JPH0558972A - Method for separating and purifying amino acids - Google Patents

Abstract

(57) [Abstract] [Purpose] A method for separating and purifying amino acids by contacting a resin having metal ions coordinated with an aqueous solution of amino acid to adsorb the amino acid on the resin and then eluting the adsorbed amino acid. Increase the purity of the purified amino acids. [Composition] Contact of a resin having metal ions coordinated with an aqueous solution of an amino acid is carried out by a contact filtration adsorption method. The resin thus adsorbing the amino acid is then contacted with an eluent such as aqueous ammonia to elute the adsorbed amino acid. [Effect] The target amino acid can be separated and purified with high purity.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for separating and purifying amino acids, and more particularly to a method for separating and purifying amino acids using a resin having a functional group coordinated with a metal ion.

[0002]

Amino acids are used for foods, feeds, pharmaceuticals,
It is used in a wide range of fields such as cosmetics and industrial products.

Amino acids are produced by any of the fermentation method, the synthetic method and the extraction method, and usually, by-products and raw materials contained as impurities are then separated and purified. As a method of separating and purifying a target amino acid from by-products and raw materials such as other amino acids, a crystallization method utilizing a difference in solubility is generally adopted. Since the solubility of amino acids in general organic solvents is low, the crystallization method using an aqueous solution is usually used. In this case, the solubilities of multiple amino acids present in the aqueous solution are often similar, so in order to separate the target amino acid from other amino acids to obtain a highly pure product, the crystallization method is repeated. It requires complicated operations.

Particularly, in the case of amino acids which are structural isomers such as leucine and isoleucine, the two cannot be separated by a usual crystallization method. Therefore, for example, as described in "Fine Chemical", March 15, 1982, page 10, β-naphthalenesulfonic acid or 2-bromo-5
-A complicated method such as adding a third component such as toluenesulfonic acid to form an amino acid as a salt with the third component and separating them by utilizing the difference in their solubilities must be used.

Thus, in the conventional amino acid production process,
Separation and purification of amino acids which cannot be separated by ordinary crystallization means, such as repeated crystallization or particularly leucine and isoleucine, require the extremely complicated treatment as described above. Therefore, it has a drawback that the manufacturing time is long, a large number of processing devices are required, and construction cost and operating cost are large.

As a purification method by mutual separation of amino acids, which improves the above-mentioned drawbacks of the conventional method, the present inventors have previously had an aminocarboxylic acid type or aminophosphonic acid type chelating functional group coordinated with a metal ion. Contact the resin with the amino acid aqueous solution to adsorb the amino acid on the resin,
Then, a method for eluting the adsorbed amino acid was found and a patent application was filed (Japanese Patent Laid-Open No. 1-258652). The method disclosed in this publication exerts an unprecedented effect in separation and purification of amino acids having similar properties. However, it is not always sufficiently satisfactory in terms of separating and recovering the target amino acid with high purity. In particular, in the crystallization in the next step, the impurity content is preferably 1% or less in order to obtain an amino acid having a purity of almost 100% by the one-step treatment.

[0007]

In view of such circumstances, the inventors of the present invention have conducted intensive studies to find a method for efficiently separating and purifying amino acids of higher purity, and as a result, completed the present invention.

[0008]

Means for Solving the Problems In the present invention, when a resin having metal ions coordinated is brought into contact with an amino acid aqueous solution, the amino acid to be separated and purified is adsorbed on the resin by the contact filtration adsorption method, and then adsorbed. The present invention provides a method for separating and purifying amino acids by eluting the amino acids.

The resin used in the present invention has a functional group that coordinates with a metal ion such as a carboxylic acid group, a sulfonic acid group, a phosphonic acid group and an amino group, and a metal ion is coordinated thereto. Any resin that coordinates such a metal ion and that adsorbs the amino acid to be separated can be used in the present invention. As the resin having a functional group that coordinates with a metal ion, a commercially available ion exchange resin or chelate resin can be used, or it can be produced by a known method. Therefore, the substrate, shape, manufacturing method, etc. of the resin used in the present invention are not particularly limited. Preferred specific examples of the resin having a functional group that coordinates with a metal ion that can be used in the present invention are shown below.

(1) Carboxylic acid group-type chelating resin: Amino resin or polyamino resin, such as monochloroacetic acid, monobromoacetic acid, monochloropropionic acid, monobromopropionic acid, or an alkali metal salt or alkaline earth metal salt thereof. A resin obtained by reacting a halogenated alkylcarboxylic acid compound. The amino resin used here has a primary or secondary amino group, and includes, for example, a nitrile group, a chloromethyl group, a sulfonyl chloride group, an isocyanate group, a carbonyl chloride group, an epoxy group, an aldehyde group, or chlorine or bromine. It can be obtained by reacting a polymer having an amine reactive group such as a halogen atom such as iodine with ammonia, methylamine or ethylamine. The polyamino resin is a resin having two or more primary or secondary amino groups in the molecule. For example, a polymer having an amine reactive group as described above is added to ethylenediamine, trimethylenediamine, tetramethylenediamine. , Hexamethylenediamine, octamethylenediamine, nonamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hydrazine, guanidine and the like.

Acrylic acid, methacrylic acid, acetylenedicarboxylic acid, maleic acid, alkali metal salts or alkaline earth metal salts of these acids, or methyl ester can be added to the above amino resin or polyamino resin.
A resin obtained by reacting an ethyl ester or the like (hereinafter referred to as an acrylic acid compound), and when an ester is used, followed by hydrolysis.

Obtained by reacting the above-mentioned polymer having an amine-reactive group with an amino acid compound such as glycine, alanine, β-alanine, iminodiacetic acid, iminodipropionic acid, ethylenediaminediacetic acid, and ethylenediaminetriacetic acid. resin.

Commercially available Sumichelate MC-30, MC-75,
MC-76, MC-77, MC-78, Sumisepare AS-12, AS-13,
AS-23 [Made by Sumitomo Chemical Co., Ltd.], Duolite C-
464, C-466 [Made by Duolite International Co., Ltd.], Diaion WK-10, WK-20, CR-10 [Made by Mitsubishi Kasei Co., Ltd.], Uniselec UR-10, UR-20, UR-30,
Chelating resins such as UR-40 and UR-50 (all manufactured by Unitika Ltd.).

(2) Phosphonic acid group-type chelate resin: In addition to the above-mentioned amino resin or polyamino resin,
An alkyl phosphorylating agent such as chloromethyl phosphoric acid or chloroethyl phosphoric acid, or an alkylene agent such as formaldehyde, and a phosphorylating agent such as phosphorus trichloride, phosphorous acid, methyl phosphite or ethyl phosphite under an acidic catalyst such as hydrochloric acid or sulfuric acid. Resin obtained by reacting with.

Commercially available Sumichelate MC-95, Sumisepare AS-14, AS-24 (all manufactured by Sumitomo Chemical Co., Ltd.), Duolite C-467 (manufactured by Duolite International), Uniselec UR-3300 (Unitika (stock) ) Made] chelate resin.

(3) Resin having sulfonic acid group: commercially available Sumikaion KC-470 (manufactured by Sumitomo Chemical Co., Ltd.), Duolite C-20, C-26 (manufactured by Duolite International), Diaion SK1B [Mitsubishi Kasei Co., Ltd.
Made] resin.

In the present invention, in particular, a resin obtained by reacting a polyamino resin with a halogenated alkylcarboxylic acid compound, an acrylic acid compound, an amino acid compound, an alkyl phosphorylating agent, or an alkylating agent and a phosphorylating agent,
That is, a so-called polyaminocarboxylic acid type or polyaminophosphonic acid type chelate resin having a carboxylic acid group or a phosphonic acid group bonded to a polymer main chain through a polyalkylene polyamino group in a side chain is preferably used.
When such a polyaminocarboxylic acid type or polyaminophosphonic acid type chelate resin is used, leakage of metal ions coordinated to the functional group to the amino acid after separation and purification is small, and a high separation and purification effect is obtained. Be done. Among them, a chelate resin in which the above polyaminocarboxylic acid group or polyaminophosphonic acid group is bonded to an acrylic substrate is particularly preferably used from the viewpoint of separation and purification efficiency.

The metal ion to be coordinated with the resin may be any one as long as the amino acid for the purpose of separation and purification can be coordinated in the state where the metal ion is coordinated with the resin, and is not particularly limited. However, transition metal ions are generally preferred. In particular, iron, which is the fourth element of the periodic table,
Ions of cobalt, nickel, copper, and zinc are preferably used in terms of production cost and a small amount of metal leaked to the purified amino acid side in the separation and purification step. Of these, copper ions and cobalt ions are more preferable.

The method of coordinating the metal ion with the resin having the functional group is as follows: An aqueous solution in which the metal ion is dissolved is passed through a column packed with the resin in advance, or the resin is added to the aqueous solution of the metal ion. Then, a method of contacting with stirring for a predetermined time can be adopted.

The amount of metal ions coordinated to the resin having the above functional group is not particularly limited, but the amount of coordinating metal ions decreases, the amount of amino acid separation and purification processing decreases, so generally 1 kg of resin is used. It is preferred to coordinate up to about 0.1 gram atom per atom of metal ion up to the saturation capacity.

The contact conditions between the aqueous solution in which the metal ion is dissolved and the resin having the functional group are different depending on the kind and concentration of the metal ion, the contact temperature, and the kind and amount of the resin having the functional group. It is decided by doing. In general, 1 to 100 liters of an aqueous metal mineral acid salt solution having a concentration of about 0.01 to 0.5 mol / L is added to 0.1 to 2 at room temperature per liter of the resin having the functional group.
A method of contacting for 4 hours is adopted.

The resin having the functional group coordinated with the metal ion in this manner is brought into contact with the amino acid aqueous solution to be separated and purified as it is or after washing with water as necessary.

The aqueous solution of an amino acid to be treated in the present invention contains an amino acid having an affinity for a resin coordinated with a metal ion, and another amino acid having an affinity different from the affinity of the amino acid for the resin and / or Any substance containing an impurity compound may be used. Examples of such amino acids and impurity compounds include amino acids such as methionine, cystine, cysteine, tyrosine, valine, phenylalanine, alanine, tryptophan, proline, histidine, serine, lysine, aminobutyric acid, leucine and isoleucine, and anthranilic acid, 2- Hydroxy-4-methyl-thiobutyric acid, 2-hydroxy-3-
Examples include amino acid synthesis raw materials such as phenyl-propionic acid. An aqueous solution containing an amino acid to be separated and purified selected from the above-mentioned amino acids and further containing another amino acid and / or an impurity compound is to be treated.

In the method of the present invention, the content of the amino acid to be separated and purified is particularly equimolar or more, more preferably 1.2 times or more, and further preferably 2 times the molar amount of other impurity amino acids and / or impurity compounds. Excellent effects are obtained when the above aqueous solution is treated. Especially, it is excellent in the separation and purification of histidine, serine, lysine, phenylalanine, methionine or leucine. Particularly, an excellent effect is recognized in the separation and purification of leucine containing, as impurities, isoleucine or methionine produced by precipitation by neutralizing acid hydrolysates such as casein, keratin and hemoglobin with an alkali.

In contacting the resin having metal ions coordinated with the amino acid aqueous solution according to the present invention, the pH of the amino acid aqueous solution is preferably in the range of about 2 to about 12, and particularly pH.
More preferably, it is carried out in the range of about 3 to about 10. If the pH of the amino acid aqueous solution deviates from this range and becomes less than about 2 or more than about 12, the purification efficiency is lowered, which is not preferable.

The contact temperature between the amino acid aqueous solution and the resin is not particularly limited, and it is carried out at any temperature between about 0 ° C and about 100 ° C. The contact time is also not particularly limited, and amino acids are sufficiently adsorbed even when contacted for a short time. The preferable contact time and contact temperature can be set by appropriately performing preliminary experiments depending on the type and concentration of amino acid, the type and amount of resin, and the like. Further, the amount of the resin having the functional group coordinated with the metal ion can also be set by appropriately performing a preliminary experiment.

The contact between the resin having a functional group coordinated with a metal ion and the aqueous amino acid solution according to the present invention is carried out by a catalytic filtration adsorption method. At this time, the resin may be added to the amino acid aqueous solution, or the amino acid aqueous solution may be added to the resin, but usually, the resin is added to the amino acid aqueous solution and immersed, and the resin is stirred after stirring if necessary. A method of separating by filtration is adopted. By adopting the method of catalytically adsorbing the resin to the aqueous amino acid solution in this manner,
For example, compared to the case where a resin is packed in a column and passed through, a ratio of adsorbing an impurity amino acid other than the amino acid to be separated and purified or another impurity compound is small,
Therefore, the target amino acid can be separated and purified with high purity.

Separation of the resin and the amino acid aqueous solution after contact is
It can be carried out by a known method such as centrifugal filtration or pressure filtration, but an apparatus having a filter in the adsorption tank is preferable because the equipment scale can be reduced. As such a device, for example,
Examples include Rosenmund filter and Neutrex (manufactured by Swiss Rosenmund).

In the method of the present invention, the resin having the functional group to which a metal ion is coordinated and the amino acid aqueous solution are subjected to catalytic filtration and adsorption treatment to adsorb the amino acid for the purpose of separation and purification onto the resin. The resin is washed as it is, or after washing with water as necessary, the adsorbed amino acid is eluted with a separating eluent. Examples of such a separating and eluting agent include water, ammonia water, and
Aqueous solutions of mineral acids, alkali metal hydroxides or alkaline earth metal hydroxides are preferably used, and these can be used alone or in combination.

The aqueous solution in which the amino acid is eluted in this manner can be subjected to a known method such as concentration and precipitation treatment and drying to obtain a purified amino acid. Further, the resin after elution of the amino acid can be used as it is, or after re-coordinating a metal ion as necessary, it can be repeatedly used again for separation and purification of the amino acid aqueous solution.

[0031]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the following examples, the purity of the amino acid to be purified is represented by the weight-based value calculated according to the following formula.

Purity (%) of target amino acid to be purified = (weight of target amino acid / weight of all amino acids including target amino acid)
× 100

Example 1 A commercially available chelating resin having a carboxylic acid group, Sumisepare AS-13 (manufactured by Sumitomo Chemical Co., Ltd.) was prepared. On the other hand, 0.05 mol of copper sulfate and 0.5 mol of ammonia were added to 1 liter of water to prepare a copper sulfate aqueous solution. 250 ml of this copper sulfate aqueous solution was contacted with 10 ml of the above resin at room temperature for 1 hour, then filtered and washed with water to obtain chelate resin A having 0.35 g of copper ions coordinated. 150 ml of an aqueous solution of an amino acid (leucine purity 98.0%) containing 1.5 g of leucine and 0.03 g of isoleucine was added to this chelate resin A.
To 10 minutes, stirred, filtered, and washed with water. 150 ml of 1N ammonia water was added to the resin thus adsorbing the amino acid, and the resin was filtered after stirring for 1 hour. The amino acid content of the obtained ammonia eluate was 0.38 g of leucine and 0.002 g of isoleucine, and the leucine purity was 99.5%.

The leucine purity in this example is calculated by the following equation as described above, and the amino acid purity in other examples is also calculated by the same standard.

Leucine purity (%) = {leucine content /
(Leucine content + isoleucine content)} × 100

Example 2 10 ml of Sumicepare AS-12 (manufactured by Sumitomo Chemical Co., Ltd.), which is a commercially available chelating resin having a carboxylic acid group, was used.
This is the same copper sulfate aqueous solution 250 as that used in Example 1.
chelate resin B in which 0.5 g of copper ion is coordinated by contacting with 1 ml at room temperature for 1 hour, filtering and washing with water.
Got When this resin B was stirred and contacted with the same amino acid aqueous solution as used in Example 1 and the same treatment as in Example 1 was carried out, the amino acid content of the ammonia aqueous solution after elution was leucine 0.25 g, and isoleucine Was not detected.

Example 3 Sumisepare AS-14 (manufactured by Sumitomo Chemical Co., Ltd.), which is a commercially available chelating resin having a phosphonic acid group, was used in an amount of 10 ml.
This is the same copper sulfate aqueous solution 250 as that used in Example 1.
chelate resin C with 0.31 g of copper ion coordinated by contacting with 1 ml at room temperature for 1 hour, then filtering and washing with water.
Got This resin C was stirred and contacted with the same amino acid aqueous solution as used in Example 1 and treated in the same manner as in Example 1. The amino acid content of the ammonia aqueous solution after elution was 0.5 g of leucine and 0.0023 g of isoleucine. And the leucine purity was 99.5%.

Comparative Example 1 10 ml of chelating resin A coordinated with copper ions by the same treatment as in the first half of Example 1 was packed in a 10 mmφ glass column, and leucine (1.5 g) and isoleucine were charged in this column.
150 ml of amino acid aqueous solution containing 0.03 g, space velocity 5 hr
^-1 was passed. Then, it was washed with 100 ml of ion-exchanged water, and 150 ml of 1N ammonia water was passed through to elute the adsorbed amino acid. The amino acid content of the ammonia effluent obtained was 0.65 g of leucine and 0.0075 of isoleucine.
and the leucine purity was 98.9%.

Comparative Examples 2 to 3 Using the chelate resins B and C obtained by treating in the same manner as in the first half of Example 2 and the first half of Example 3, the same liquid passing experiment as in Comparative Example 1 was conducted. The results are shown in Table 1.

[0040]

[Table 1]

Examples 4 to 6 Chelating resins A, B and C obtained by treating in the same manner as in the first half of Examples 1, 2 and 3 were used, each containing an amino acid containing 0.6 g of cystine and 0.2 g of methionine. Washing with water and elution were carried out in the same manner as in Example 1 except that 200 ml of an aqueous solution (purity of cystine 75%) was added. The results are shown in Table 2.

[0042]

[Table 2]

Comparative Examples 4 to 6 Chelating resins A, B and C obtained by treating in the same manner as in the first half of Examples 1, 2 and 3 were used, and Examples 4 to 6 were used.
Column flow was performed in the same manner as in Comparative Examples 1 to 3 except that the same amino acid aqueous solution as that used in 6 was used. The results are shown in Table 3.

[0044]

[Table 3]

Examples 7 to 9 Chelating resins A, B and C obtained by treating in the same manner as in the first half of Examples 1, 2 and 3 were used, each containing an aqueous amino acid solution containing 5 g of phenylalanine and 2 g of tryptophan ( Phenylalanine purity 71.4%) 200
Washing with water and elution were carried out in the same manner as in Example 1 except that the solution was added to the solution in ml. The results are shown in Table 4.

[0046]

[Table 4]

Comparative Examples 7 to 9 Using chelate resins A, B and C obtained by treating in the same manner as in the first half of Examples 1, 2 and 3, and Examples 7 to
Column passing was performed in the same manner as in Comparative Examples 1 to 3 except that the same amino acid aqueous solution as that used in 9 was used. The results are shown in Table 5.

[0048]

[Table 5]

[0049]

Industrial Applicability According to the method of the present invention, a highly pure amino acid can be easily obtained, so that its industrial value is extremely high.

Claims (6)

[Claims] 1. A resin to which a metal ion is coordinated and an aqueous solution containing impurities in addition to the amino acid to be purified are brought into contact by a contact filtration adsorption method to adsorb the target amino acid, and then adsorbed. A method for separating and purifying amino acids, which comprises eluting the amino acids. 2. The method according to claim 1, wherein the amount of the amino acid to be purified in the amino acid aqueous solution is at least twice the molar amount of impurities. 3. The method according to claim 1, wherein the resin having a metal ion coordinated therein is a chelate resin having an aminocarboxylic acid type or aminophosphonic acid type chelating functional group. 4. The functional group in the chelate resin is bound to the resin substrate via a polyalkylene polyamine.
The method described. 5. The method according to claim 1, wherein the metal ion is a copper ion or a cobalt ion. 6. The method according to any one of claims 1 to 5, wherein the catalytic filtration adsorption is carried out using an apparatus having an adsorption tank equipped with a filter.