阅读说明：本技术 一种d-丙氨酸的制备方法 (Preparation method of D-alanine ) 是由 林金新 郭小雷 黄平 于 2019-10-09 设计创作，主要内容包括：本发明涉及氨基酸技术领域,且公开了一种D-丙氨酸的制备方法。包括采用以下重量份数配比的原料：乙醛4-5份、氰化钠3-4份、氯化铵1-2份、氨水2-3份、硫酸2-3份、碱性水15-20份、米曲氨基酰化酶3-5份以及修饰试剂5-7份,修饰试剂选用烷基化试剂或双功能基团试剂中的一种,烷基化试剂是一种重要的巯基修饰试剂,通过修饰提高酶的稳定性,提高产率,适用于大规模工业化分离。(The invention relates to the technical field of amino acid and discloses a preparation method of D-alanine. The formula comprises the following raw materials in parts by weight: 4-5 parts of acetaldehyde, 3-4 parts of sodium cyanide, 1-2 parts of ammonium chloride, 2-3 parts of ammonia water, 2-3 parts of sulfuric acid, 15-20 parts of alkaline water, 3-5 parts of aspergillus aminoacylase and 5-7 parts of a modification reagent, wherein the modification reagent is one of an alkylation reagent or a bifunctional group reagent, the alkylation reagent is an important sulfydryl modification reagent, the stability of the enzyme is improved through modification, the yield is improved, and the method is suitable for large-scale industrial separation.)

1. The preparation method of the D-amino acid is characterized by adopting the following raw materials in parts by weight: 4-5 parts of acetaldehyde, 3-4 parts of sodium cyanide, 1-2 parts of ammonium chloride, 2-3 parts of ammonia water, 2-3 parts of sulfuric acid, 15-20 parts of alkaline water, 3-5 parts of aspergillus aminoacylase and 5-7 parts of a modifying reagent;

the method comprises the following steps:

(1) putting sulfuric acid and sodium cyanide into a sealed container to react for twenty-five to thirty-five minutes, then putting the sealed container into a five-ten-DEG C environment to condense for five-twenty minutes, and putting ammonium chloride into the sealed container to obtain a hydrocyanic acid product;

(2) putting acetaldehyde into a sealed container to react for ten to twenty minutes at the temperature of twenty to forty ℃, reacting the acetaldehyde with hydrocyanic acid to generate cyanohydrin, putting ammonia water into the sealed container to react for ten to twenty minutes, reacting the cyanohydrin with the ammonia water to generate aminonitrile, putting the aminonitrile into a container filled with alkaline water to react for fifteen to twenty minutes, wherein the pH value of the alkaline water is eight to ten, and hydrolyzing to generate sodium aminopropionate;

(3) under the environment that the temperature is stable to twenty to forty ℃, the aspergillus aminoacylase is put into a modification reagent for molecular modification, the modification time is fifty minutes to one hour and twenty minutes, and the modification reagent is one of an alkylation reagent or a bifunctional group reagent;

(4) adding the reagent generated in the step (3) into a sodium aminopropionate solution, stirring and reacting for twenty to thirty minutes in an environment with the temperature of thirty to forty ℃, separating L-alanine and acylated-D-alanine from the enzymatic hydrolysate by an ion exchange resin treatment method, and finally hydrolyzing the acylated-D-alanine to obtain the D-alanine.

2. The method of claim 1, wherein: the ammonium chloride is prepared by a recrystallization method.

3. The method of claim 1, wherein: the ammonia water is a synthetic liquid-phase product ammonia prepared by a danish toprim process.

4. The method of claim 1, wherein: the sulfuric acid is concentrated sulfuric acid with the mass fraction of ninety-eight points three.

5. The method of claim 1, wherein: the modification reagent is Br-CH₂CH₃N-butanol, glutaraldehyde, or PEG.

Technical Field

The invention relates to the technical field of amino acid, in particular to a preparation method of D-alanine.

Background

Amino acids are compounds in which the hydrogen atom on the carbon atom of a carboxylic acid is replaced by an amino group, and they can play the following roles in the human body through metabolism: firstly, synthesizing tissue protein; ② changing into ammonia-containing substances such as acid, hormone, antibody, creatine and the like; ③ to carbohydrate and fat; and oxidizing the carbon dioxide, the water and the urea to generate energy.

The existing natural amino acids are all L-amino acids, the molecular formulas of the D-amino acids and the L-amino acids are the same, but the spatial structures are just opposite, the D-alanine is an amino acid with special functions, the additional value is high, the D-alanine is a D-type amino acid with multiple purposes, and the mass production of the D-alanine is of great significance.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a preparation method of D-alanine, which has the advantages of suitability for mass production of D-alanine and the like and solves the problem of difficulty in the preparation method of mass production of D-alanine.

In order to realize the purpose of mass production of D-alanine, the invention provides the following technical scheme: a preparation method of D-amino acid adopts the following raw materials in parts by weight: 4-5 parts of acetaldehyde, 3-4 parts of sodium cyanide, 1-2 parts of ammonium chloride, 2-3 parts of ammonia water, 2-3 parts of sulfuric acid, 15-20 parts of alkaline water, 3-5 parts of aspergillus aminoacylase and 5-7 parts of a modifying reagent.

A method for producing a D-amino acid, comprising the steps of:

(1) putting sulfuric acid and sodium cyanide into a sealed container to react for twenty-five to thirty-five minutes, then putting the sealed container into a five-ten-DEG C environment to condense for five-twenty minutes, and putting ammonium chloride into the sealed container to obtain a hydrocyanic acid product.

(2) In an environment with the temperature of twenty to forty ℃, acetaldehyde is put into a sealed container to react for ten to twenty minutes, the acetaldehyde reacts with hydrocyanic acid to generate cyanohydrin, then ammonia water is put into the sealed container to react for ten to twenty minutes, the cyanohydrin reacts with the ammonia water to generate aminonitrile, the aminonitrile is put into a container filled with alkaline water to react for fifteen to twenty minutes, the pH value of the alkaline water is eight to ten, and the hydrolysis is carried out to generate the sodium aminopropionate.

(3) In the environment that the temperature is stable to twenty to forty ℃, the aspergillus aminoacylase is put into a modification reagent for molecular modification, the modification time is fifty minutes to one hour and twenty minutes, and the modification reagent is one of an alkylation reagent or a bifunctional group reagent.

(4) Adding the reagent generated in the step (3) into a sodium aminopropionate solution, stirring and reacting for twenty to thirty minutes in an environment with the temperature of thirty to forty ℃, separating L-alanine and acylated-D-alanine from the enzymatic hydrolysate by an ion exchange resin treatment method, and finally hydrolyzing the acylated-D-alanine to obtain the D-alanine.

The storage of sodium cyanide is adding inclosed and providing abundant local air exhaust and comprehensive ventilation's environment under strictly, and the user need wear the electronic air supply filtration formula dustproof respirator of hood type when taking, wears formula adhesive tape gas defense clothing of dress formula, wears rubber gloves, avoids producing the dust. Avoid contact with oxidant and acid.

The ammonium chloride is prepared by a recrystallization method, crude ammonium chloride is added into a dissolver, steam is introduced for dissolution, filtration is carried out, filtrate is cooled for crystallization, centrifugal separation and drying are carried out, and industrial ammonium chloride finished products are prepared.

Preferably, the sulfuric acid is concentrated sulfuric acid with the mass fraction of ninety-eight-point-three.

Preferably, the alkaline water is purified water which is treated, pure and free of impurities.

The modification reagent is one of an alkylation reagent or a bifunctional group reagent, the alkylation reagent is an important sulfydryl modification reagent, a disulfide bond can be formed to stabilize the structure of the enzyme, and the stability of the enzyme is improved through modification. Bifunctional group reagents such as glutaraldehyde, PEG and the like covalently crosslink different peptide chain parts among enzyme protein molecules, between subunits or in the molecules, so that the molecular active structure can be reinforced, the stability of the enzyme can be improved, and the application range of the enzyme in a non-aqueous solvent is expanded.

Compared with the prior art, the invention provides a preparation method of D-alanine, which has the following beneficial effects:

1. the preparation method of D-alanine modifies enzyme molecules through modifying reagent, increases enzyme stability, increases production efficiency and stability of products, and is suitable for mass production of D-alanine.

2. According to the preparation method of the D-alanine, the aspergillus oryzae produced by the aspergillus oryzae is used to produce the aspergillus amino acylase, and the aspergillus amino acylase has the characteristics of simple extraction and purification process and low cost, and is suitable for large-scale industrial separation.

3. The preparation method of the D-alanine has the advantages of stable reaction conditions of the used chemical reaction, low pollution, high yield and low cost, and is suitable for large-scale production.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.