JP3554821B2 - Method for synthesizing taurine from protein-containing substance using high-temperature high-pressure water - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for synthesizing taurine from a protein-containing substance for the purpose of recycling biological waste. Taurine (2-aminoethanesulfonic acid) is a substance having useful pharmacological actions such as antithrombotic action and cholesterol lowering action, and is also used as a food additive or as a raw material for a surfactant.
[0002]
[Prior art]
As a technique for decomposing and / or mineralizing a hardly decomposable organic substance, a treatment method using high-temperature and high-pressure water has attracted attention. Supercritical water at a critical point (374 ° C., 22 MPa) or higher is well mixed with a low-polarity organic compound and oxygen as an oxidizing agent, and since water itself has high reactivity, the oxidation of organic chemicals is And / or suitable for mineralization. On the other hand, subcritical water in a state lower than the critical point has a high ionic product, so that water itself has an acid-catalytic effect, or has a characteristic of low reactivity compared to supercritical water. BACKGROUND ART Research has been actively conducted for recovering and recycling chemical raw materials from polymer-based wastes such as plastics and chemical production residues by using as a reaction solvent.
[0003]
As an application example of the above-mentioned reaction using high-temperature and high-pressure water, organic acids such as lactic acid can be obtained by utilizing subcritical water as a reaction field from waste such as fish ash (visceral organs, bones and scales). Techniques for producing useful substances such as amino acids, long chain unsaturated fatty acids such as DHA and EPA have been reported. This technology involves a reaction in which proteins are hydrolyzed by subcritical water to produce amino acids and organic acids, and long-chain fatty acids such as DHA and EPA, which are naturally contained in fish, are extracted by subcritical water. This is to make use of the phenomenon that becomes easy. However, there is no report yet about further reaction to obtain another useful substance.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method capable of synthesizing highly useful taurine from biological waste containing proteins.
[0005]
[Means for Solving the Problems]
The present inventors studied the production reaction of amino acids by the above-mentioned reaction using high-temperature and high-pressure water from fishery processing wastes such as fish ilium, shrimp shells, and scallop scales. In addition, it has been found that taurine is produced. Then, since the production amount of taurine was larger than the production amount of other amino acids, the possibility that taurine was synthesized was examined. As a result, they have found a pathway for synthesizing taurine using amino acids as precursors, and have reached the present invention.
[0006]
That is, the first aspect of the present invention is a method for synthesizing taurine, comprising a step of reacting a biological substance containing a protein in high-temperature, high-pressure water.
A second aspect of the present invention is a method for synthesizing taurine, comprising a step of reacting a sulfur-containing amino acid in high-temperature, high-pressure water.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
The “biological substance containing a protein” used as a raw material in the present invention may be any substance containing an animal protein and / or a plant protein. However, for the original purpose of the present invention, it is preferable to use what is disposed of as waste. Examples of such waste include marine processed waste such as fish ilium, shrimp shells, scallops, and keratin-containing materials such as animal wings, hair, epidermis, and human hair.
[0008]
In the present invention, “high-temperature high-pressure water” means water in a supercritical region and a subcritical region. The water in the supercritical region (that is, supercritical water) means water in a specific range of temperature and pressure above the critical point (374 ° C., 22 MPa). Water in the subcritical region (ie, subcritical water) means water that is below the critical point and in the region near the critical point.
[0009]
In the present invention, “sulfur-containing amino acid” means a sulfur-containing amino acid represented by cysteine.
The reaction temperature in the method of the present invention is from 100 ° C to 400 ° C, preferably from 200 ° C to 350 ° C, more preferably from 250 ° C to 300 ° C.
The reaction pressure in the method of the present invention is from saturated vapor pressure to 50 MPa, preferably from saturated vapor pressure to 40 MPa, and more preferably from saturated vapor pressure to 30 MPa.
The reaction time in the method of the present invention is 1 minute to 3 hours, preferably 5 minutes to 60 minutes, more preferably 20 minutes to 40 minutes.
[0010]
The reaction in the method of the present invention is performed using 10 mL to 500 mL of water, preferably 50 mL to 100 mL of water per 1 g of the sample.
The process of the present invention can be carried out using a semi-batch device, a batch device or a flow tube type reactor.
After completion of the reaction, amino acids can be separated, recovered, and purified (for example, ion exchange) by a conventional method.
The amino acid and taurine contained in the reaction solution obtained by the reaction performed according to the method of the present invention can be analyzed using an automatic amino acid analyzer.
[0011]
Furthermore, in the method of the present invention, formic acid, hydrogen peroxide, an organic acid (for example, formic acid, acetic acid) or the like may be added as an oxidizing agent.
[0012]
Examples of the present invention are shown below, but they should not be construed as limiting the claims.
[0013]
【Example】
Example 1: High-temperature, high-pressure water reaction of scallops using a semi-batch apparatus Using a semi-batch reactor, 10 g of a sample (scallop scale) was charged into a reaction vessel, the pressure was kept constant at 30 MPa, and water was 40 mL / min. The temperature of the reaction vessel was raised while supplying the solution by using a pump. The reaction solution was sampled at regular intervals. Taurine and amino acids contained in the sampled reaction solution were analyzed using an automatic amino acid analyzer.
As a result, it was found that taurine (Tau) was contained in addition to amino acids such as glycine (Gly) and alanine (Ala). The results are shown in FIG. Taurine is produced in a relatively large amount after amino acids such as glycine and alanine derived from proteins contained in the raw material scale.
[0014]
Example 2: Verification of taurine synthesis pathway Since the production amount of taurine was larger than that of amino acids, the synthesis pathway of taurine was further examined. As a result, a taurine synthesis pathway using amino acids as a precursor was estimated. It is considered that cysteine is oxidized by high-temperature and high-pressure water, and a decarboxylation reaction occurs from cysteic acid via cysteic acid, thereby producing taurine (FIG. 2). This speculation indicates that the in vivo reaction may occur even in high-temperature and high-pressure water.
Further, it is considered that by adding an additive such as an oxidizing agent to the reaction to promote the oxidation reaction and the decarboxylation reaction, the amount of taurine generated can be improved.
Since the high-temperature and high-pressure reaction is suitable as an oxidation reaction field, the sulfur-containing amino acid is easily oxidized to cysteic acid which is considered to be a taurine precursor. Therefore, in this example, a high-temperature high-pressure water reaction was performed using cysteic acid as a raw material, and it was examined whether or not taurine was produced.
[0015]
An aqueous cysteic acid solution (concentration: 1 mmol / L, ie, 169 mg of cysteic acid in 1000 mL of water) was reacted at a temperature of 300 ° C. and a pressure of 30 MPa for 5 minutes using a flow tube type reactor. Note that cysteic acid was obtained by oxidizing cysteine using formic acid.
As a result of analyzing the collected sample, a peak of taurine considered to be generated from cysteic acid could be confirmed (FIG. 3).
Thus, it was confirmed that taurine could be produced from cysteine, which is a sulfur-containing amino acid, by the synthetic route shown in FIG.
[0016]
Example 3 Production of taurine from cysteine, which is a sulfur-containing amino acid at a high temperature and a high pressure in a water reaction, was confirmed using a batch reactor, and the production of taurine from keratin containing a large amount of cysteine was examined.
Using a batch reactor, 1 g of a keratin-containing substance (human hair) was reacted in 50 mL of water at a temperature of 250 ° C. and a saturated vapor pressure for 60 minutes.
FIG. 4 shows the results. Although human hair before the reaction did not contain any taurine, it was confirmed that taurine was formed after the reaction.
Furthermore, it has been found that by adding formic acid as an oxidizing agent, it is possible to increase the production amount of taurine.
[0017]
【The invention's effect】
According to the method of the present invention, protein-containing wastes (fishery processing wastes, keratin-containing wastes, etc.) that have been conventionally landfilled or used only as compost can be treated with high-temperature and high-pressure water to obtain usefulness. High taurine can be synthesized.
According to the method of the present invention, it is possible to recycle waste and thereby to generate new profits. Therefore, the present invention can be an excellent elemental technology for building a recycling-based society.
[Brief description of the drawings]
FIG. 1 is a view showing the results of reacting scallop scales under high-temperature and high-pressure water conditions using a semi-batch type apparatus.
FIG. 2 is a view showing a synthetic pathway of taurine using an amino acid as a precursor.
FIG. 3 is a view showing an HPLC chromatogram of a reaction solution obtained by reacting a cysteic acid aqueous solution under high-temperature and high-pressure water conditions using a flow tube type reactor.
FIG. 4 is a diagram showing the results of reacting human hair under high-temperature and high-pressure water conditions using a batch apparatus.

Claims (5)

A method for synthesizing taurine, comprising a step of reacting a protein containing cysteine selected from the group consisting of a keratin-containing substance, shrimp shell, and scallop scale in high-temperature, high-pressure water. The method of claim 1, wherein the keratin-containing material is selected from the group consisting of animal wings, hair, epidermis, and human hair . The method according to claim 1, wherein the high-temperature high-pressure water is water having a temperature of 100 ° C. to 400 ° C. and a saturated vapor pressure of 50 MPa. The method according to any one of claims 1 to 3, wherein an oxidizing agent is further used in the step. The method according to claim 4, wherein the oxidizing agent is formic acid, hydrogen peroxide, or an organic acid.

Images