JP4288332B2 - Amino acid synthesis method - Google Patents

Description

In the present invention, graphite powder is used as a carbon source, metallic iron powder, or further iron sulfide powder is mixed with this, and ammonia as water and nitrogen source is supplied to the mixture by nitrogen gas. The present invention relates to a method for synthesizing amino acids by heating to the following temperatures.
Preferably, it is heated to a temperature of 500 ° C. or higher and 1000 ° C. or lower.
In the reference technique, the shock wave energy is energy generated when a flying object (flyer) collides with the reaction container. Varies greatly depending on container structure and flyer material. When a stainless steel fryer (diameter 30 mm, thickness 2 mm) is made to collide with a stainless steel reaction vessel (diameter 30 mm, length 30 mm) as in Reference Examples 1 and 2, the fryer collision speed is 0.8 km / second (impact The pressure is 16 Gp) or more, preferably 0.9 km / second (impact pressure 19 GPA). When the collision speed is increased, the reaction proceeds more, but when it is too large, the strength of the container cannot withstand the expansion of the vaporized component in the reaction container, and the sample cannot be collected due to destruction or scattering. When samples of the order of Examples 3 and 4 are included, the flyer speed of 1.1 km / sec (pressure 3 to 2.4 GPa) is the limit.

Conventionally, amino acids are easily obtained by hydrolyzing proteins with enzymes such as enzymes or hydrochloric acid. However, since all proteins are produced by living organisms, only L-form optically active amino acids can be obtained. In general, L-form amino acids are sufficient for pharmaceuticals, but D-form amino acids are required for reagents and special applications. For the production of individual D-form amino acids, the L-form of the same amino acid is racemized with an enzyme or a complex method (L-form-D-form mixture), and then only the D-form is separated and extracted. There is no known method for easily producing a so-called D-form of a protein-constituting 20 amino acids.
On the other hand, academically, such as research on the origin of life, S. L. Since Miller (1953) found that amino acids are produced in spark discharges in hydrogen, methane, ammonia, and water gases, the composition of the gases has been changed or replaced by spark discharges. A number of similar studies have been done using other energy sources such as ultraviolet light. It is a well-known fact that all amino acids produced by these abiotic synthesis methods are racemates in which the D form and the L form are mixed in an equal ratio. However, the synthesis method using carbon dioxide, carbon monoxide, or methane as the carbon source used in the previous research has a very low amino acid yield and is produced simultaneously with many other organic compounds. It cannot be an industrial production method for D-form amino acids.

S. L. Miller, Science 177 (1953) 528. Shi Huaibin, Shao Chunlin, Yu Zengliang, Nucl. Instr. and Meth. Phys. Res. B, VOL. 183, p369-373, 2001.10. Viva Origino JN: X0862A; ISSN: 0910-4003; CODN: VIORE6 VOL. 27 NO. 1: PAGE. 1; 1999.03.

As a related art of the prior art, in Non-Patent Document 2, three kinds of amino acids are obtained during reaction mixing by discharging in ammonia water using a graphite rod as an anode and a silver thread as a cathode in an Ar atmosphere. It was confirmed by HPLC and thin layer chromatographic analysis that the product was formed. At this time, the graphite anode is the only carbon source, and elements such as N, H, and O are aqueous ammonia, so Ser, Gly It was reported that 18 types of amino acids such as Ala were confirmed to be produced by the synthesis reaction of graphite and aqueous ammonia. In Non-patent Document 3, graphite is used as an important carbon source for the synthesis of organic compounds indispensable for the construction of living organisms such as carboxylic acids and amino acids, ammonia and water are used for this, and ultraviolet rays are used as an energy source. Used to report abiotic synthesis such as carboxylic acids and amino acids, D, L and β-alanine, Nm-glycine and glycine.
The above two non-patent documents are novel attempts in that solid graphite is used as a carbon source, but in either case, the conversion rate to an amino acid with respect to the carbon source or the like has not been clarified. The current situation is not big.

An object of the present invention is basically to provide a method for synthesizing novel amino acids using graphite powder as a carbon source, and particularly to provide a method for synthesizing a high amino acid conversion efficiency with respect to raw carbon. . Therefore, the present inventors have studied variously the coexistence component for improving the conversion efficiency, the selection method of the reaction energy supply method and the reaction raw material, and the supply method, and the graphite powder is a metal iron powder and / or an iron sulfide powder. And by supplying water and N feedstock to the mixture using nitrogen gas and applying thermal energy thereto, it is possible to synthesize racemic mixtures of various amino acids, particularly amino acids containing amino acids containing sulfur. It was possible to find out and solve the above problems.

The present invention is basically selected from the group consisting of (1) alanine, glutamine, glycine, isoleucine, phenylalanine, serine, threonine, aspartic acid, asparagine, glutamic acid, histidine, proline, tryptophan and lysine constituting the protein. in case Naruho of that amino acid, was supplied with nitrogen gas is non-oxidizing carrier gas Mizuoyobi ammonia in a mixture of graphite powder and metallic iron powder or iron sulfide powder as the carbon source, these 200 ° C. or higher An amino acid synthesis method comprising synthesizing an amino acid by heating to a temperature of 1000 ° C. or lower.

As an effect of the invention, the amino acids, can be converted graphite powder as a carbon source, also ammonia as an N source, and can be synthesized using water as the oxygen source, the amino acid in particular the carbon source at a high conversion rate, Can be mentioned.

The present invention will be described in more detail.
A) Graphite powder as a carbon source includes graphite, fullerene, carbon nanotube, and highly organic condensed aromatic organic carbon powder having C / H of 10/1 or more. The shape of the carbon source to be supplied is preferably a powder (particle size, 100 mesh or less) in order to increase the reaction efficiency.
B) As the metallic iron powder, for example, metallic iron (Wako Pure Chemicals, Iron Sponge, 99.9%) powder having reducing properties was used. Further, as the iron sulfide powder, for example, powdered iron sulfide (manufactured by CERAC, <100 mesh 99.9%) was used.
C) FIG. 1 is an example of a reaction apparatus. Nitrogen (N ₂ ) is used as a gas carrier gas, and this is passed through the aqueous ammonia solution in flask A and the water in flask B, and supplied to heating furnace F in which a silica boat containing graphite held in silica wool is placed. The extracted gas from the reaction path passes through the cooler C and the amino acids produced in the flask C are collected.
D) In order to synthesize amino acids by applying shock wave energy as described in the reference technology, graphite powder, nitrogen source feedstock, such as Cu ₃ N, liquid ammonia, etc., in particular ammonia gas, water and metallic iron powder and / or Alternatively, iron sulfide powder is sealed in a stainless steel container, and a fryer (Reference: Sekine, T., Shock wave chemical synthesis, European Journal of Solid State Inorganic Chemistry, Vol. 34, 823-833, 1997) is 0.88 km in the container. The reaction proceeds by colliding at a speed of / sec.

EXAMPLES Hereinafter, the present invention will be specifically described by way of examples. However, this is intended to make the present invention easier to understand, and it should be understood that the present invention is not construed as being limited thereto.
Analytical instrument: Hitachi, post-column OPA method, model TR-2004
Description of Example 1;
Graphite powder (Aldrich, powder <100 mesh, 99.99%) 5 mg and metallic iron powder (Wako Pure Chemical, Iron Sponge, 99.9%) 300 mg are placed on the silica boat of FIG. Both powders can be mixed and placed directly on a silica boat, but if silica wool is placed on the boat and both powders are sprinkled on it, the reaction is further accelerated. After flowing nitrogen gas through the system of FIG. 1 at about 600 mL / min and becoming steady, the system is heated in an electric furnace. The furnace temperature is preferably 200 ° C. or higher and about 500 to 1000 ° C. After reaching the same temperature, the water and the ammonia source are heated, and the cocks (1) to (7) are displayed so that the nitrogen gas of the carrier gas carries the water vapor and the ammonia gas . ) . The amino acid produced by reacting with graphite and excess water vapor are conveyed to the carrier gas, and are liquefied in the cooling pipe of FIG. The collected aqueous amino acid solution is freeze-dried or centrifuged (DC-800, manufactured by Daiwa Kagaku Co., Ltd.), and the solid component is dissolved again with 0.02N hydrochloric acid, followed by high performance liquid chromatography (Hitachi, post-column OPA method). FIG. 2 shows an example of the result of analysis by model TR3-2004).

From FIG. 2, ten kinds of protein-constituting amino acids synthesized at a furnace temperature of 500 ° C. were detected (NH ₄ in the figure is ammonia) . Since the detection method uses 0.02N hydrochloric acid as a solvent, asparagine and glutamine overlap with aspartic acid and glutamic acid, respectively, 12 types have been synthesized. The amino acids, cysteine and methionine not synthesized in this example are amino acids containing sulfur, and in this example, they are not produced because they do not contain sulfur as a raw material. Proline and tryptophan are not detected due to the low detection sensitivity in this analytical method (a total of 14 amino acids have been synthesized) .

In the same synthesis system as in Example 1, 5 mg of graphite powder (Aldrich, powder <100 mesh, 99.99%) and 300 mg of iron sulfide powder (CERAC, <100 mesh, 99.9%) were added as shown in FIG. Place on a silica boat. Although both powders can be mixed and placed directly on a silica boat, the reaction is further accelerated if silica wool is placed on the boat and both powders are sprinkled on it. After flowing nitrogen gas through the system of FIG. 1 at about 600 mL / min and becoming steady, the system is heated in an electric furnace. The temperature in the furnace is preferably 200 ° C. or more and about 500 to 1000 ° C. from the viewpoint of reaction rate.
Although a reaction at a higher temperature is possible, since the apparatus becomes larger as the temperature is higher, about 1000 ° C. is preferable from the viewpoint of economic cost. After reaching the same temperature, the water and the ammonia source are heated, and the cock is operated so that nitrogen gas conveys water vapor and ammonia gas. The amino acid produced by reacting with graphite and excess water vapor are conveyed to the carrier gas and liquefied in the cooling pipe of FIG.
The collected amino acid aqueous solution is freeze-dried (Tokyo Rika Kikai Co., Ltd., CVE-3100) or centrifugal dried (Daiwa Kagaku Co., Ltd., DC-800), and the solid component is dissolved again with 0.02N hydrochloric acid to be a high-speed liquid. When analyzed by chromatograph (OPA post column method), almost the same results as in FIG. 2 are obtained.
Reference example 1

Explain the case of synthesis using shock wave energy;
Copper nitride (Cu ₃ N) (high purity chemical, powder,> 99%) 800 mg 300 mg of the same metallic iron powder used in Example 1, 130 mg of water, and 8 mg of the same graphite powder as in Example 1 are made of stainless steel ( SUS # 394 ) Sealed inside a container (diameter 30 mm, length 30 mm) and a stainless steel fryer ( SUS # 304, reference Sekine, T., Shockwave chemical syntheis, European Journal of Solid State Inorganic Chemistry, 30 mm in diameter) 34, 823-833, 1997) was impacted at a speed of about 1 km / second to generate a shock wave. A single-stage gas gun was used for impact. After the impact, the container is taken out, and the outside of the dirty container is shaved by about 2 mm with a lathe and organic matter is removed with hydrogen peroxide. After cooling the entire container with liquid nitrogen, the diameter is 2 mm while maintaining the liquid nitrogen temperature. The water-soluble component produced inside the container was leached by squeezing with a drill of 1 mm and dipping in 70 mL of ultrapure water.
Since the solution in which the water-soluble component is dissolved contains a peptide in which amino acids are polymerized and dikedopiperazine, the solution is freeze-dried or centrifuged to solidify the dissolved component, and then hydrolyzed with 6N concentrated hydrochloric acid. , Adjusted to 0.02 N, and analyzed by a high performance liquid chromatograph (OPA post column method). The analysis results are shown in FIG. 16 kinds of protein-constituting amino acids similar to those in Example 1 were detected.
Reference example 2

The same copper nitride (Cu ₃ N) 800 mg as in Reference Example 1, 150 mg of the same metal iron powder as used in Example 1, 150 mg of the same iron sulfide (FeS) as used in Example 2, 130 mg of water and graphite powder 8 mg was enclosed in a stainless steel container (diameter 30 mm, length 30 mm), and a fryer with a thickness of 2 mm was collided with the container at a speed of about 1 km / second to generate a shock wave. A single-stage gas gun was used for impact. After the impact, the container is taken out, and the outside of the dirty container is shaved by about 2 mm with a lathe and organic matter is removed with hydrogen peroxide. After cooling the entire container with liquid nitrogen, the diameter is 2 mm while maintaining the liquid nitrogen temperature. The water-soluble component produced inside the container was leached by squeezing with a drill of 1 mm and dipping in 70 mL of ultrapure water.
Since the solution in which the water-soluble component is dissolved contains a peptide in which amino acids are polymerized and dikedopiperazine, the solution is freeze-dried or centrifuged to solidify the dissolved component, and then hydrolyzed with 6N concentrated hydrochloric acid. , Adjusted to 0.02 N, and analyzed by a high performance liquid chromatograph (OPA post column method). Fifteen types of protein-constituting amino acids including cysteine and methionine, which were almost the same as in Example 2, were detected.

The method for synthesizing amino acids of the present invention can provide various useful amino acids using readily available graphite as a carbon source, can be expected to design a practical device, and can be expected to be used industrially.

An example of the amino acid synthesis technique of the present invention is shown. Apparatus for implementing Examples 1 and 2 Analysis results of amino acid obtained by the synthesis method of Example 1 by high performance liquid chromatography Analysis results of amino acids obtained by the synthesis method of Reference Example 1 by high performance liquid chromatography

Claims (1)

Alanine constituting the protein, glutamine, glycine, isoleucine, phenylalanine, serine, threonine, aspartic acid, asparagine, glutamic acid, histidine, proline, in the case Naruho amino acid selected from the group consisting of tryptophan and lysine, as the carbon source Water and ammonia are supplied to a mixture of graphite powder and metallic iron powder or iron sulfide powder with nitrogen gas, which is a non-oxidizing carrier gas , and these are heated to a temperature of 200 ° C to 1000 ° C to synthesize amino acids. And a method for synthesizing amino acids.

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