JP4640996B2 - Method for producing reduced glutathione - Google Patents

Description

  The present invention relates to a method for producing reduced glutathione that reduces oxidized glutathione.

As a method for producing reduced glutathione, a method of reducing oxidized glutathione has been conventionally performed. In general, various reactions for reducing a disulfide bond to form a thiol group are known. Typical examples include a method using a thiol reducing agent such as mercaptoethanol, a method of electrolytic reduction, a reducing agent such as sodium borohydride. And a method using an enzyme such as glutathione reductase are known.
Regarding the reduction of oxidized glutathione, application of these methods in consideration of the characteristics of peptides, optical activity, etc. has been studied. For example, a method of reacting a mercapto lower alcohol and a divalent water-soluble lead salt, liquid ammonia Method of reacting with sodium, method using metal such as zinc and mineral acid, method using sodium sulfide, sodium cyanide, phosphonium iodide or alkali metal borohydride, catalytic reduction method, electrolytic reduction method, hydrogen storage alloy The reduction method by the method (Patent Document 1, Non-Patent Document 1) and the like have been reported.

However, when these methods are applied to foods and pharmaceuticals, the reagents are expensive, the reactor is expensive, the reaction in the aqueous solution does not proceed sufficiently, or it is generated during the reaction. There is a problem that removal of by-products is difficult, and the development of a better method has been desired.
Japanese Patent Publication Nos. 40-16529, 46-33938, 46-33939, 47-8053, 57-16196, and Japanese Patent Laid-Open No. 4-154730. J. Biol. Chem. 1946 116 469, Biochem. J. 1921 15 292, Biochem. J. 1935 29 1622, Biochem. Z. 1931 230 353, J. Org. Chem. 1957 22 805

  An object of the present invention is to provide a simple and industrially advantageous method for reducing oxidized glutathione, in which the reaction proceeds in a high yield even in an aqueous solution without requiring special equipment.

As a result of research to solve such problems, the present inventors have found that the problems can be solved by using a copper compound, an iron compound and hydrogen sulfide, and have reached the present invention.
That is, the present invention
(1) A method for producing reduced glutathione, which comprises reducing oxidized glutathione in the presence of a copper compound, an iron compound and hydrogen sulfide,
Is to provide.

  The present invention is a simple and industrially advantageous production method with high yield and almost no by-products without using expensive reagents, special equipment, and the like.

Hereinafter, the present invention will be described in detail.
The origin of the oxidized glutathione which is the starting material of the present invention is not particularly limited, and it can be used in either a purified product or a crude product. Furthermore, since this reaction suitably proceeds in an aqueous solution, an aqueous solution containing oxidized glutathione can be used as it is.

The reduction is carried out in the presence of a copper compound, an iron compound and hydrogen sulfide.
Examples of the copper compound to be used include cuprous oxide and copper sulfate, and monovalent copper is preferable.
The copper compound is used in an amount of about 0.5 to 10 times mol, preferably about equimolar to 5 times mol with respect to oxidized glutathione. If it is less than this, the reaction does not proceed sufficiently, and even if it is used beyond this, it does not contribute to the improvement of the yield.

As the iron compound used, iron divalent and trivalent inorganic compounds are preferably used. For example, ferrous oxide, ferrous hydroxide, ferrous sulfate, ferric oxide, ferric hydroxide, ferric sulfate, etc. can be exemplified.
The iron compound is preferably used in an amount of 5 to 200 parts by weight, preferably 10 to 100 parts by weight, per 100 parts by weight of oxidized glutathione. If it is less than this, the reaction does not proceed sufficiently, and even if it is used beyond this, it does not contribute to the improvement of the yield.

The reaction is carried out by stirring oxidized glutathione, a copper compound, an iron compound and hydrogen sulfide in the presence of a solvent.
Hydrogen sulfide can be reacted by using a saturated solution of hydrogen sulfide or by directly introducing hydrogen sulfide gas into the solution.
The solvent used is not limited as long as it does not inhibit the reaction, but water is particularly preferable.
The reaction temperature is slightly elevated from room temperature, specifically about 10 to 50 ° C., and the reaction time is about 30 minutes to 10 hours, although depending on the reaction conditions. When the reaction time is long, the formation of by-products is not observed, but the produced reduced glutathione is oxidized and converted to oxidized glutathione, which is not preferable.

  After completion of the reaction, the target product can be easily isolated and purified by a known method, for example, by removing the precipitate and degassing the filtrate to obtain a copper salt.

Hereinafter, the present invention will be described in detail with reference to examples.
Example 1
To 400 ml of water, 4.66 g of cuprous oxide, 2.0 g of ferrous oxide and 4 g of oxidized glutathione were added, and hydrogen sulfide was gradually blown in at 35 ° C. with stirring.
The reaction was carried out for 2 hours while blowing hydrogen sulfide as it was, and analysis by high performance liquid chromatography revealed that the reduced glutathione was 9.04 mg / ml and the oxidized glutathione was 0.79 g / ml (conversion rate: 88.6%). . In addition, other peaks were not observed by high performance liquid chromatography.
After completion of the reaction, the reaction solution was filtered, and the resulting filtrate was stirred to degas the remaining hydrogen sulfide. Cuprous oxide was added to this solution, and reduced glutathione was isolated as a copper salt. Hereinafter, reduced glutathione was obtained by a conventional method.
Melting point: 184 ° C. Optical rotation: [α] _D = -16.42 ° (C = 4, H ₂ O)
The structure of this compound was identified by comparing the infrared absorption spectrum with that of a standard product.

Example 2
In Example 1, it implemented like Example 1 except having used ferric hydroxide 2.0g instead of the ferrous oxide.
When reacted for 1 hour and analyzed by high performance liquid chromatography, it was 7.26 mg / ml reduced glutathione and 1.94 g / ml oxidized glutathione (conversion rate 79.3%). In addition, other peaks were not observed by high performance liquid chromatography.

Example 3
In Example 1, it carried out like Example 1 except having used ferric sulfate 2.2g instead of ferrous oxide.
When reacted for 2 hours and analyzed by high performance liquid chromatography, it was 6.14 mg / ml reduced glutathione and 2.92 g / ml oxidized glutathione (conversion rate 68.5%). In addition, other peaks were not observed by high performance liquid chromatography.

Comparative Example 1
In Example 1, the reaction was carried out in the same manner as in Example 1 except that no cuprous oxide was added.
When the reaction was carried out for 2 hours and analyzed by high performance liquid chromatography, it was observed that the oxidized glutathione decreased, but it was not converted to reduced glutathione but decomposed into an unidentified compound. It was.

  As described above, the present invention is a simple and industrially advantageous method for reducing oxidized glutathione, in which the reaction proceeds with good yield even in an aqueous solution without the need for special equipment. In addition, reduced glutathione used in cosmetics and the like can be advantageously produced.

Claims (1)

  A method for producing reduced glutathione, which comprises reducing oxidized glutathione in the presence of a copper compound, an iron compound and hydrogen sulfide.