JP3117949B2 - Crystals of L-ascorbic acid-2-phosphate sodium salt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a sodium salt (hereinafter abbreviated as Na salt) crystal of L-ascorbic acid-2-phosphate (hereinafter abbreviated as AsA2P). Crystals of AsA2PNa salt are useful as stabilized derivatives of ascorbic acid, and can be used in pharmaceuticals, foods, cosmetics, and various other industrial fields.

[0002]

2. Description of the Related Art Hitherto, many reports on AsA2P have been known. For example, vitamins (Vitamin
s; Japan) 41 (1970) 387-39
Page 8 describes the chemistry and application of ascorbic acid phosphates, and page 390 describes the properties of magnesium, sodium and calcium salts of ascorbic acid-3-phosphate. The property of sodium ascorbic acid-3-phosphate is described as a colorless powder which is difficult to crystallize. In addition, ascorbic acid-3-phosphate in this document has been corrected to AsA2P in 185 pages of Vitamin 51 (1985).

In addition, as a method for purifying AsA2P, a method using activated carbon (JP-A-59-51293, JP-A-59-59293).
-106494), a method using a strongly acidic cation exchange resin, and a method using a strongly basic anion exchange resin (Japanese Patent Publication No. Sho 4).
5-4497), a method using a weakly basic or medium basic anion exchange resin (JP-A-62-30791), and a method using a weak acid-type chelate resin (JP-A-62-10309).
Methods such as 6) are known.

JP-A-59-51293 discloses that after purifying AsA2P, which is an object, after decationization,
It is stated that salt form is preferred. As the salt form, magnesium salt, calcium salt, sodium salt, potassium salt and the like are described. Furthermore, it is described that the liquid containing the target substance obtained in this manner is subjected to a concentration step and a crystallization step which are usually performed, but all the examples are directed to magnesium salts, and to the sodium salt crystals. Is not written. In addition, the present inventor tried to obtain sodium salt crystals by the method described in this publication, but could not produce crystals but merely produced candy.

[0005]

Generally, AsA2P is put into practical use in the form of Mg salt, but the following points are problematic in the purification process and in the use of the product. Since AsA2PMg salt is amorphous, it is difficult to obtain high purity AsA2PMg salt by crystallization. In particular, the unreacted reaction raw material and the phosphorus compound generated as a by-product form an insoluble Mg salt, making purification difficult. Since AsA2PMg salt is amorphous, it has a high water content and a high solvent residual ratio, and it is not easy to remove adhering moisture and solvent by drying. AsA2PMg salt has a slow dissolution rate in water and tends to be candy-like. Therefore, in order to dissolve it in an industrially practical concentration, it is necessary to devise a dispersion method at the time of dissolution. In the case where AsA2PMg salt is used, in a system in which water is present, the color gradually increases over time.

Accordingly, a stable and easy-to-handle AsA2
The development of P is desired.

[0007]

According to the present invention, a novel AsA2P which is stable, easy to handle and has high purity is obtained.
Provided as crystals of the PNa salt. Further, according to the present invention, there is provided a crystal of an AsA2PNa salt represented by the molecular formula of C ₆ H ₆ O ₉ PNa ₃ .1 / 2H ₂ O.

Further, according to the present invention, in the powder X-ray diffraction using Cu-K ₂ ray, the analysis pattern of the plane spacing d (Å) and the comparative intensity [expressed in% in ()] is within the range of experimental error. Then, 12.8 (9), 12.017 (100),
7.893 (3), 7.589 (48), 5.921
(7), 5.368 (5), 5.049 (18), 4.
883 (13), 4.691 (45), 4.514 (1
0), 4.469 (10), 4.055 (25), 3.
751 (13), 3.637 (28), 3.594 (2
5), 3.538 (15), 3.367 (12),
311 (29), 3.281 (31), 2.882
(9), 2.807 (19), 2.765 (51),
2.724 (53), 2.645 (14), 2.509
(11), 2.472 (11), 2.375 (10),
2.276 (21), 2.189 (9), 2.108
(9), 1.91 (7), 1.906 (4), 1.83
9 (8), which is a crystal of sodium L-ascorbic acid-2-phosphate.

According to the present invention, the solution containing AsA2P is adjusted to pH 8 to 10 with sodium hydroxide,
While heating and refluxing this solution at a temperature of 40 to 80 ° C,
An organic solvent selected from a lower aliphatic alcohol having 5 or less carbon atoms, an aliphatic saturated ketone having 5 or less carbon atoms and a cyclic ether is used for 4 to 7 hours so that the concentration in the solution becomes 30 to 80% (v / v). And slowly added to the solution,
There is provided a crystal of an AsA2PNa salt obtained by standing at a temperature of not more than ° C.

Further, according to the present invention, a solution containing a metal salt or an alkaline earth metal salt of AsA2P is decationized, adjusted to pH 8 to 10 with sodium hydroxide, and the solution is heated to a temperature of 40 to 80 ° C. The concentration of an organic solvent selected from a lower aliphatic alcohol having 5 or less carbon atoms, an aliphatic saturated ketone having 5 or less carbon atoms and a cyclic ether in a solution becomes 30 to 80% (v / v) while heating and refluxing. After slowly adding to the solution over 4 to 7 hours,
There is provided a crystal of an AsA2PNa salt obtained by standing at a temperature of 0 ° C. or lower.

DETAILED DESCRIPTION OF THE INVENTION The physical properties of the crystals of the AsA2PNa salt of the present invention are shown below. (1) Elemental analysis value

[0012]

[Table 1]

(2) Molecular weight; 331.0 (3) X-ray diffraction diagram; FIG. 1 shows an X-ray diffraction pattern obtained by the powder X-ray diffraction method using Cu-K ₂ rays. The numbers in the figure correspond to the numbers in Table 2. The comparative intensity is shown with the peak 2 in the figure as 100.

[0014]

[Table 2]

(4) Infrared absorption spectrum: KB
FIG. 2 shows the infrared absorption spectrum measured by the r-tablet method. (5) Solubility in solvents; easily soluble in water, but hardly soluble in lower alcohols and ketones. Hardly soluble in ether. FIG. 3 shows the comparative dissolution rates of Na salt and Mg salt.

(6) distinction of basic, acidic and neutral; weakly basic (7) color of substance; colorless and transparent (8) crystal form; usually columnar.

The starting solution used in the present invention may be any solution containing AsA2P, such as a AsA2P solution, a metal salt solution of AsA2P or an alkaline earth metal salt solution. For example, an AsA2P-containing liquid produced by the action of an enzyme or a microorganism from ascorbic acid and a phosphate donor can be suitably used. Metal salts include potassium salts, and alkaline earth metal salts include magnesium salts and calcium salts.

When AsA2P is in the form of a salt, or when the AsA2P-containing liquid contains a metal ion such as an alkali metal or an alkaline earth metal, the aqueous solution may be treated with an appropriate ion exchange resin to decationize. desirable.
AsA2P is adsorbed on an ion exchange resin, and 0.1-2N
After elution with dilute hydrochloric acid, the pH is adjusted with sodium hydroxide.

The pH adjustment with sodium hydroxide is usually performed with a 5 to 15N aqueous sodium hydroxide solution. pH
The concentration of AsA2P in the adjusted solution is 30 to 100 g /
l, preferably 50 to 80 g / l, and if necessary, it is diluted with water or concentrated by vacuum concentration or the like.
Then, the solution is heated to reflux at a temperature of 40 to 80 ° C., preferably 50 to 70 ° C., and an organic solvent having a concentration of 30 to 8 is added.
Crystallize by slow addition over 4-7 hours to 0% (v / v). If necessary, heat reflux is continued for 2 to 10 hours.

The organic solvent used is methanol,
A lower aliphatic alcohol having 5 or less carbon atoms such as ethanol,
Examples thereof include aliphatic saturated ketones having 5 or less carbon atoms such as acetone, and cyclic ethers such as tetotehydrofuran. These organic solvents may be used alone or in combination. When left at a temperature of 30 ° C. or less after heating and reflux, the crystallized crystals grow and mature. The crystals are isolated by filtration, washed with the organic solvent, and then dried in a vacuum or the like to obtain a high-purity white crystalline AsA2PNa salt.

According to the method of the present invention, the unreacted phosphorus compound in the reaction solution of the AsA2P formation reaction forms a salt with high solubility with sodium, so that the amount of the unreacted phosphorus compound mixed into the product is small, and the separability of crystals from the crystallization mother liquor is low. Good, the number of recrystallization operations is small. The obtained crystals have a low water content, easy removal of adhering moisture and solvent, and high dissolution rate.

The embodiments of the present invention will be described by way of examples.

[0023]

【Example】

Example 1 Pseudomonas azotocolligans ATCC 124
17 at pH containing polypeptone 10 g / l, meat extract 7 g / l, yeast extract 5 g / l and NaCl 3 g / l
The cells were inoculated into 30 ml of a medium adjusted to 7.2 (hereinafter abbreviated as KM102 medium) and cultured at 30 ° C. for 20 hours.
Then, 12 ml of the seed culture obtained above was inoculated into 300 ml of KM102 medium, and cultured at 30 ° C. for 20 hours.
The obtained culture was centrifuged at 10,000 × g for 10 minutes to obtain 11.8 g of wet cells, which were stored frozen at −20 ° C. 200 mM ascorbic acid, potassium pyrophosphate 20 containing 50 mg / ml (wet cell weight) of cryopreserved cells
0 mM, sodium acetate buffer (pH 4.0) 100
mM, Nimeen S-215 (manufactured by NOF Corporation) 4 g /
l, 50 ml of a reaction solution having a composition of xylene 10 ml / l,
While stirring at 100 rpm with a magnetic stirrer, the pH was adjusted to around 4.0 with sodium hydroxide,
The reaction was maintained at 0 ° C. for 36 hours. The obtained reaction solution (A
Contains 30 g / l of sA2P. ) Slowly sterilize 1 liter,
The solution was treated with Prolite A100 (medium basic anion exchange resin,
The solution was passed through a tower filled with 1 liter (prolight international). The adsorbed AsA2P was eluted with 1N diluted hydrochloric acid.

The solution obtained by the elution was adjusted to pH 9.5 with a 10N aqueous sodium hydroxide solution. As of this liquid
After concentration under reduced pressure to a concentration of A2P of 80 g / l, the mixture was passed through a 0.45 micron Millipore filter. The solution was heated to 60 ° C. under reflux and stirred, and 900 ml of methanol was added for about 6 hours.
The mixture was added slowly over a period of time, and then heated under reflux for 3 hours. It was left overnight at 30 ° C. or lower. Have the resulting crystals,
Washed with methanol. Then, vacuum drying at 40 ° C. overnight is carried out to purify the desired crystal of AsA2PNa salt 21.4.
g (yield 71%) was obtained. Table 3 shows the product analysis values of the obtained purified product.

Example 2 AsA2P 2 obtained by the same method as in Example 1
The reaction solution containing 0.0 g / l was adjusted to pH 4.0 with a 1N aqueous sodium hydroxide solution, and 4 g of powdered activated carbon was added. The solution was adjusted to pH 9.5 again with a 1N aqueous solution of sodium hydroxide.
It was concentrated under reduced pressure to 80 g / l of sA2P. Heat 300 ml of the concentrated solution to 60 ° C. while stirring under reflux, acetone 6
00 ml was added slowly over 6 hours, refluxed for 3 hours, and left at 5 ° C. for 3 hours. The resulting crystals were collected and washed with acetone. Then, vacuum drying was carried out at 40 ° C. overnight to obtain 16.5 g (yield: 80%) of the purified AsA2PNa crystal.

Example 3 50.0 g of AsA2PMg salt (unrefined product) was dissolved in 1 liter of purified water. This solution was added to Diaion SK-1B.
(Strongly acidic cation exchange resin, manufactured by Mitsubishi Kasei Corporation) 500ml
The solution was passed through a column packed with and decationized. 1N effluent
The pH was adjusted to 9.5 with an aqueous sodium hydroxide solution, and the mixture was decolorized with 5 g of powdered activated carbon and passed through. The liquid was crystallized as in Example 1,
Purified purified crystals of the desired AsA2PNa salt 4
2.5 g (85% yield) were obtained. Table 3 shows the product analysis values of the obtained purified product.

Comparative Example AsA2P 2 obtained by the same method as in Example 1.
A 1N dilute hydrochloric acid solution containing 0.0 g / l was adjusted to pH 8 with a 1N magnesium hydroxide solution. The solution was decolorized with activated carbon powder, concentrated under reduced pressure until the concentration of AsA2P in the solution became 50 g / l, and 900 ml of methanol was slowly added thereto over 6 hours while heating and stirring the concentrated solution at 60 ° C. After further refluxing for 3 hours, the mixture was cooled, left standing at 30 ° C. or less overnight, and the precipitate formed was dried.
2.5 g (75% yield) were obtained. Table 3 shows the product analysis values of the obtained purified product.

[0028]

[Table 3]

[0029]

According to the present invention, crystals of AsA2PNa salt are provided with high purity and high yield.

[Brief description of the drawings]

FIG. 1 is a powder X-ray diffraction pattern of the AsA2PNa salt crystal of the present invention. The vertical axis indicates the diffraction intensity, and the horizontal axis indicates the diffraction angle.

FIG. 2 is an infrared absorption spectrum of an AsA2PNa salt crystal. The vertical axis shows the transmittance, and the horizontal axis shows the wave number.

FIG. 3 is a comparison of the dissolution rates of AsA2PNa salt crystals and AsA2PMg salts. In the figure, 1 is AsA2PN
a salt crystal, 2 represents AsA2PMg salt. The vertical axis indicates the AsA2P concentration in the supernatant, and the horizontal axis indicates the stirring and dissolution time.

FIG. 4 is a photograph (× 200) of an AsA2PNa salt crystal.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-B-48-15605 (JP, B1) BIOCHEMICAL MEDICAL INE, Vol. Report Chem. Pharm. Bull. 30, Vol. 3, No. 3, pp. 1024-1029 (1982) Vitamine (Japan), Vol. 41, No. 6, pp. 387-398 (1970) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) C07F 9/655 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] 1. X-ray powder diffraction using Cu—K ₂ radiation,
Surface spacing d (Å) and comparative strength [expressed in% in ()]
Analysis pattern of 12.8 (9), 12.017 (1
00), 7.893 (3), 7.589 (48), 5.
921 (7), 5.368 (5), 5.049 (1
8), 4.883 (13), 4.691 (45), 4.
514 (10), 4.469 (10), 4.055 (2
5) 3.751 (13), 3.637 (28), 3.
594 (25), 3.538 (15), 3.367 (1
2) 3.311 (29), 3.281 (31), 2.
882 (9), 2.807 (19), 2.765 (5
1), 2.724 (53), 2.645 (14), 2.
509 (11), 2.472 (11), 2.375 (1
0), 2.276 (21), 2.189 (9), 2.1
08 (9), 1.91 (7), 1.906 (4), 1.
839 (8), a crystal of sodium L-ascorbic acid-2-phosphate.