JPS5821905B2 - L - Amino Sanno Bunrihouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for separating monoamino acids contained in an optical resolution solution.

More specifically, by treating an aqueous solution obtained by asymmetric hydrolysis of α-(N-acyl)-DL-amino acids with a strongly acidic cation exchange resin divided into three parts, L-amino acids can be converted into α-amino acids. -(N-acyl)-D-amino acid and Na+.

This invention relates to a method for separating and collecting cations such as Can.

When performing optical resolution of DL-amino acids, it is well known that the N-acyl derivative is subjected to asymmetric hydrolysis by the action of acylase. Acylase is allowed to act either in its momme form or in a form adsorbed to a water-insoluble adsorbent, or acylase-producing microorganisms are adsorbed to a water-insoluble adsorbent or directly inoculated. It is implemented by methods etc.

The L-amino acid and α-(N-
Examples of methods for separating monoamino acids from mustard (acyl)-D-amino acids include methods that utilize differences in solubility in water or organic solvents, and methods that utilize differences in adsorption power to ion exchange resins. Concerning improvements in the exchange resin method.

In the conventional ion exchange resin method, it is common for cations such as Na+ and K10, which are involved in pH adjustment, to coexist in the optical separation solution, and these cations, along with L-amino acids, are As a result of being adsorbed to the cation exchange resin,
Depending on the type of eluent, for example, the elution rate may be low under the commonly used elution conditions of 2N-ammonia water, or when hydrochloric acid is used as the eluent, the purity of the L-amino acid obtained may be extremely reduced. It has its drawbacks.

As a result of intensive research to overcome these drawbacks, the present inventors have determined that only the adsorption band for cations such as Na and the adsorption band for L-amino acids in strongly acidic cation exchange resins can be selectively removed. It was discovered that it could be separated and collected, and the present invention was completed.

In the present invention, a first half part that is saturated with alkali metal ions and/or alkaline earth metal ions and/or heavy metal ions in the optical resolution liquid and a second half part that adsorbs the entire amount of L-amino acids are installed respectively. This is carried out by treating the optical separation solution with the same or different strongly acidic cation exchange resins connected in series.

Although the present invention uses a strongly acidic cation exchange resin in this way, it is not used in a single column system as in the past (the strongly acidic cation exchange resin is divided into three parts). , is characterized in that it is used in a column method in which both are connected in series.

Therefore, in the present invention, the column is combined with the metal ion adsorption section and the L-
It is important to divide the amino acid adsorption part into three parts,
The three parts of the strongly acidic ion exchange resin may be different or the same.

In the strongly acidic cation exchange resin used in the present invention, which consists of three parts, the first part contains alkali metal ions such as Na+ and K10 and/or alkaline earths such as Ca2 contained in the optical separation solution. A strongly acidic cation exchange resin with a capacity relative to the total amount of similar metal ions and/or heavy metal ions such as Co Replacement resin must be used.

According to the present invention, cations such as Na and the like coexisting in the optical resolution solution are intensively adsorbed in the first half, and L-amino acids only need to be eluted in the latter half, for example, 2
Even when eluted with N-ammonia water, the elution rate is high and the yield is improved, and even when eluted with hydrochloric acid, the yield is improved and very high purity monoamino acids are obtained, and they coexist in the optical resolution solution. The adverse effects of cations such as Na10 on elution of L-amino acids are significantly reduced.

In carrying out the present invention, the concentration of the optical resolution solution may be the usual substrate concentration for acylase, and the α-(N-acyl)-DL-amino acid concentration is suitably 0.05 to 0.5 M/A. It is.

In addition, if the adsorption rate of the optical resolution solution is maintained at a level that does not cause L-amino acids to be washed away from the latter half, L-amino acids and Na
There is no problem in separating from cations of the 10th order, usually 5v=o:
5 to 5 Hr' is preferable.

In addition, normal elution conditions such as 2N-ammonia water and 2N-hydrochloric acid can be applied to elute the latter part where L-amino acids are intensively adsorbed.
Since the negative effects of cations of the order of magnitude are alleviated, good results are obtained for purity and yield.

In terms of operation, the present invention also has the convenience of using an ion exchange resin in a tower system, and the optical resolution of amino acids can be carried out by immobilizing acylase or acylase-producing microorganisms on a water-insoluble adsorbent. The present invention can be particularly effectively used for the separation of monoamino acids in the optical separation solution when carried out using a column method.

The implementation of the present invention is also not limited to the use of three strongly acidic cation exchange resins connected in series in a permanently connected format; In this case, L-amino acids are all adsorbed together with metal ions in the first half, but L-amino acids are absorbed from the first half.
- As long as the amino acid does not flow out, the liquid can be used without necessarily passing through the latter part, and as a result, the operations of the first half and the latter part can be adjusted independently, which makes the present invention industrially advantageous. The value is extremely high.

The strongly acidic cation exchange resin used in the present invention may be any ordinary strongly acidic cation exchange resin having a sulfonic acid group, such as Amberlite IR-120B (trade name, manufactured by Rohm and Haas, USA), Mitsubishi Examples include Kasei Kogyo Co., Ltd.'s product name Diaion ■5KIB and DOWEX ■50W-X8.

Next, the present invention will be explained using Examples and Comparative Examples.

Example 1 H-type strongly acidic cation exchange resin, Diamond SK
IB 600ml (1.9meg/ml) and H-type strongly acidic cation exchange resin, Amberlite IR
Fill 400 ml (2.0 meg/ml) of 12OB into separate columns 1, and connect them in series in that order.

Then, adjust the pH to 7.0 with NaOH and add 0.2 M/
5.41 cL of an aqueous solution of 100% optical resolution of 7 concentrations of N-acetyl-DL-α-aminobutyric acid using immobilized acylase.
-α-aminobutyric acid 0.53 mol, Na + 1.22 mol)) was added at 1.0. Flow at a flow rate of ff/h.

After washing with 1 to 2 tons of pure water, the two units were disconnected, and 0.8 tons of 2N-hydrochloric acid was eluted from the latter column at a flow rate of 5 V = 1 (hr t), as shown below. L-α-aminobutyric acid hydrochloride was obtained with a yield of 96% and a purity of 98%.

Incidentally, when 5.4 t of the optical separation liquid was treated with the resin, the amount of unadsorbed L-α-aminobutyric acid that passed through the resin was 0.01 mol, and the outflow rate was 1.9%.

Also, in the first half of the tower, add 2N hydrochloric acid, 2. l-8v
= l (h t) to regenerate the ion exchange resin, the amount of L-α-aminobutyric acid hydrochloride was 0.01 mol and the amount of NaCl was 1.20 mol.

The above relationships are shown in Table 1.

Example 2 The same procedure as in Example 1 was carried out except that 2N-ammonia was used as the eluent.

The results are shown in Table 1. Example 3 The same procedure as in Example 1 was carried out except that N-acetyl-DL-methionine was used as the α-(N-acyl)-DL-amino acid.

The conditions and results are shown in Table 1.

Example 4 The same procedure as in Example 1 was carried out except that N-acetyl-DL-serine was used as the α-(N-acyl)-DL-amino acid.

The conditions and results are shown in Table 1.

Example 5 The experiment was carried out in the same manner as in Example 1, except that two diamond ion AsKIBs were used, and the experimental scale was as shown in Table 1.

The conditions and results are shown in Table 1.

Comparative Example I Amberlite ■l as H-type strongly acidic cation exchange resin
2N-NH40H in the eluent in a single system using R120B alone
The same procedure as in Example 2 was carried out except that No. 2,07 was used.

The results are shown in Table 1. Comparative Example 2 2N-HCI 2.0. ! It was carried out in the same manner as Comparative Example 1 except that .

The results are shown in Table 1. From the above Examples and Comparative Examples, if the method of the present invention and the conventional method are compared in terms of yield and purity, the second
The table will pass.

Therefore, the concentration of the monoamino acid obtained in the present invention in the eluate is extremely high compared to the conventional single-unit method, and has great industrial value.

Next, the adsorption state of the optical separation liquid in the ion exchange resin layer in the method of the present invention can be read from Table 1 as shown in Table 3.

It can be seen from Table 3 that in the strongly acidic cation exchange resin, the adsorption band for cations such as Na1 and the adsorption band for L-amino acids are very clearly distinguished.

Claims (1)

[Claims] 1. An aqueous solution obtained by asymmetric hydrolysis of an α-(N-acyl)-DL-amino acid containing metal ions is made up of three parts, the first half and the second half, connected in series, with the same or different strong acidity. The metal ions are saturated in the first half of the resin layer, and the split L-amino acids are adsorbed in the second half, and then the L-amino acids are separated and collected. Features: A method for separating single amino acids.