JPH02131494A - Crystal or sodium l-ascorbate 2-phosphate and production thereof - Google Patents

Abstract

NEW MATERIAL:Crystals of sodium L-ascorbate 2-phosphate. USE:Useful in various industrial fields of medicines, foods, cosmetics, etc. PREPARATION:A solution containing L-ascorbic acid 2-phosphate is regulated to pH8-10 with sodium hydroxide and an organic solvent selected from 1-5C aliphatic alcohols, 1-5C aliphatic saturated ketones and cyclic ethers is dripped into the solution so as to provide 30-80%(vol./vol.) concentration thereof in the solution while heating and refluxing the solution at 40-80 deg.C temperature for 4-7hr. The obtained solution is then allowed to stand at <=30 deg.C temperature to form the objective crystals.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to the use of thi-ascorbic acid-2-phosphate (hereinafter referred to as A
It is abbreviated as sA2P. ) crystals of sodium salt (hereinafter abbreviated as Na salt) and its production method.

Crystals of AsA2PNa salt are useful as a stabilized derivative of ascorbic acid, and can be used in pharmaceuticals, foods, cosmetics, and various other industrial fields.

Conventional technology Conventionally, many reports regarding AsA2F have been known.

For example, vitamins
n) Volume 41 (1970), pages 387 to 398, describe the chemistry and applications of ascorbic acid phosphate, and in particular, page 390 describes ascorbic acid phosphate.
Magnesium salt, sodium salt of 3-phosphate ester,
The properties of calcium salts are described. Ascorbic acid-
Regarding the properties of sodium 3-hephosphate, it is described that it is a colorless powder and does not easily crystallize. Note that ascorbic acid-3-phosphate in this document has been corrected to AsA2P on page 185 of Vitamin Vol. 51 (1985).

In addition, as a method for purifying AsA2P, there is a method using activated carbon (JP-A-59-5-1293, JP-A-59-1064).
94), method using strongly acidic cation exchange resin, method using strongly basic anion exchange resin (Japanese Patent Publication No. 45-449
7>, a method using a weakly basic or medium basic anion exchange resin (JP-A-62-30791), a method using a weak acid type chelate resin (JP-A-62-103096), and other methods are known.

JP-A-59-51293 states that it is preferable to decationize the purified AsA2P, which is the target product, and then convert it into a salt form. The salt forms listed include magnesium salt, calcium salt, sodium salt, and potassium salt. Furthermore, it is written that the solution containing the target product obtained in this way is subjected to the usual concentration step and crystallization step, but all the examples are related to magnesium salts, and the examples are all about magnesium salts. There is no mention of crystals. The inventor also attempted to obtain crystals of sodium salt by the method described in this publication, but
No crystals were formed, just a candy-like substance.

Problems to be Solved by the Invention Generally, AsA2P is put to practical use in the form of Mg salt, but the following problems arise in its purification process and in the use of the product.

(2) As AsA2PMg salt is of poor quality, it is difficult to obtain high purity AsA2PMg salt by crystallization. In particular, unreacted materials from the reaction raw materials and phosphorus compounds produced as by-products form insoluble Mg salts, making purification difficult.

(2) Since AsΔ2PMg salt is of low quality, it has a high moisture content and solvent residual rate, and it is not easy to remove attached moisture and solvent by drying.

■ AsA2PMg salt has a slow dissolution rate in water and tends to become candy-like. Therefore, in order to dissolve it at an industrially practical concentration, it is necessary to devise a dispersion method during dissolution.

(2) When AsA2PMg salt is used, it gradually becomes colored over time in a system where water is present.

Therefore, it is desired to develop 8sA2P in a stable and easy-to-handle form.

Means for Solving the Problems According to the present invention, stable, easy-to-handle, and highly purified AsA
2P is provided as a novel AsA2PNa salt crystal.

71 of the present invention. Crystals of sA2PNa salt can be obtained by adjusting a solution containing AsΔ2P to pH 8-10 with sodium hydroxide.
While heating and refluxing this solution at a temperature of 40 to 80°C, an organic solvent selected from lower aliphatic alcohols having 5 or less carbon atoms, aliphatic saturated ketones having 5 or less carbon atoms, and cyclic ethers is added to the solution. The concentration of 30-80% (v/v
) is gradually added to the solution over 4 to 7 hours, and then allowed to stand at a temperature of 30° C. or lower.

The physical properties of the AsΔ2PNa salt crystal of the present invention are shown below.

(1) Elemental analysis value (2) Molecular weight; 331.0 (from elemental analysis CsHsO
sPNa* j 'AH20) (3) X-ray diffraction pattern; Figure 1 shows the X-ray diffraction pattern obtained by measuring with the powder X-ray diffraction method using the Cu-K2 line. The numbers correspond to those in Table 1. The comparative intensities are peak 2 in the figure.
is expressed as 100.

Table 1 (4) Infrared absorption spectrum; The infrared absorption spectrum measured by the KBr tablet method is shown in FIG.

(5) Solubility in solvents: Easily soluble in water, but difficult to dissolve in lower alcohols and ketones.

Almost insoluble in ether.

Figure 3 shows the comparative dissolution rates of Na salt and Mg salt.

(6) Distinction between basic, acidic, and neutral; Weakly basic (7) Color of substance; Colorless and transparent (8) Crystal shape; Usually columnar crystals.

The starting solution used in the present invention may be any liquid containing AsA2P, such as an AsA2P solution, a metal salt solution of AsA2P, or a one-volume solution of an alkaline earth metal salt. For example, AsA2 is produced from ascorbic acid and a phosphate donor by the action of enzymes or microorganisms.
A P-containing liquid can be suitably used. Examples of metal salts include potassium salts, and examples of alkaline earth metal salts include magnesium salts and calcium salts.

When AsA2F is in the form of a salt, or when the As82P-containing solution contains metal ions such as alkali metals and alkaline earth metals, it is desirable to treat the aqueous solution with a suitable ion exchange resin to remove thione. . AsA2P is adsorbed onto an ion exchange resin, and 0. After elution with 1-2N diluted hydrochloric acid, the pH is adjusted to 1!! with thorium hydroxide.

pH adjustment with sodium hydroxide is usually 5 to 15N.
It is carried out in an aqueous solution of sodium hydroxide.

The AsA2P concentration in the solution after adjusting pHAl1 is 30-10
The amount is 0 g/1, preferably 50 to 80 g/β, and if necessary, it is diluted with water or concentrated by vacuum concentration or the like.

Next, the solution is heated under reflux for 40 to 80 tons, preferably at a temperature of 50 to 70°C, and the organic solvent is reduced to a concentration of 30 to 8.
The mixture is slowly added over 4 to 7 hours so that the concentration becomes 0% (v/v), and crystals are crystallized. Heating and refluxing is further continued for 2 to 10 hours as necessary.

Examples of the organic solvents used include lower aliphatic alcohols having 5 or less carbon atoms such as methanol and ethanol, aliphatic saturated ketones having 5 or less carbon atoms such as acetone, and cyclic ethers such as tetotehydefuran. These organic solvents may be used alone or in combination.

After heating and refluxing, if the mixture is left at a temperature of 30° C. or lower, the crystals will grow and ripen. The crystals are isolated by p-filtration, washed with the above-mentioned organic solvent, and then subjected to treatments such as vacuum drying to obtain a highly pure white crystalline AsA2PNa salt.

According to the method of the present invention, unreacted phosphorus compounds in the reaction solution of the ASA2P production reaction form highly soluble salts with sodium, so the amount of contamination in the product is small, crystals can be easily separated from the crystallization mother liquor, and they can be recycled. Fewer crystal operations are required.

Furthermore, the obtained crystals have a low water content, allowing easy removal of attached water and solvent, and a fast dissolution rate.

Aspects of the present invention will be illustrated by examples.

Example l. Pseudomonas azotocolligans ^TCC 1241
7, polypeptone 10g/R, meat extract 7g/12,
Yeast extract 5 g/l and NaCJ! 3g/
pH 7. Medium adjusted to 2 (hereinafter referred to as KM
It is abbreviated as 102 medium. ) Inoculate 30ml and incubate at 30℃ for 20
Cultured for hours. Next, 300 ml of KM I O 2 medium
12 ml of the seed culture solution obtained above was inoculated and cultured at 30° C. for 20 hours. The obtained culture solution was diluted with 10,000
Centrifuge at Xg for 10 minutes to remove wet bacterial cells 1. 8
g was obtained and stored frozen at 20°C. Cryopreserved bacterial cells 50
Ascorbic acid containing mg/ml (wet bacterial weight) 20
0 m! J, potassium birophosphate 200mM, sodium acetate buffer (p}I 4.0>100m
M, Naimeen S-215 (manufactured by NOF Corporation) 4g/j!
, xylene loml/j! 50 ml of the reaction solution with the composition of
Magnetic star? While stirring at 10 O rpm, adjust the PL to around 4.0 with sodium hydroxide.
The temperature was maintained at 40°C and the reaction was carried out for 36 hours. Obtained reaction solution (contains 30 g/1 of A s A2F) II! The p solution was passed through a slow closed p filter, and the p solution was passed through Prolyte A'10O (medium basic anion exchange resin, manufactured by Prolyte International).
The solution was passed through a column filled with 1 liter. Adsorbed A s A2P
was eluted with IN dilute hydrochloric acid.

The solution obtained by elution was adjusted to pH 9.0 with an aqueous solution of ION sodium hydroxide. Adjusted to 5.

The AsA2F concentration of this solution was concentrated under reduced pressure to 80 g/1.
．． Passed through a 45 micron Millipore filter. The p solution was heated to 60° C. under reflux, and while stirring, 900 ml of methanol was slowly added over about 6 hours, and then heated under reflux for 3 hours.

It was left at 30°C or lower overnight. The resulting crystals were filtered and washed with methanol. Next, vacuum drying at 40°C overnight yields 21.4 g of purified AsA2PNa salt crystals.
(Yield: $71%). Product analysis values of the obtained purified product are shown in Table 1.

Example 2. ΔsA2P20 obtained by a method similar to Example 1
．． The reaction solution containing Og/Il was adjusted to pH 4.0 with an IN aqueous sodium hydroxide solution. 0, 4 g of powdered activated carbon was added, and the mixture was left to stand at 50°C for 30 minutes to decolorize it, and then filtered. p
The solution was again adjusted to pH 9 with an aqueous solution of sodium hydroxide and sodium hydroxide.
．． 5 and concentrated under reduced pressure to AsA2P 80 g/l. 300 ml of the concentrated solution was heated to 60° C. under reflux and stirred, then 600 ml of acetone was slowly added over 6 hours, refluxed for an additional 3 hours, and then left at 5° C. for 3 hours.

The resulting crystals were filtered and washed with acetone. then 40
Vacuum dry at ℃ overnight to obtain the desired A SA 2 P N
16.5 g (yield: 80%) of purified crystals of a were obtained.

Example 3. I + W f of 50.0 g of AsΔ2PMg salt (unrefined product)
Dissolved in 1 liter of water. Add this solution to Diaion SK-I
B (strongly acidic cation exchange resin, manufactured by Mitsubishi Chemical Corporation) 500
The solution was passed through a column filled with 1.0 ml of the solution to remove thion.

The effluent was adjusted to pH 9 with an aqueous solution of IN sodium hydroxide.
．． After decolorizing with 5 g of powdered activated carbon, the mixture was filtered. p
The liquid was crystallized and dried in the same manner as in Example 1 to obtain the desired AsA2.
Purified PNa salt crystal product 4 2. 5 g (yield 85
%) was obtained. The product analysis values of the obtained purified product are shown in Table yg2.

Comparative Example AsA2P obtained by the same method as Example 1
20. The IN dilute hydrochloric acid solution containing Og/J was adjusted to pH 8 with IN magnesium hydroxide solution. The mixture was decolorized using powdered activated carbon and concentrated under reduced pressure until the concentration of A s A2P in the p solution became 50 g/1. The concentrated solution was heated to 60° C. and 900 ml of methanol was slowly added thereto over 6 hours while stirring. After further refluxing for 3 hours, the mixture was cooled and left at 30° C. or below overnight, and the resulting precipitate was filtered out and dried to obtain 22.5 g (yield: 75%) of a purified product of AsA2PMg salt. Product analysis values of the obtained purified product are shown in Table 2.

Table 2 (Product analysis of Na salt and 1 salt) According to the present invention, A
Crystals of sA2PNa salt are provided with high purity and high yield.

[Brief explanation of the drawing]

FIG. 1 is a powder X-ray diffraction pattern of AsA2PNa salt crystals of the present invention. Figure 2 is an infrared absorption spectrum of AsA2PNa salt crystal, and Figure 3 is an infrared absorption spectrum of AsA2PNa salt crystal, A
A comparison of the dissolution rates of sA2PMg salts. In the figure, 1 is AsA2P Na salt crystal, 2 is AsA2P
Indicates Mg salt. In addition, the vertical axis of FIG. 1 shows the diffraction intensity and the horizontal axis shows the diffraction angle, and the vertical axis of FIG. 2 shows the transmittance and the horizontal axis shows the wave number. In FIG. 3, the vertical axis shows the AsA2P concentration in the supernatant, and the horizontal axis shows the stirring dissolution time. FIG. 4 is a photograph (200x magnification) of AsA2PNa salt crystals.

Claims (8)

[Claims] (1) Crystals of L-ascorbic acid-2-phosphate sodium salt. (2) C_6H_6O_9PNa_3・1/2H_2O
A crystal of L-ascorbic acid-2-phosphate sodium salt shown by the molecular formula. (3) A solution containing L-ascorbic acid-2-phosphoric acid is adjusted to pH 8 to 10 with sodium hydroxide, and while heating and refluxing this solution at a temperature of 40 to 80°C, An organic solvent selected from lower aliphatic alcohols, aliphatic saturated ketones having 5 or less carbon atoms, and cyclic ethers is added so that the concentration in the solution is 30 to 80% (v/v).
L-ascorbic acid-2-
A method for producing crystalline L-ascorbic acid-2-phosphate sodium salt, which comprises crystallizing the sodium phosphate salt. (4) After decationizing the solution containing the metal salt or alkaline earth metal salt of L-ascorbic acid-2-phosphoric acid, the pH was adjusted to 8 to 10 with sodium hydroxide, and the solution was heated at 40 to 80°C. While heating and refluxing at a temperature of After gradually adding it to the solution over 4 to 7 hours so that
- A method for producing crystalline L-ascorbic acid-2-phosphate sodium salt, which comprises crystallizing the sodium phosphate salt. (5) The method for producing crystalline L-ascorbic acid-2-phosphate sodium salt according to claim (4), wherein the metal salt is a potassium salt. (6) The method for producing crystalline L-ascorbic acid-2-phosphate sodium salt according to claim (4), wherein the alkaline earth metal salt is a magnesium salt or a calcium salt. (7) Claims (3) and (4) characterized in that after adding the organic solvent, heating and refluxing is continued for an additional 2 to 10 hours.
A method for producing crystalline L-ascorbic acid-2-phosphate sodium salt. (8) The method for producing crystalline L-ascorbic acid-2-phosphoric acid according to claims (3) and (4), wherein the organic solvent is at least one of methanol, ethanol, acetone, or tetrahydrofuran.