JPH0780822B2 - Method for separating and purifying amino acids - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for separating and purifying amino acids. More specifically, it relates to a method for separating and purifying amino acids using a resin having an amino group coordinated with a metal ion.

Amino acids are used in a wide range of fields such as food, feed, pharmaceuticals, cosmetics, and industry.

<Prior Art> Amino acids are produced by any of a fermentation method, a synthetic method, and an extraction method, and then by a method of separating and purifying them from by-products or raw materials.

Separation and purification of a target amino acid and a by-product or a raw material are generally carried out by a crystallization method utilizing a difference in solubility.

However, amino acids have both an amino group and a carboxyl group in the molecule, form intramolecular salts, intermolecular salts, etc., and have similar solubilities, etc., so it is difficult to obtain highly pure amino acids. Purification is performed by complicated operations such as repeated crystallization methods.

In the case of amino acids such as leucine and isoleucine, which are structural isomers, which have almost the same solubility and cannot be separated by the crystallization method, a third component such as β-naphthalenesulfonic acid is added to form a salt of the third component of the amino acid. To form a pure crystal (Fine Chemical, 1982 March 3).
A complicated method such as the 15th of the month, p. 10) is used.

<Problems to be solved by the invention> Repetition of crystallization that is generally performed in the separation and purification step of amino acid production, and particularly separation and purification of amino acids which are inseparable by ordinary crystallization means such as leucine and isoleucine. Since it is processed by a very complicated method as described above, it has drawbacks such as a long manufacturing time, a large number of processing devices, and high construction costs and operating costs.

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

<Means for Solving the Problems> That is, the present invention is a method for separating and purifying amino acids, which comprises contacting a resin having a metal ion-coordinated amino group with an aqueous solution of an amino acid and then eluting it.

The resin having an amino group used in the present invention is not particularly limited as long as it is a resin capable of coordinating a metal ion and binding with a target amino acid via the metal ion.

Examples of the resin having such an amino group include amine reactive groups such as a nitrile group, a chloromethyl group, a sulfonyl chloride group, a carbonyl chloride group, an isocyanate group, an epoxy group, an aldehyde group, a halogen atom such as chlorine, bromine and iodine. To a polymer such as a phenol resin having polyethylene, polyethylene or polypropylene, or polyvinyl chloride (hereinafter referred to as a resin having an amine reactive group), ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, diethylenetriamine, triethylene. It is a resin having an alkylenepolyamino group obtained by reacting an alkylenepolyamine such as tetramine, tetraethylenepentamine, pentaethylenehexamine, and hexamethyleneheptamine.

The reaction between the resin having an amine-reactive group and the alkylene polyamine can be carried out by a known method, which will be described in detail below.

The reaction between the resin having an amine-reactive group and the alkylene polyamine is carried out in a self-solvent or in the presence of a solvent such as water, N, N-dimethylformamide, methyl alcohol, ethyl alcohol, dimethyl sulfoxide, toluene, hexane or heptane. To be done.

The reaction temperature is chloromethyl group, sulfonyl chloride group,
In the case of a resin having an amine reactive group which is highly reactive at a relatively low temperature such as a carbonyl chloride group, an isocyanate group, an epoxy group and an aldehyde group, it is preferably about 20 ° C or higher, preferably
Heat to 50-100 ° C. When the reaction temperature is lower than about 20 ° C., the reaction rate becomes slow and the reaction takes a long time, which is not preferable.

Further, in the case of a resin having an amine-reactive group which is relatively inferior in amine reactivity, such as a nitrile group, a halogen atom such as chlorine, bromine or iodine is directly bonded to the polymer main chain, about 10
Heating is performed at 0 to 170 ° C. When the reaction temperature is lower than about 100 ° C, the reaction rate of the amino compound with respect to the amine-reactive group becomes slow, and the reaction takes a long time.
When the temperature is higher than 0 ° C, the generated functional group is decomposed, which is not preferable.

The reaction is carried out at the above temperature for about 0.1 to 7 hours.

The optimum time within the range is appropriately determined depending on the reaction temperature, the concentration of the reaction solution, the solvent used, the resin having an amine reactive group, the type of alkylene polyamine, and the like. However, it is possible to react for a longer time.

The reaction is generally carried out at normal pressure, but it can be carried out under pressure.

Regarding the reaction ratio between the resin having an amine-reactive group and the alkylene polyamine, about 0.5 mol or more of the alkylene polyamine is used with respect to 1 mol of the amine-reactive group in the resin. The use of more alkylene polyamine than required complicates the recovery treatment operation after the reaction, and the alkylene polyamine used for the resin having an amine-reactive group is about 0.5.
When the amount is less than the molar amount, the substitution of the alkylene polyamine is reduced, the metal ion coordinating ability of the obtained resin having an amino group is decreased, and the binding amount of the amino acid to be purified bound through the metal ion is decreased to decrease Since the amount of separated and purified amino acids is reduced, preferably, the alkylene polyamine is about 0.5 to 3 with respect to 1 mol of the amine-reactive group in the resin.
Used in moles.

The resin having an alkylenepolyamino group produced as described above can be used as it is or after washing and drying to coordinate a metal ion to be used for separation and purification of amino acids. Alternatively, it can be used after being treated with an acid and coordinated with a metal ion.

The metal ion to be coordinated to the resin having an alkylenepolyamino group is not particularly limited as long as it is a metal capable of coordinating an amino acid for the purpose of separation and purification in the state of being coordinated to the resin having an alkylenepolyamino group. However, transition metal ions are generally used.

In particular, iron, cobalt, nickel, copper, and zinc ions, which are the fourth periodic elements of the periodic table, are easy to remove metal ions leaked to the purified amino acid side in the manufacturing price and the separation and purification process,
Preferably used.

The method of coordinating the metal ion with the resin having an alkylene polyamino group is carried out by passing an aqueous solution in which the metal ion is dissolved in a column packed with a resin having an alkylene polyamino group in advance, or by adding an alkylene polyamino group to the aqueous solution of the metal ion. A method of introducing a resin having a resin and contacting it with stirring for a predetermined time is adopted.

The amount of metal ions coordinated to the resin having an alkylene polyamino group is not particularly limited, but since the amount of the amino acid separated and purified decreases when the amount of coordinated metal ions decreases, generally about 0.1 g per 1 kg of resin is used. A resin in which metal ions having a number of atoms or more and a saturated capacity are coordinated is used.

The contact conditions between the aqueous solution in which the metal ion is dissolved and the resin having an alkylene polyamino group differ depending on the type of metal ion, the concentration of the metal ion, the temperature, and the type and amount of the resin having an alkylene polyamino group. Is set. Generally, 0.01 to 0.5 mol / mol at room temperature with respect to the resin 1 having an alkylene polyamino group
A method of contacting an aqueous solution of a metal mineral salt having a concentration of 1 to 100 for 0.1 to 24 hours is adopted.

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

The amino acid aqueous solution is not particularly limited as long as it has an affinity with a resin having an alkylenepolyamino group coordinated with a metal ion and contains an amino acid or an impurity compound having a different affinity. Examples of such amino acids and impurity compounds include leucine, isoleucine, methionine, cystine, cysteine, tyrosine, valine, phenylalanine, alanine, tryptophan, proline, serine, lysine, aminobutyric acid, and the like, anthranilic acid, 2-hydroxy- 4-methyl-
Examples thereof include amino acid synthetic raw materials such as thiobutyric acid, 2-hydroxy-3-phenyl-propionic acid, starch, molasses, acetic acid, n-paraffin, and glucose.

The resin having an alkylenepolyamino group coordinated with a metal ion used in the present invention is used for separating and purifying L-leucine or L-isoleucine from a solution obtained by neutralizing an acid hydrolyzate such as casein, keratin and hemoglobin with an alkali. Particularly excellent effect is recognized. Such an effect could not be expected from the known art at all.

In carrying out contact treatment with a resin having an alkylenepolyamino group coordinated with a metal ion and an amino acid aqueous solution,
The pH of the aqueous amino acid solution is preferably in the range of about 2 to 12 in order to prevent the affinity of the amino acid for the purpose of separation and purification from the resin having an amino group from being lowered. When the pH of the amino acid aqueous solution is less than about 2 or 12 or more, the affinity of the amino acid for the purpose of separation and purification with the resin decreases, and the purification efficiency decreases, which is not preferable.

The method of contacting the resin having a metal ion-coordinated alkylenepolyamino group with the amino acid aqueous solution is not particularly limited, and for example, a method of passing the amino acid aqueous solution into the column packed with the resin, into the amino acid aqueous solution. A method in which the resin is dipped and then separated by filtration is adopted.

In general, a method is used in which a resin having good operability is filled in a column and an amino acid aqueous solution is passed through.

The contact temperature between the resin having an alkylenepolyamino group coordinated with a metal ion and the amino acid aqueous solution is not particularly limited, and is usually about 0 to 100 ° C.

Moreover, the contact time is not particularly limited.

The amount of the resin, the contact temperature, the contact time, and the like to be used with respect to the amino acid aqueous solution are appropriately set by conducting preliminary experiments.

After the resin having an alkylenepolyamino group coordinated with a metal ion is subjected to a contact treatment with an aqueous solution of an amino acid by the above method, the amino acid for the purpose of separation and purification is separated from other amino acids or impurities. For this separation, a method by chromatographic separation utilizing the difference in affinity between each amino acid and the resin having an alkylenepolyamino group coordinated with a metal ion is used. The type and amount of the separating eluent for performing the chromatographic separation differ depending on the type of the resin having an alkylenepolyamino group in which each amino acid and a metal ion are coordinated, the amount of the amino acid coordinated in the resin, etc. Set by.

As the separation eluent, it is possible to use a developing solution used in known high performance liquid chromatography,
From the viewpoint of easy recovery of amino acids from the developing solution, a method using water, aqueous ammonia, mineral acid, an aqueous solution of caustic alkali metal, caustic alkaline earth metal alone or in combination is preferably used.

The eluate obtained by separating and purifying the amino acid for separation and purification from other amino acids and the like is then used as it is, or after further repeated purification treatment, by utilizing the solubility difference depending on pH, or by concentration precipitation treatment, and drying, etc. A purified amino acid can be obtained by a known method.

The resin after separation and elution of amino acids can be used as it is, or after re-coordinating a metal ion as necessary, and then repeatedly used for separation and purification of an amino acid aqueous solution.

<Effects of the Invention> Since a highly pure amino acid can be obtained very easily by the method of bringing an amino acid aqueous solution into contact with a resin having a metal ion-coordinated alkylenepolyamino group of the present invention and then eluting it, its value is Extremely large.

<Examples> Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 To 64 g of an acrylonitrile-divinylbenzene copolymer having a degree of crosslinking of 6 mol%, 206 g of diethylenetriamine which is an amino compound and 36 g of water were added, and the mixture was reacted at 120 to 130 ° C. for 4 hours,
Then, filtration and washing with water gave 231 g (undried) of a resin having an amino group. (Hereinafter, referred to as aminated resin A.) Next, 0.1 mol of CuSO ₄ and 0.5 mol of NH ₃ were added, and the resulting aminated resin A20 was added to 300 ml of an aqueous solution made up to 1 with water.
After contacting ml for 1 hour at room temperature, filtration and washing with water gave 1.2 g of an aminated resin A having copper ions coordinated. This resin was packed in a column, and a column filled with 20 ml of aminated resin A in which metal ions were not coordinated was connected in series below the column of copper ion-coordinated aminated resin A.

The column was filled with deionized exchanged water, then pH was 6.2 from the top of the column, and 1 L-leucine and 1 L-isoleucine each.
20 ml of 0 g / concentrated mixed aqueous solution for 30 minutes, then 200 ml of deionized water as a separating eluent for 2 hours, and then a second
Aqueous solution of 0.5 normal concentration of 200
When ml was allowed to flow for 2 hours, a separated eluate obtained by separating and purifying L-leucine and L-isoleucine as shown in FIG. 1 was obtained. The separated eluate was further concentrated under reduced pressure. As a result, 0.21 g of L-isoleucine having a purity of 93% was obtained from the eluate of the deionized water separation (yield of L-isoleucine was 98%) and the L-isoleucine having a purity of 99% was extracted from the eluate of the aqueous ammonia separation. -Leucine 0.19
g (L-leucine yield 94%) was obtained.

Examples 2 to 5 Separation and purification of L-leucine and L-isoleucine were carried out in the same manner as in Example 1 except that the kind of metal ion coordinated to the aminated resin A used in Example 1 and the coordination amount were changed. I went. The results are shown in Table 1.

Comparative Example 1 A mixed aqueous solution of L-leucine and L-isoleucine was separated and purified in the same manner as in Example 1 except that the aminated resin A used in Example 1 in which metal ions were not coordinated was used. .

Both L-leucine and L-isoleucine were all eluted outside the resin tower system when 50 ml of deionized exchanged water was passed as a separation eluent, and each amino acid could not be separated at all.

Examples 6 to 9 Production of an aminated resin, coordination of copper ions and L-leucine and L-isoleucine were prepared in the same manner as in Example 1 except that the type and amount of the amino compound used in Example 1 were changed. It was separated and purified. The results are shown in Table 2.

Examples 10 and 11 (Amination resin F) 940 g of phenol, 110 g of resorcin and 1200 g of 25% by weight formalin were added, and prepolymerization was carried out at 80 ° C. for 4 hours.
1440 g of triethylenetetramine and 1000 g of 36% by weight hydrochloric acid
2400 g of 25% by weight formalin was added, and the reaction was further performed at 80 ° C. for 2 hours. After the reaction, filter and wash with water, then at 80 ℃
The dehydration condensation reaction was performed under reduced pressure. After the reaction, crush the resin
1050 g of resin having a particle size of 10-60 mesh was obtained.

(Amination resin G) 1250 g of a methyl methacrylate-divinylbenzene copolymer having a degree of crosslinking of 10 mol% and 4120 g of diethylenetriamine, which is an amino compound, were reacted in an autoclave at 170 ° C. for 7 hours to carry out dehydration condensation reaction. An undried resin was obtained.

L-leucine and L-isoleucine were separated and purified in the same manner as in Example 1 except that the aminated resin A was replaced with the aminated resins F and G. The results are shown in Table 3.

Examples 12 to 15 and Comparative Example 2 Casein was added to the aqueous amino acid solutions of Examples 1 to 11 at 5 g / L.
-Leucine was changed to a caustic aqueous solution having a pH of 9 at a concentration of 5 g / concentration, and the metal ion-coordinated amination resin was replaced with those of Examples 1, 2, 3,
Separation and purification were performed in the same manner as in Example 1 except that the aminated resin A in which the metal ion used in 6 and Comparative Example 1 was not coordinated was used. The results are shown in Table 4.

[Brief description of drawings]

FIG. 1 is a diagram showing the concentration of amino acids in the separated eluate in Example 1 against the amount of separated eluate. The horizontal axis is the amount of separated eluate, the vertical axis is the amino acid concentration, Is the L-isoleucine concentration, Represents the L-leucine concentration.

Claims (1)

[Claims] 1. A resin having an alkylene polyamino group in which ions of a metal selected from copper, cobalt, nickel, iron and zinc are arranged, and an aqueous solution of one or both amino acids of L-leucine and L-isoleucine. A method for separating and purifying amino acids, which comprises contacting and then eluting.