Preparation method for dextran with weight average molecular weight of 3000-6000Da

Abstract

The present invention utilizes dextran enzyme to direct degrade dextran with a weight average molecular weight of 7000-80000Da including micro-molecular dextran (i.e., dextran 10), small molecular dextran (i.e., dextran 20), low molecular dextran (i.e., dextran 40), middle molecular dextran (i.e. dextran70) to special micro-molecular dextran with a weight average molecular weight of 3000-6000Da. The special micro-molecular dextran can be used as a raw material for preparation of special micro-molecular iron dextran. The preparation method is mild and safe in reaction conditions, less in three wastes, easy to control the weight average molecular weight of the final product dextran, narrow in molecular weight distribution, simple in process, rare in dextran loss, and low in production costs. The product after degradation does not need to be processed, and can be directly used for oxidation and complexation to produce high-quality special micro-molecular iron dextran.

Description

technical field [0001] The invention relates to a preparation method of dextran, also known as dextran, specifically a preparation process of ultra-micromolecular dextran with a weight-average molecular weight of 3000-6000Da, which is mainly used as the main raw material of iron dextran iron supplement and belongs to fine chemical industry field. Background technique [0002] The invention relates to a preparation method of ultramicromolecular dextran (weight-average molecular weight 3000-6000Da), a raw material for producing ultramicromolecular dextran iron, which is used for preventing and treating iron deficiency anemia of piglets and livestock. [0003] A large number of studies have shown that there is only about 50 mg of iron in piglets at birth, and they need 7 mg of iron per day to meet their growth needs, while piglets can only obtain 1 mg of iron from sow milk per day. If it can be supplemented, it will not be able to meet its growth needs and produce iron deficie...

AI Technical Summary

Problems solved by technology

The reason why domestic manufacturers cannot produce such ultra-micromolecular iron dextran is mainly because although domestic dextran manufacturers produce high-molecular dextran (molecular weight is about 5×108Da) by enzymatic methods, they use acid hydrolysis to degrade high-molecular dextran , and then use ethanol fractional precipitation to obtain dextran with different molecular weights. The production cost is high, and it is extremely difficult to obtain ultra-micromolecular dextran, so it is impossible to provide ultra-micromolecular dextran to downstream manufacturers (ie, iron dextran manufacturers).

[0004] In order to solve the preparation problem of ultra-micromolecular dextran (weight-average molecular weight is 3000-6000Da), Chinese patent No. CN101205256A proposes the use of membrane separation and classification in the production process of dextran 5 (weight-average molecular weight is 4500-5500Da), instead of alcohol classification. Separation, although alcohol is not used in the production process, the molecular weight degradation of dextran is still treated with acid heating. The disadvantage of this method is that it needs to be neutralized with alkali after acid treatment. Sodium solution increases the treatment of "three wastes". Moreover, the amount of acid and alkali is large, which increases the production cost. At the same time, the acid hydrolysis method needs to be carried out at a higher temperature, the degradation time is also long, and the energy consumption is high. The dextran product obtained by this method The molecular weight distribution of dextran is also wide, and to obtain dextran with narrow molecular weight distribution, the loss of dextran is relatively large, and the yield is relatively low

Chinese CN1041762A patent proposes to use alkali hydrolysis to degrade dextran with larger molecular weight, the disadvantage of this method is basically the same as the acid hydrolysis method proposed by Chinese CN101205256A patent

"Control of Relative Molecular Mass of Enzymatic Synthesis of Dextran" published in Volume 24, No. 10 of "Fine Chemical Industry" in October 2007 proposed adding dextranase during the synthesis of dextran with dextran sucrase produced by Leuconostoc membranaceus Degrade the generated polymer dextran, but the degradation time of this method is longer, which is 24 hours, and the weight average molecular weight of the obtained dextran product is relatively large, reaching 1.0×105-2.0×104.

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