Preparation method for selenomethionine

Abstract

The invention provides a preparation method for selenomethionine. The selenomethionine comprises L-selenomethionine, D-selenomethionine and DL-selenomethionine. The preparation method for the selenomethionine comprises the following steps: step 1, subjecting selenium powder, an alkali and hydrazine hydrate to a reaction; step 2, adding a bicarbonate; step 3, preparing methyl hydroselenide; and step 4, preparing the selenomethionine. The preparation method for the selenomethionine provided by the invention has the advantages of cheap and easily-available raw materials, mild reaction conditions,simple process steps, high product yield, low production cost, greenness, environmental protection, safety, high efficiency and applicability to industrial production.

Description

technical field [0001] The invention belongs to the field of selenomethionine, and in particular relates to a preparation method of selenomethionine. Background technique [0002] In 1982, my country's "Journal of Nutrition" publicly disclosed for the first time that 72% of my country's regions were selenium-deficient or low-selenium regions, and 2 / 3 of the population had insufficient selenium intake to varying degrees. Therefore, people have to adopt external selenium supplements to meet the needs of human body and animals for selenium. [0003] At present, selenium supplement products have two forms, inorganic and organic, and the selenium in the inorganic state is mainly composed of sodium selenite (Na 2 SeO 3 ) mainly. Inorganic selenium has many deficiencies, such as low utilization rate, high toxicity, and easy occurrence of poisoning. Organic selenium is mainly L-selenomethionine, which has high absorption rate, strong biological activity, high biological potency ...

AI Technical Summary

Problems solved by technology

At present, the synthesis of L-selenomethionine can be obtained by biological fermentation and chemical synthesis. The former mainly uses inorganic selenium sodium selenite as raw material. Through biological fermentation, inorganic selenium is converted into L-selenomethionine. The problems are: ① the selenium content of the product is very low, currently only 0.03%-0.1%; ② the shape and purity of the product are unstable, and the quality is not easy to be controlled; ③ the production process is complicated; ④ the production efficiency is low and the investment scale is large; Among them, the conversion rate of inorganic selenium is low, and most of the unconverted inorganic selenium is discharged in the form of wastewater, causing serious pollution to the environment

Highly toxic sodium cyanide is required, and the process is complicated

This method has long reaction steps, limited source of raw material methylselenol, and high difficulty in preparation, low boiling point, volatile and foul smell, and uses extremely toxic sodium cyanide at the same time, which poses huge risks in terms of safety, environmental protection and occupational health.

[0006] (3) Aminobutyrolactone method (Song Lianqing et al. Synthesis of selenomethionine. Journal of Zhengzhou Grain Institute, 1999,20(4):62~64): starting from γ-butyrolactone respectively, after bromination and amination To prepare α-amino-γ-butyrolactone, the selenium powder is reduced by hydrazine hydrate or sodium borohydride, methylated by methyl iodide or dimethyl sulfate to prepare dimethyl diselenide, and then dimethyl diselenide is passed through Reduction, ring opening with α-amino-γ-butyrolactone, hydrolysis, acidification and other 9 steps to obtain the target product, the total yield is about 33%. This process uses relatively cheap γ-butyrolactone as the starting material , what is obtained is a mixture of D and L-selenomethionine, which is difficult to separate, and this synthetic route needs to add highly toxic liquid bromine at a temperature close to the boiling point of bromine, which is difficult to operate and requires high equipment

[0007] (4) Methyllithium method (T.Koch, O.Buchardt, Synthesis, Synthesis, 1993, 1993(11): 1065-1067): the target compound is obtained from methionine through 7 steps, and the total yield is less than 30 %, the chemical reagents methyl lithium and tributoxy boron with extremely low safety are used in the process, and the price is high, the reaction needs to be in harsh anhydrous and oxygen-free conditions, the requirements for equipment and operation are very high, and it is difficult to achieve large-scale Production

[0011] 1. There are no industrial products for the main raw materials, the source is limited, and the price is expensive and the production cost is high;

[0012] 2. The reaction conditions are harsh and the synthesis route is complicated, so it is not easy to realize industrialization;

[0013] 3. Reaction equipment requires high requirements and large investment;

[0014] 4. The safety and occupational health risks of raw materials, intermediates or preparation processes are high;

[0015] 5. The environmental pollution in the production process is serious, and it is impossible to realize clean production

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