JPS58177947A - Separation of beta-hydroxy-alpha-aminobutyric acid - Google Patents

Abstract

PURPOSE:To separate beta-hydroxy-alpha-aminobutyric acid into dl-threonine and allothrenoine, by using an ion exchange resin having iminodiacetic acid-type or polyamine-type exchange group. CONSTITUTION:beta-hydroxy-alpha-aminobutyric acid is separated into dl-threnonine and allothreonine by using an ion exchange resin havng iminodiacetic acid-type exchange group (e.g. Lewatit TP-207, OC-1041, poduct of Bayer AG.) or an ion exchange resin having polyamine-type exchange group (e.g. Diaion CR-20, product of Mitsubishi Chemical Co.). The ion exchange resin is usually packed in a proper column, an aqueous solution containing hydroxyaminobutyric acid is passed through the column, and the adsorbed compound is eluted with water. The initial portion of the eluted fractions contains dl-allothreonine, and the latter portion contains dl-threonine which is important from the viewpoint of nutrition. Accordingly, the components can be separated easily by this process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for separating β-hydroxy-α-aminobutyric acid into dl-threonine and di-allothreonine. β-Hydroxy-α-aminobutyric acid (hereinafter abbreviated as hydroxyaminobutyric acid) has two optically active carbon atoms.
There are four isomers called IJ--allothreonine.

Usually, it is the threo form that has physiological activity and nutritional value, and the allo form is said to have no such utility value. When hydroxyaminobutyric acid is produced using a chemical synthesis method, a mixture of dJl-threonine and dl-allothreonine is always obtained, so it is difficult to separate the useful dl-threonine from these products. Necessary and naru. Various methods have been proposed for a long time to separate d-northreonine and di-allothreonine. For example, methods are known in which lithium is separated as a lithium salt using a difference in solubility, oxalate is separated, or a complex with phosgene is separated.

All of these separation methods have drawbacks such as being inefficient, requiring complicated operations, and requiring auxiliary raw materials.

An object of the present invention is to provide an efficient method for separating dl-threonine and dllll loalothreonine, which eliminates the drawbacks of the above-mentioned conventional methods.

The inventors have proposed an efficient, simple and industrial continuous operation KJ
As a result of various studies on the separation method of It, d2-threonine and dJ--allothreonine, it was found that hydroxyaminobutyric acid was adsorbed on an ion exchange resin having an iminodiacetic acid type or polyamine type group as an exchange group, and then hydroxyaminobutyric acid was adsorbed with water. It was discovered that when eluted, d,i-threonine and dl-allothreonine can be separated by m-c-, leading to the completion of the present invention.

That is, the present invention is a method in which hydroxyaminobutyric acid is adsorbed on a chelate type ion exchange resin having an exchange group of iminodiacetic acid or polyamine type, and this is eluted with water.

According to the method of the present invention, dl-threonine, dJ-
-Allothreonine can be separated from sulco.

The ion exchange resin used in the method of the present invention has an iminodiacetic acid type exchange group, for example, Lewatit
TP-207, QC-1041 (product name)
V company), Dowex 50w A-1 (product name, Dow Chemical Company), Diamond Ion CRT-10 (product name,
Examples of products with polyamine-type exchange groups include Diaion CR-20 and CR-40 (manufactured by Mitsubishi Kasei Corporation).
(product name, manufactured by Mitsubishi Kasei Corporation), etc.

These ion exchange resins are usually packed into a suitable column and used. An aqueous solution containing hydroxyaminobutyric acid is injected into the resin layer packed in the column, and then eluted with water. The injection speed of the raw material aqueous solution to be injected and the lip water used for elution is Q when expressed in liquid hourly space velocity (LH8V).

A range of 0.01 to 20, sometimes 0.1 to 5, is suitable.

The amount of ion exchange resin relative to the amount of hydroxyaminobutyric acid treated is 20 to 100% per gram of hydroxyaminobutyric acid.
- is in the range.

dl-allothreonine flows out in the first fraction leaving the ion exchange resin column, and dll-threonine flows out in the latter fraction.

Therefore, after the injection of hydroxyaminobutyric acid, the next predetermined amount of hydroxyaminobutyric acid is injected when the latter fraction, dll-threonine, begins to flow out. - The amount of hydroxyaminobutyric acid to be injected in each cycle is determined by the type of resin used, the ratio of dl-threonine and dl-allothreonine contained in the hydroxyaminobutyric acid to be injected, the LH8V of the elution water, and the dl-threonine to be separated. It varies widely depending on the degree of purity required. Therefore, the amount of hydroxyaminobutyric acid injected during each cycle and the time of one cycle need to be adjusted experimentally.

d separated from hydroxyaminobutyric acid by the method of the present invention
l-Threonine is a useful compound used as an essential amino acid and as a feed additive.

The present invention will be explained below with reference to Examples.

Example-1 When glycine and acetaldehyde are reacted using caustic soda and basic copper carbonate as catalysts, dl-threonine 7
Producing hydroxyaminobutyric acid containing 0% and dz-70 threonine 30%1. Ta.

A resin column with an inner diameter of 18 m/fn and a length of 150 mm was
Chelate resin TP-207 manufactured by Inil Co., Ltd. was made into a type (
100 to 200 m < zJ) to form a separation column.

Deionized water was injected from the column L section under pressure of 2 to 9/εi. Aqueous solution 20 containing 3.5 hydroxyaminobutyric acid containing 70% of the above threo form and 30% of allo form
d was injected. The injection sample was eluted with deionized water by setting the column outlet nozzle opening so that the liquid hourly space velocity of the effluent was 158 r.

dl-allothreonine was eluted in the first fraction in which hydroxyaminobutyric acid was eluted, and dJ--threonine was eluted in the subsequent fraction.

purity 98% cr) dJL-Arosleoni 10°85;
Obtain 2゜0g of 95% pure dl-threonine1. Ta.

0.5 g of a mixture of di-allothreonine and dl-threonine was recovered.

Example 2 A resin column with an inner diameter of 18 m/im and a length of 180 cm was filled with polyamine type chelate resin CR-20 manufactured by Mitsubishi Kasei to prepare a separation column. Example for this separation column-
Inject 20Wvt of an aqueous solution containing 39 of the same hydroxyaminobutyric acid as in 1, and add 2kg/deionized water from the top of the column.
Pressure was applied with crl and elution was carried out at a flow space velocity of 0°lHr.

The first fraction of hydroxyaminobutyric acid was di-allothreonin, and the later fractions were di-terthreonin. 1.8 g of dl-threonine with a purity of 92% - 005 g of dl-allothreonine with a purity of 95% were obtained.

patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 1) A method of separating β-hydroxy-α-aminobutyric acid into dl-threonine and allothreonine using an ion exchange resin having iminodiacetic acid or a polyamine type exchange group.