Separation and extraction method for N-acetylneuraminic acid

Abstract

The invention discloses a separation and extraction method for N-acetylneuraminic acid. The separation and extraction method comprises the following steps: (1) carrying out acidolysis on a solution containing polysialic acid so as to obtain an acidolysis solution; (2) allowing the acidolysis solution obtained in the step (1) to pass through a first membrane to remove solid impurities so as to obtain a first permeate, allowing the first permeate to pass through a second membrane to remove macromolecular impurities so as to obtain a second permeate, allowing the second permeate to pass through athird membrane so as to remove monovalent salt, and collecting a trapped fluid; (3) adjusting the pH value of the trapped fluid to an N-acetylneuraminic acid isoelectric point, carrying out electrodialysis to remove multivalent salt, allowing a multivalent salt removed solution to pass through anion exchange resin for impurity washing and elution, collecting an effluent, and carrying out concentrating so as to obtain a concentrated solution; and (4) adjusting the pH value of the concentrated solution obtained in the step (3) to 1-3, adding a reverse solvent, carrying out cooling until a crystal is extracted, and carrying out centrifuging, washing and drying. The whole separation process is simple to operate; the purity of a crystal product is 99% or above; and the yield is greater than 90%.

Description

technical field [0001] The invention belongs to the technical field of separation and purification, and more specifically relates to a separation and extraction method of N-acetylneuraminic acid. Background technique [0002] Sialic acid is the main nutrient component of bird's nest. It is a derivative of 9-carbon monosaccharide. Its name comes from Greek. It is a negatively charged ion that can make saliva feel smooth. At present, cognition is the transmitter of gangliosides and is a component of the brain. Sialic acid can prevent the invasion of germs. Babies have a high content of sialic acid in infancy, which is of great significance to their physical development. [0003] The production methods of sialic acid are mainly fermentation method, enzyme synthesis method and natural product extraction method. In the prior art, there is disclosed a method for continuous separation of sialic acid, which requires ethanol for polysialic acid precipitation, and acid hydrolysis aft...

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Problems solved by technology

In the prior art, there is disclosed a method for continuous separation of sialic acid, which requires ethanol for polysialic acid precipitation, and acid hydrolysis after preliminary purification by cetylpyridine, and then anion and cation exchange resin, and the eluent is frozen After drying, crystallize under the ternary system of ethanol, water, and ethyl acetate. The separation cost of the whole process is high and the yield is only about 50%.

Another literature report, concentrated acidification crystallization after simply passing through membrane filtration, the experiment proves that this method contains too many impurities in the solution, the solution viscosity is too high, the crystallization is difficult to complete, and the product purity is low, the product pigment content is large, and the overall yield is less than 70%

[0004] Due to the small size of Escherichia coli and the high viscosity of the fermentation broth, it is very difficult and inefficient to separate solids and liquids by conventional methods such as centrifugation, membrane filtration, and plate-and-frame filtration. Therefore, it is necessary to develop a new method to Improve separation yield, efficiency and purity of obtained products

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