° C and a 50% aqueous solution of acrylamide (3.75 g of acrylamide in 3.75 g of water for the sample S / AA = 80/15 or 10 g of acrylamide in 10 g) was introduced into it. of water for the sample S / AA = 80/40). The whole was kept at the temperature of 48 ° C for 2 hours. After this time, the reaction product was neutralized with 10-15% HCl to pH 7 and purified by precipitation in 4000 ml of methanol. The precipitated and then dried polymer was redissolved in 180 g of water, added 3 g of NaCl, and precipitated once more in 4000 ml of methanol. The product thus purified was dried at 80 ° C.

Claims (3)

Patent claims The method of producing starch derivatives, characterized in that the starch is degraded with NaOH in an amount of 5-25% by weight at the temperature of 85-95 ° C for 2-6 hours, and then the starch degradation product is reacted with acrylamide in an amount 5-50 wt.% With respect to starch, at 45-55 ° C for 90-180 minutes, and the reaction product is optionally subjected to purification, preferably with methanol. 2. The method according to p. A process as claimed in claim 1, characterized in that 200-5000 ml of methanol are used for the purification of the reaction product with methanol per 200 g of a 10% solution of acrylamide starch derivative. 3. The method according to p. A process according to claim 1, characterized in that, when purifying the product with methanol, additionally 1-10 g of NaCl are used per 200 g of a 10% solution of acrylamide starch derivative.