JPS6121184A - Preparation of water-soluble anstioxidant - Google Patents

Abstract

PURPOSE:To obtain a water-soluble antioxidant having high oxidation prevention ability, by bringing a water-insoluble tocopherol into contact with cyclodextrin under specific conditions, so that tocopherol is included in cyclodextrin. CONSTITUTION:For example, cyclodextrin is packed into a column, tocopherol is dissolved in a solvent such as ethyl ether, etc. to dissolve only tocopherol, made to flow into the column, then, cyclodextrin is taken out, and the colvent is removed to give the aimed antioxidant wherein tocopherol is included in cyclodextrin. USE:An inhibitor for fading of water-soluble dye, an inhibitor for deterioration of water-soluble plastic.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a water-soluble antioxidant and a method for producing the same.

1 Conventional Technology 1 Antioxidants have been widely used to prevent the oxidation of oils and fats, to prevent the deterioration of plastics, and to prevent the fading of dyes. However, most of them are oil-soluble, and only ascorbic acid, which has a low antioxidant ability, can be used to prevent the fading of water-soluble dyes and the deterioration of water-soluble plastics.

In this situation, the present inventors found that although tocopherols have a relatively large antioxidant capacity, they cannot be used to prevent fading of water-soluble dyes or prevent deterioration of water-soluble plastics due to their water insolubility. However, they realized that if they were made water-soluble, they could be used as the above-mentioned antioxidant, and discovered that by including tocopherol in cyclodextrin, it was possible to obtain a water-soluble antioxidant with high antioxidant ability. , we have completed the present invention.

[Summary of the Invention 1 That is, the present invention is a water-soluble cyclodextrin-tocopherol clathrate compound, which is characterized in that a water-insoluble tocopherol and a cyclodextrin are made into a water-soluble cyclodextrin-tocopherol clathrate compound by contacting at least the tocopherol with the cyclodextrin in a solution state. This is a method for producing a synthetic antioxidant.

In the present invention, embodiments in which at least tocopherol is brought into contact with cyclodextrin in a solution state include:
Any contact method can be used. For example, contact can be advantageously carried out by packing cyclodextrin in the same phase into a column, dissolving tocopherol in a solvent that dissolves only tocopherol and flowing it through the column, and then taking out the cyclodextrin and removing the solvent. Alternatively, it may be carried out by dissolving both tocopherol and cyclodextrin in a solvent that dissolves only one of them, mixing the obtained tocopherol solution and cyclodextrin solution, and removing the solvent that dissolves only tocopherol while stirring. .

Tocopherols that can be used in the present invention include a
-, β-, ar, δ-tocopherol, 5°7-dimethyl tocol, 7-methyl docol, 5-notyl tocol, tocol, a+, β-9γ-1δ-tocotrienol and the like.

Further, examples of the cyclodextrin that can be used in the present invention include a+, β-1γ-cyclodextrin, and the like.

In the present invention, dichloroethane, chloroform, carbon disulfide, ethyl ether, etc. can be used as the tm medium in which only tocopherol can be dissolved. Further, in the present invention, examples of the solvent that dissolves only cyclodextrin include water, glycerin, and the like.

CI-) Core Erol-β- obtained by the method of the present invention
FIG. 1 shows the ultraviolet absorption spectrum of an aqueous solution of cyclodextrin clathrate compound. This figure shows that (1-) coreerol is water-soluble.

Next, add a methylene blue aqueous solution with a strength of 150IIIW/
Figure 2 curve (a) shows the change in absorbance over time at 660 nm when Cl62 was irradiated with ultra-high pressure mercury lamp light.

The reaction rate constant is 8×10 −3 min −1, and it can be seen that the absorbance decreases over time. Next, the change in absorbance over time when the Q-) coreerol-β-cyclodextrin clathrate compound was added to the methylene blue aqueous solution was measured in the second step.
Figure curve (b) shows this. The reaction rate constant is = 1.2X10
-''min-1, and it can be seen that the decrease in absorbance over time becomes very small.

It is thought that the photobleaching property of methylene blue is due to singlet oxygen produced by methylene blue due to light, and that a-tocopherol quenches this. Therefore, it can be seen that the toco7erol-cyclodextrin clathrate compound is effective as a water-soluble antioxidant.

[Embodiment 1 of the invention The present invention will be explained below based on examples.

Example 1 10 parts by weight of β-cyclodextrin was added to 1 cmφX10
cm column, and a solution of 0.2 parts by weight of O-)coreerol dissolved in 100 parts by weight of ethyl ether was poured into the column. After the solution is completely discharged by reducing the pressure, β-cyclodextrin (a-toco7erol-β-cyclotextrin clathrate compound) is taken out from the column and dried day and night using a vacuum pump. This product was dissolved in 1,000 parts by weight of water, and centrifuged at 10° C. and a pressure of 5,000×g for 10 minutes to remove the top of the α-toco7erol-β-cyclodextrin clathrate.

Separately, prepare a solution of 5mg of methylene blue in 100+nl of water, and add 1c of this methylene blue solution.
Transfer 0.5 ml to a cell for spectrometry, and add 2.5 ml of the a-toco7erol-β-cyclodextrin clathrate solution. This product had an absorbance of 0.65 at 660 nm. When this was irradiated with ultra-high pressure mercury lamp light of 150 mW/am2 for 45 minutes, the absorbance became 0.63.

Example 2 10 parts by weight of a-cyclodextrin was added to 1 co+φX1
A 0 cm column was packed, and 0.1 parts by weight of β-tocopherol dissolved in 100 parts by weight of chloroform was poured into the column. After the solution was completely discharged under reduced pressure, α-cyclodextrin (β-toco7erol-a-cyclodextrin clathrate) was taken out from the column and dried overnight with a vacuum pump. This product was dissolved in 1000 parts by weight of water and centrifuged at 10° C. and a pressure of 5000×g for 10 minutes to remove the top of the β-toco7erol-a-cyclodextrin clathrate.

Add 0.5+nl of the methylene blue solution prepared in Example 1 to a 1cI11 spectrometer cell, and add 2.5nl of the aqueous solution of β-toco7erol-α-cyclodextrin clathrate.
+nl added. This item has an absorbance of 0.6 at 660 nm.
It was 5. When this was irradiated with ultra-high pressure mercury lamp light of 150 mW/cm2 for 45 minutes, the absorbance became 0.62.

Examples 3 to 5 Inclusion compounds were prepared in the same manner as in Example 1, except that the tocopherol and cyclodextrin shown in the table below were used, and absorbance changes were observed in the same manner as in Example 1, except for the irradiation time shown in the table. Examined.

Example 6 1 part by weight of β-cyclodextrin is dissolved in 100 parts by weight of water. 0.1 part by weight of (1-) co-7erol to 10
Dissolve in weight parts of ethyl ether.

Next, both solutions are mixed and the ethyl ether is evaporated by reducing the pressure while stirring vigorously in a beaker using a magnetic stirrer. This thing 5000X
Remove the precipitate by centrifugation at a pressure of g for 10 minutes.

Separately, prepare a solution of 5B methylene blue in 100ml of water, add 0.5ml of this methylene blue solution to a 1cm spectroscopic measurement cell, and add the a-toco7erol-β-cyclodextrin clathrate solution from above. Add 2,5n+1. This product had an absorbance of 0.65 at 660 nm. When this was irradiated with ultra-high pressure mercury lamp light of 150 mW/cm2 for 45 minutes, the absorbance became 0.63.

Example 7 1 part by weight of a-cyclodextrin is dissolved in 100 parts by weight of water. 0.01 parts by weight of β-tocopherol
Dissolve in parts by weight of dichloroethane.

Both are mixed, and dichloroethane is evaporated by reducing the pressure while vigorously stirring with a magnetic stirrer in a beaker. A white precipitate forms, which is collected by filtration. The collected precipitate is dried overnight using a vacuum pump. Dissolve this product in 100 parts by weight of water, and
The mixture was centrifuged at a pressure of 00×g for 10 minutes to remove the β-toco7erol-a-cyclodextrin clathrate.

Take 0.5+nl of the methylene flue solution prepared in Example 6 into a 1cm spectroscopic measurement cell, and add β-toco7erol-a.
- Added 2.5 l of an aqueous solution of cyclodextrin clathrate. This product had an absorbance of 0.65 at 660r+m. When this was irradiated with ultra-high pressure mercury lamp light of 150 +nW/c+n2 for 45 minutes, the absorbance became 0.62.

Examples 8 to 10 Inclusion compounds were prepared in the same manner as in Example 6, except that the tocopherol and cyclodextrin shown in the table below were used, and absorbance changes were observed in the same manner as in Example 6, except for the irradiation time shown in the table. Examined.

Comparative Examples 1 to 3 0.5ml of the methylene blue solution prepared in Example 1 was added to the icm
Place the sample in a spectroscopic cell and add 2.5 ml of distilled water. The absorbance of this material at 660 nm was examined, and the absorbance when it was irradiated with ultra-high pressure mercury lamp light of 150 mW/e+n2 was determined. The table below shows the light irradiation time and the absorbance after irradiation.

As can be seen from the table, it is clear that the inclusion compounds according to the invention prevent photobleaching.

[Effects of the Invention] As described above, the present invention has the effect of preventing discoloration of water-soluble dyes and preventing deterioration of water-soluble plastics, and can also be added to foods to prevent their oxidative deterioration.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the ultraviolet absorption spectrum of the a-) co-erol-β-cyclodextrin clathrate according to the present invention, and FIG. FIG. 3 is a diagram showing a photobleaching curve when a coupling compound is added. Act ``X battle hundred x Liu

Claims (6)

[Claims] (1) A method for producing a water-soluble antioxidant, comprising forming a water-insoluble tocopherol and a cyclodextrin into a water-soluble cyclodextrin-tocopherol clathrate compound by contacting at least the tocopherol with the cyclodextrin in a solution state. . (2) The contacting is carried out by packing the cyclodextrin into a column, dissolving the tocopherol in a solvent that dissolves only tocopherol and flowing it through the column, and then taking out the cyclodextrin and removing the solvent. A method for producing a water-soluble antioxidant. (3) The contact involves dissolving tocopherol and cyclodextrin in a solvent that dissolves only one of them, and mixing the obtained tocopherol solution and cyclodextrin solution,
The method for producing a water-soluble antioxidant according to claim 1, which is carried out by removing a solvent that dissolves only tocopherol while stirring. (4) The method for producing a water-soluble antioxidant according to any one of claims 1, 2, and 3, wherein the tocopherol is α-tocopherol. (5) The method for producing a water-soluble antioxidant according to any one of claims 1, 2, 3, or 4, wherein the solvent that dissolves only tocopherol is ethyl ether. (6) The method for producing a water-soluble antioxidant according to any one of claims 1, 3, 4, and 5, wherein the solvent that dissolves only cyclodextrin is water.