JP2751344B2 - Purification method of β-cyclodextrin sulfate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to purification of alkali metal salts of β-cyclodextrin sulfate exhibiting physiological activities such as anti-inflammatory activity, immunostimulatory activity, anti-complement activity, and antitumor activity. About the method.

[Problems to be solved by the prior art and the invention]

As a method for purifying the β-cyclodextrin sulfate alkali metal salt, for example, methyl alcohol is added to a reaction solution containing β-cyclodextrin henicosasulfate pyridinium salt in USP 2,923,704 to precipitate the salt, which is then added to water. And then subjecting to salt exchange by adding aqueous sodium acetate, and adding ethyl alcohol thereto to precipitate and purify the desired β-cyclodextrin henicosa sulfate sodium salt. In USP 4,020,160, acetone or methanol is added to a reaction solvent of β-cyclodextrin polysulfate (such as triethylammonium salt) to precipitate the salt, which is then mixed with water, aqueous sodium acetate and ethyl alcohol. A method for purification from a solvent is described.

However, all of these methods require a large amount of solvent, are difficult to isolate because the precipitate has a small particle size and are difficult to filter, and are extremely complicated to obtain a target substance which is easy to handle and has high purity. It has drawbacks such as requiring a complicated process.

[Means for solving the problem]

The present invention is characterized in that a reaction solution containing an alkali metal salt of β-cyclodextrin sulfate is concentrated to dryness, the concentrate is dissolved in water, and this aqueous solution is mixed with a hydrophilic solvent to precipitate a target product. The present invention relates to a method for purifying an alkali metal salt of β-cyclodextrin sulfate.

The alkali metal salt of β-cyclodextrin sulfate used in the purification method of the present invention may be such that at least one of the hydroxyl groups of β-cyclodextrin is a sulfate alkali metal salt. Preferred specific examples include, for example, β-cyclodextrin monosulfate alkali metal salt, heptasulfate alkali metal salt, tetradeca sulfate alkali metal salt or henicosa sulfate alkali metal salt. Of these, β-cyclodextrin tetradeca sulfate alkali metal salt is preferable.

As the alkali metal of the β-cyclodextrin sulfate alkali metal salt, sodium or potassium is preferably used.

The reaction solution of β-cyclodextrin sulfate alkali metal salt used in the method of the present invention can be produced by a known method or a method similar thereto, or a method described in detail below.

 Hereinafter, the purification method of the present invention will be described for each step.

Concentration and Drying Step This step is performed by concentrating the reaction solution containing the β-cyclodextrin sulfate alkali metal salt under reduced pressure or normal pressure. The degree of reduced pressure is preferably about 0.01 to 500 mmHg, more preferably about 0.1 to 100 mmHg. The temperature is about 0-100 ° C, preferably about 10-50 ° C.

The time required for concentration and drying varies depending on the amount of solvent, temperature and the like, but is generally about 1 to 24 hours.

In this step, it is important to remove a reaction solvent, a liquid reaction reagent, or a liquid by-product generated by the reaction as much as possible to obtain a dry state.

Step of Precipitating Target Substance As the concentrate, a solid substance from which a liquid such as a solvent is removed as much as possible is used. After the concentrate is dissolved in water, the aqueous solution of the concentrate is added to the hydrophilic solvent, or the aqueous solution of the concentrate is added to the hydrophilic solvent.

Examples of the hydrophilic solvent include alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol; ketones such as acetone and methyl ethyl ketone; nitriles such as acetonitrile; and ethers such as dioxane and tetrahydrofuran. Preferably, they are alcohols. Particularly preferred is ethyl alcohol.

 This step is preferably performed with sufficient stirring.

The amount of water used to dissolve the concentrate is about 2 to 100 times, preferably about 5 to 20 times the weight of the concentrate.

The hydrophilic solvent is used in an amount of about 1 to 10 times, preferably about 1.5 to 5 times, the amount of water used for dissolving the concentrate.

The temperature is about 0 to 50 ° C, preferably about 10 to 30 ° C.

When the aqueous solution of the concentrate and the hydrophilic solvent are mixed with stirring, a gum-like or powder-like precipitate which is easy to handle is immediately generated. The precipitate is separated and collected by a usual classification method such as a gradient method and filtration.

However, when a gum-like substance is obtained as a precipitate, it is pulverized (triturate) in the above-mentioned hydrophilic solvent.
Alternatively, it may be purified by dissolving in water in the same manner as described above, mixing this aqueous solution with the above-mentioned hydrophilic solvent, and precipitating a powdery target substance.

The reaction solution containing the β-cyclodextrin sulfate alkali metal salt is produced by a known method (eg, the method described in US Pat. No. 2,923,704 or US Pat. No. 4,020,160) or a method known per se.

For example, β-cyclodextrin is sulfonated with a sulfonating agent and, if necessary, subjected to a salt exchange reaction to obtain β-cyclodextrin.
-A reaction solution containing a cyclodextrin sulfate alkali metal salt is obtained.

Examples of the sulfonating agent for β-cyclodextrin include sulfuric anhydride-organic amine complexes such as sulfur trioxide pyridine complex, sulfur trioxide trimethylamine complex, sulfur trioxide triethylamine complex, and sulfur trioxide dimethylformamide complex.
Alternatively, chlorosulfonic acid is used.

The sulfuric anhydride-organic amine complex is generally used in an amount of about 3 to 5 moles per anhydrous glycol unit of β-cyclodextrin.

The reaction is performed in a solvent. As the solvent, dimethylformamide, dimethylsulfoxide, pyridine or hexamethylphosphoramide is used. The amount of solvent used is β
About 10 to 50 times the weight of cyclodextrin is preferred.

The reaction temperature is about 40 to 80 ° C. The reaction time is about 5 to 24 hours.

When chlorosulfonic acid is used, the reaction is performed in the presence of an organic tertiary amine (eg, pyridine, triethylamine). For example, when using chlorosulfonic acid in pyridine, pyridine is used in an amount of about 15 to β-cyclodextrin.
Use 25 weight times. Chlorsulfonic acid is used in an amount of about 3 to 5 moles per anhydroglucose unit of β-cyclodextrin. In the reaction, first, pyridine was converted from about -10 to-
Cool to 20 ° C. Then, chlorosulfonic acid is added at the same temperature, and the mixture is heated to 70 ° C. to obtain a homogeneous solution. Then, β-cyclodextrin is added and the mixture is stirred at about 40 to 80 ° C. for about 5 to 24 hours.

Then, this solution is treated with a salt exchange reagent such as sodium acetate or potassium acetate, sodium hydroxide or potassium hydroxide (salt exchange reaction) to obtain a reaction solution containing β-cyclodextrin sulfate alkali metal salt. The salt exchange reagent is used in an amount of about 2 to 4 times the molar amount of the sulfonating agent used. This salt exchange reaction is usually performed in a water-containing solvent. The reaction temperature is about 10 to 50 ° C, preferably room temperature (about 20 to 30 ° C). Usually from about 1 at room temperature
Stirring for 10 hours completes the salt exchange reaction. At this time, stirring for 1 hour in a water-containing solvent gives β-cyclodextrin in which only the sulfate of the primary hydroxyl group is hydrolyzed.
A solution containing an alkali metal salt of cyclodextrin tetradeca sulfate is obtained.

In this case, a β-cyclodextrin sulfate organic amine salt is once isolated from a solution obtained by sulfonating β-cyclodextrin with a sulfonating agent, and then isolated with a salt exchange reagent described above to obtain β-cyclodextrin sulfate. A reaction solution containing an alkali metal salt may be obtained.

In order to precipitate the β-cyclodextrin sulfate organic amine salt, it is preferable to add a solvent having the same volume as the solution used for the sulfonation reaction, for example, ether, acetone, methylene chloride, ethyl alcohol, methyl alcohol and the like. The precipitated β-cyclodextrin sulfate organic amine salt is collected by a usual isolation and purification method, and then treated (salt exchange reaction) with the above-mentioned salt exchange reaction reagent to obtain β-cyclodextrin sulfate alkali metal salt. Can be obtained. The amount of the salt exchange reagent is suitably about 2 to 4 times the mol of the sulfonating agent used.

This salt exchange reaction is usually performed in an aqueous solvent. Stir at room temperature for about 1 to 10 hours. At this time, stirring for 1 hour in water gives a solution containing β-cyclodextrin tetradeca sulfate alkali metal salt in which only the sulfate of the primary hydroxyl group of β-cyclodextrin is hydrolyzed.

Examples are shown below to specifically describe the purification method of the present invention.

〔Example〕

Example 1 β-cyclodextrin tetradeca sulfate sodium salt (a) 5 g of β-cyclodextrin was dissolved in 250 ml of dimethylformamide, and while stirring at 70 ° C., 15 g of sulfur trioxide trimethylamine complex salt was added in 5 minutes, followed by the same temperature. And stirred for 16 hours. After cooling, 250 ml of ethanol was added and insolubles were obtained by decantation, and the insolubles were washed with a small amount of ethanol. The residue was dissolved in 250 ml of water, the insoluble matter was removed by filtration, 75 ml of a 30 w / v% aqueous sodium acetate solution was added to the filtrate, and the mixture was stirred at room temperature for 1 hour.

(B) The reaction solution containing the β-cyclodextrin tetradeca sulfate ester sodium salt obtained above was concentrated to dryness under reduced pressure (20 to 25 mmHg) in a water bath at ℃ 60 ° C. The concentrate was dissolved in 75 ml of water, 150 ml of ethanol was added, and the precipitated gum-like solid was collected by decantation, further powdered with 30 ml of ethanol, filtered, and dried to obtain 10.3 g of the title compound as a colorless powder. was gotten.

Elemental analysis: C ₄₂ H ₅₆ O ₇₇ S ₁₄ Na ₁₄ Calculated: C 19.68; H 2.20; S 17.51 (%) Found: C 20.67; H 3.40; S 16.29 (%) ▲ [α] ²² _D ▼ + 83 0.5% (c = 1.55, water) Water content 1.5w / w% (Karl Fischer method) Example 2 β-cyclodextrin tetradeca sulfate sodium salt (a) 140 ml of pyridine was cooled to -20 ° C and stirred. After slowly adding 22 ml of chlorosulfonic acid, the mixture was heated to obtain a homogeneous solution, and 5.6 g of β-cyclodextrin was added, followed by reaction at 70 ° C. for 15 hours. After cooling, ethanol 500m
l was added and decanted, and the pyridinium salt was washed with ethanol. The residue was dissolved in 250 ml of water and filtered, and then the filtrate was mixed with 75 ml of a 30 w / v% aqueous sodium acetate solution and stirred at room temperature for 1 hour.

(B) The reaction solution containing β-cyclodextrin tetradeca sulfate sodium salt was placed under reduced pressure (60 ° C., 20 to 2
Concentrate to dryness to 5mmHg). 80 ml of water was added to the residue to dissolve it, and 160 ml of ethanol was added to obtain a precipitated solid by decantation.Further, 40 ml of ethanol was added to obtain a powder, which was filtered and dried to obtain 11.7 g of the title compound as a colorless powder. .

Elemental analysis value: C ₄₂ H ₅₆ O ₇₇ S ₁₄ Na ₁₄ Calculated: C 19.68; H 2.20; S 17.51 (%) Found: C 21.07; H 3.56; S 15.95 (%) ▲ [α] ²² _D ▼ +84 .2 ゜ (c = 1.225, water) Water content 1.4 w / w% (Karl Fischer method) [Effect of the Invention] The purification method of the present invention is simple in operation, easy to isolate precipitates, and high in purity. A good β-cyclodextrin sulfate alkali metal salt is obtained.

Claims (1)

(57) [Claims] 1. A reaction solution containing an alkali metal salt of β-cyclodextrin sulfate is concentrated to dryness, the concentrate is dissolved in water, and the aqueous solution is mixed with a hydrophilic solvent to precipitate the desired product. A method for purifying an alkali metal salt of β-cyclodextrin sulfate.