Method for preparing low molecular weight brown seaweed fucoidan sulfate

Abstract

The invention relates to a method for preparing low molecular weight brown seaweed fucoidan sulfate. The method comprises a step of oxidatively degrading brown seaweed sulfated polysaccharides by hydroxyl radical and a step of ultrafiltration membrane separation and purification, wherein raw sugar of the brown seaweed sulfated polysaccharide is used as a raw material, the hydroxyl radical generated by the reaction of copper ions and hydrogen peroxide is adopted to oxidatively degrade the raw sugar of the brown seaweed sulfated polysaccharide, and the membrane separation technology is combined in the method for preparing the low molecular weight fucoidan sulfate from the brown seaweeds. In the preparation process, the oxidizing speed is uniform, the reacting condition is mild, and the controllability and repeatability are good; the copper ions are removed by a chelating column after the oxidation reaction is finished, so the operation process is simple. Furthermore, the pH value is adjusted by adding little acid and alkali, so the salt content in the product is low, and can be completely removed by a 300Da ultrafiltration membrane in the ultrafiltration membrane separation and purification process. The ultrafiltration membrane can effectively separate and purify the brown seaweed fucoidan with different molecular weights along with high separating speed and large treatment amount. The method is suitable for industrial production.

Description

technical field [0001] The invention belongs to the field of polysaccharide preparation, and in particular relates to a preparation method of low molecular weight fucoidan sulfate ester. Background technique [0002] Fucoidan sulfate is a unique sulfated polysaccharide in the cell wall of brown algae. The crude fucoidan sulfate extracted from brown algae by acid extraction and hot water extraction is a heteropolysaccharide with a molecular weight of about 100kDa to 800kDa. The main constituent unit is 1,2-α-fucose, with a sulfate group on C4, and xylose, mannose, galactose, glucose and rhamnose on the sugar chain, and a small number of arabinose; its uronic acid Mainly glucuronic acid or mannuronic acid, some contain galacturonic acid. The results of the study found that fucoidan sulfate in brown algae such as Fucus, Fucus, Staghorn, Ascophyllum nodosum, and Kelp has significant physiological effects such as anti-thrombotic, anti-tumor, and anti-virus, and has anti-inflamma...

AI Technical Summary

Problems solved by technology

However, the molecular weight distribution of oligosaccharides obtained by acid hydrolysis of fucoidan sulfate is difficult to control, the yield is relatively low, and the composition of the obtained polysaccharides is uneven, the desulfurization phenomenon is relatively serious, and the desalination step is troublesome

The use of hydrogen peroxide to directly oxidize and degrade fucoidan sulfated polysaccharides requires adding a large amount of hydrogen peroxide as an oxidant at one time, so the reaction is violent, the reaction conditions and products are difficult to control, and the obtained polysaccharides have low sulfate and fucose content.

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