A kind of separation and extraction method of N-acetylneuraminic acid

Abstract

The invention discloses a method for separating and extracting N-acetylneuraminic acid, which comprises the following steps: (1) acidolyzing a solution containing polysialic acid to obtain an acid hydrolyzate; Pass the acid solution through the first membrane to remove solid impurities to obtain the first permeate; pass the first permeate through the second membrane to remove macromolecular impurities to obtain the second permeate; pass the second permeate through the second Three membranes, remove monovalent salts, and collect the retentate; (3) adjust the pH of the retentate to the isoelectric point of N-acetylneuraminic acid, and then remove the multivalent salts by electrodialysis, and pass the solution that removes the multivalent salts through the anion Exchange resin to wash impurities and elute, collect the effluent, concentrate to obtain a concentrated solution; (4) adjust the pH of the concentrated solution obtained in step (3) to 1-3, add a reverse solvent, cool down, precipitate crystals, centrifuge, wash and dry , that is. The whole separation process is simple to operate, the purity of the crystal product is over 99%, and the yield is over 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...

AI Technical Summary

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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