JP2006160670A - Hair dye composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hair dye composition which uses an efficiently produced melanin precursor as an air oxidation type hair dye and has improved performances such as dyeability and safety. <P>SOLUTION: This hair dye composition contains one or more 5,6-dihydroxyindole derivatives represented by the general formula (2) (R<SP>1</SP>and R<SP>2</SP>are each H, carboxy or a straight chain or branched 1 to 4C alkyl) and produced by a step (step (I)) for adjusting an aqueous solution containing ≥0.01 wt.% of a 5,6-dihydroxyindoline derivative represented by the general formula (1) to pH 5 to 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hair dye composition that contains a melanin precursor that is efficiently produced using an enzyme and is excellent in dyeability, stability, and safety, and more particularly to a one-component air oxidation hair dye composition. .

  Melanin precursors such as 5,6-dihydroxyindole and 5,6-dihydroxyindoline are known to be converted into melanin pigments by oxygen in the air, and are used for air oxidation hair dyes using this. Has been.

  As a method for obtaining 5,6-dihydroxyindole and 5,6-dihydroxyindoline, production examples by chemical synthesis reaction are known (Non-patent Document 1 and Patent Document 1). However, there are problems such as a decrease in yield due to side reactions, time burden due to isolation of target reactive organisms, high costs, and concerns about the effects of residual solvent. Moreover, the manufacturing method using laccase is known as a manufacturing technique of the melanin precursor by an enzyme reaction (patent document 2). However, there are problems such as the yield of the product such as melanin produced by oxidative polymerization, and a recovery method, and the laccase used needs to be purified from plants such as lacquer.

  On the other hand, in terms of performance as a hair dye, for example, 5,6-dihydroxyindoline derivatives such as 5,6-dihydroxyindoline and 5,6-dihydroxyindoline-2-carboxylic acid are crystals, bromic acid, hydrochloride and the like. Although it is relatively stable in a salt state, there is a problem that even in an anaerobic state in which no oxygen is present, the stability is low in an aqueous solution state, and long-term storage is difficult. Therefore, in order to use the hair dye in a more stable state, it has been necessary to convert the 5,6-dihydroxyindoline derivative into a 5,6-dihydroxyindole derivative. However, for example, when trying to convert 5,6-dihydroxyindoline-2-carboxylic acid to 5,6-dihydroxyindole, 5,6-dihydroxyindole-2-carboxylic acid, etc. This requires a complicated process of protecting the hydroxy group and is not economical. In addition, the oxidation reaction with an enzyme causes problems such as generation of melanin, resulting in a low yield, and necessity of fractionation with melanin after production. Therefore, a milder conversion method has been demanded.

HELVETICA CHIMICA ACTA, 1968, 51, 1476 EP 1530229 Specification Japanese Patent Laid-Open No. 2002-291496

  Therefore, the present invention provides a hair dye excellent in dyeability, stability and the like by efficiently producing 5,6-dihydroxyindole from 5,6-dihydroxyindoline or a derivative thereof, and blending it in the hair dye. An object is to provide a composition.

  The present inventors have found that a hair dye containing a melanin precursor produced from a 5,6-dihydroxyindoline derivative using a specific method exhibits stable and excellent performance.

  That is, the present invention relates to a general formula produced by a step of adjusting an aqueous solution containing 0.01% by weight or more of a 5,6-dihydroxyindoline derivative represented by the general formula (1) to a pH of 5 to 11 [step (I)]. The present invention provides a hair dye composition containing one or more 5,6-dihydroxyindole derivatives represented by (2).

[Wherein, R ¹ and R ² represent a hydrogen atom, a carboxy group, or a linear or branched alkyl group having 1 to 4 carbon atoms. ]

  The hair dye composition of the present invention can be produced efficiently and is excellent in dyeability, stability and the like.

  The 5,6-dihydroxyindole derivative (2) used in the present invention is produced by a method including the step (I).

-Process (I)-
In this step, an aqueous solution containing 0.01% by weight or more of a 5,6-dihydroxyindoline derivative (1) (hereinafter referred to as “indoline derivative (1)”) is adjusted to a pH of 5 to 11, thereby producing a 5,6-dihydroxyindole derivative. (2) A step of converting to (hereinafter referred to as “indole derivative (2)”).

  The indoline derivative (1) used in the present invention is produced by chemical synthesis (for example, 5,6-dihydroxyindoline-2-carboxylic acid produced by the method described in Non-Patent Document 1, and the method described in Patent Document 1). 5,6-dihydroxyindoline produced by the method described above, tyrosine or a derivative thereof produced using an enzyme (for example, an indoline derivative produced by the method described in Patent Document 2), or an enzyme reaction Any of those combined with a chemical synthesis method (for example, an acetyl compound shown in Example 1 of Patent Document 2) can be used. Among these, since the reaction can be controlled by a series of operations and it is economical, it is preferable to use an indoline derivative produced using an enzymatic reaction.

When an enzyme reaction is used, tyrosine or a derivative thereof used as a starting material includes (1) D-form or L-form tyrosine, (2) D-form or L-form dopa [DOPA; 3- (3,4 -Dihydroxyphenyl) alanine], (3) Dopamine (3,4-dihydroxyphenethylamine), (4) tyrosine lower (C _1-4 ) alkyl ester, (5) DOPA lower (C _1-4 ) alkyl Examples thereof include ester, (6) N-alkoxy (eg, acetoxy) or N-alkyl (eg, ethyl) DOPA or tyrosine. Moreover, these isomers may be sufficient. Among them, L-tyrosine and L-DOPA are preferable in that a natural melanin precursor can be obtained, and L-DOPA is more preferable in terms of affinity for an enzyme. These tyrosine or derivatives thereof can be used alone or in combination of two or more. Examples of the enzyme include those having catechol oxidase activity, such as catechol oxidase having monophenol oxidase activity, monophenol oxidase, diphenol oxidase, o-diphenolase, tyrosinase, etc .; laccase having polyphenol oxidase activity, peroxidase, etc. . Among these, it is preferable to use tyrosinase from the viewpoint that a natural melanin precursor can be efficiently produced because of its high affinity for L-DOPA. When tyrosine is used as the substrate compound, tyrosinase is used. Catechol oxidase may be an enzyme derived from any organism, but tyrosinase derived from filamentous fungi is particularly preferable because of its high expression efficiency and stability in the host cell. Examples of such filamentous fungi include the genus Aspergillus, the genus Neurospora, the genus Rhizomucor, the genus Trichoderma and the genus Penicillium. Among them, tyrosinase of Aspergillus genus fungus is preferable because it is relatively stable against heat and has been confirmed to be safe. Specifically, melB gene of Aspergillus oryzae 2002-191366), melD gene (JP 2004-201545) or melO gene (Molecular cloning and nucleotide sequence of the protyrosinase gene, melO, from Aspergillus oryzae and expression of the gene in yeast cells.Biochim Biophys Acta. And tyrosinase encoded by 1995 Mar 14; 1261 (1): 151-154).

  The indoline derivative (1) is preferably an indoline derivative (1) produced by reacting a cell or enzyme having catechol oxidase activity with tyrosine or a derivative thereof as a starting material, from the amount of by-products. In particular, 5,6-dihydroxyindoline-2-carboxylic acid or 5,6-dihydroxyindoline produced by allowing a cell or enzyme having catechol oxidase activity to act using a DOPA derivative as a starting material is preferred. Most preferred is 5,6-dihydroxyindoline-2-carboxylic acid produced by allowing a cell or enzyme having catechol oxidase activity to act on DOPA as a starting material.

  What is obtained as a temporary intermediate of the reaction to produce 5,6-dihydroxyindoline-2-carboxylic acid from tyrosine or DOPA by tyrosinase or the like is dopachrome, but the substance that can be substantially taken out as a product is its reduced state. 5,6-dihydroxyindoline-2-carboxylic acid (leucodopa chrome). Therefore, in the present invention, dopachrome and 5,6-dihydroxyindoline-2-carboxylic acid are treated as 5,6-dihydroxyindoline derivatives without strictly distinguishing them. Similarly, 5,6-dihydroxyindoline is treated synonymously with indolinequinone. In fact, in the quantification method used in the present invention, dopachrome is quantified as 5,6-dihydroxyindoline-2-carboxylic acid by adding a reducing agent.

  Note that 5,6-dihydroxyindoles oxidized one step from dopachrome are not changed to dopachrome by a usual reducing agent such as ascorbic acid. In addition, this compound is also a monomer for initiating polymerization for melanin formation, and when it is attempted to produce 5,6-dihydroxyindoles by direct oxidation by enzymes or cells, melanin production occurs, resulting in a low yield. This causes disadvantages such as the need for subsequent fractionation with melanin.

  The concentration of the aqueous solution of the indoline derivative (1) to be treated in the step (I) is 0.01% by weight or more from the viewpoint of efficient treatment and obtaining a stable indole derivative (2). It is preferably 0.2% by weight or more and 50% by weight or less. The indole derivative (1) is preferably a single substance, but may be a mixture of melanin precursors in various oxidation states.

  The pH adjustment range in the step (I) is preferably pH 5 to 11, more preferably pH 5 to 10, and particularly preferably pH 6 to 9. Conversion to an indole derivative proceeds efficiently in this range. On the other hand, precipitation occurs in strong acidity, and oxidative polymerization is accelerated and melanin is generated in strong alkalinity.

  The treatment is preferably performed under anaerobic conditions, but the presence of oxygen is not necessarily denied as long as a sufficient yield is obtained in step (I).

  Here, the kind of the indole derivative (2) to be obtained can be adjusted by adjusting the pH to the neutral to weakly acidic side or the alkali side. For example, when 5,6-dihydroxyindoline-2-carboxylic acid is used as the indoline derivative (1), conversion to 5,6-dihydroxyindole is likely to occur if the pH is 5 or more and less than 8, and the pH is 8 or more and 11 or less. For example, conversion to 5,6-dihydroxyindole-2-carboxylic acid is likely to occur. That is, 5,6-dihydroxyindole is produced in the neutral to acidic region, and 5,6-dihydroxyindole-2-carboxylic acid is efficiently produced in the alkaline region. Further, when 5,6-dihydroxyindoline is used as the indoline derivative (1), only 5,6-dihydroxyindole is mainly produced in the pH range of 5-11. From the viewpoint of efficiency (speed, yield, etc.), pH 7 to 10 is preferable.

  The treatment temperature in the step (I) is preferably 5 to 40 ° C., particularly preferably 15 to 30 ° C. The treatment time may be maintained using the time for the indoline derivative (1) to change as an index. Although depending on the temperature, if it is 30 minutes or longer, the sinindole derivative (2) can be obtained relatively stably. After the treatment in step (I), it may be left for a long period of time, for example, for one week or longer as long as it is in an oxygen-blocked state.

  In the present invention, in the step (I) pH adjustment, further to the aqueous solution of indoline derivative (1) (i) water-soluble organic solvent, (ii) inorganic salt, (iii) buffer, (iv) antioxidant By using one or more of these components in combination, the indoline derivative (1) can be more efficiently converted to the indole derivative (2).

  (i) As the water-soluble organic solvent, an organic solvent having compatibility of 10% by weight or more in water (dissolving 10g or more in 90g of water) can be used. For example, alcohols such as methanol, ethanol, benzyl alcohol, etc .; polyethylene Polyhydric alcohols such as glycol and glycerol; Ketones such as acetone; Organic acids such as lactic acid and citric acid; Fatty acids such as acetic acid and propionic acid; Alkylamines; Alkanolamines such as monoethanolamine can be used . In particular, ethanol and acetone are preferable.

  In particular, the addition of alcohols, polyhydric alcohols, ketones, organic acids or fatty acids can facilitate the conversion of 5,6-dihydroxyindoline-2-carboxylic acid to 5,6-dihydroxyindole. . For example, the addition of 50% by weight of ethanol promotes the conversion of 5,6-dihydroxyindoline-2-carboxylic acid to 5,6-dihydroxyindole. Alkylamines or alkanolamines can also promote the conversion of 5,6-dihydroxyindoline-2-carboxylic acid to 5,6-dihydroxyindole-2-carboxylic acid. For example, it becomes possible to selectively convert 5,6-dihydroxyindoline-2-carboxylic acid to 5,6-dihydroxyindole-2-carboxylic acid by adding 5 to 50% by weight of monoethanolamine. .

  The aqueous organic solvent is preferably added to the reaction solution so as to have a concentration of 70% by weight or less, more preferably 5 to 70% by weight, particularly about 30 to 60% by weight. Even if the amount of the solvent added is increased, there is no particular problem. On the contrary, the conversion rate is increased and the produced melanin can be removed, but in the above range, the indole derivative (2 ) Ratio and the post-processing can be performed safely.

  (ii) As the inorganic salt, an alkali metal salt, alkaline earth metal salt or copper (II) salt of an acid selected from hydrochloric acid, nitric acid, sulfuric acid and carbonic acid can be used. Of these, copper (II) salt can promote the conversion of 5,6-dihydroxyindoline-2-carboxylic acid to 5,6-dihydroxyindole-2-carboxylic acid, and other than copper (II) salt The inorganic salt of can promote the conversion of 5,6-dihydroxyindoline-2-carboxylic acid to 5,6-dihydroxyindole. The inorganic salt concentration in the reaction solution is preferably 40% by weight or less, more preferably 0.1 to 20% by weight, and particularly preferably 1 to 5% by weight from the viewpoint of conversion efficiency and prevention of precipitation of salt and melanin. Further, when using a copper (II) salt, 0.1 to 20 mM, particularly 5 to 10 mM is preferable. For example, by storing for about 10 to 30 minutes, 5,6-dihydroxyindoline-2-carboxylic acid 5,6- Conversion to dihydroxyindole-2-carboxylic acid is facilitated.

  (iii) Examples of the buffer include a phosphate buffer. Examples of the phosphate buffer include sodium phosphate buffer, potassium phosphate buffer, citrate-sodium phosphate buffer, and tris-phosphate buffer. Treatment with a phosphate buffer can facilitate the conversion of 5,6-dihydroxyindoline-2-carboxylic acid to 5,6-dihydroxyindole-2-carboxylic acid.

  (iv) As the antioxidant, ascorbic acid, sodium ascorbate, sodium sulfite and the like can be used. When 2.5% by weight of sodium ascorbate is added to the reaction solution, 5,6-dihydroxyindoline-2-carboxylic acid is changed to 5, The conversion rate to 6-dihydroxyindole is accelerated.

  When the indole derivative obtained as described above is used as a raw material for the hair dye composition, it can be concentrated by a concentration step, for example, a reverse osmosis curtain. The concentration step by the reverse osmosis curtain can be performed using, for example, a crossflow type reverse osmosis concentration device (manufactured by Nitto Denko Matex Co., Ltd.) used for producing pure water from seawater.

  In the present invention, when an indoline derivative produced using an enzyme or a cell is used, as a step other than step (I), operations such as deproteinization, concentration or desalting, purification, and drying are performed by a conventional method. Can do. In particular, concentration using a reverse osmosis membrane is preferable from the viewpoint of operability as a concentration operation, and ultrafiltration using a membrane having a molecular weight of about 10,000 is preferable in order to remove proteins mixed in by the process. It is also effective to remove the high-molecular melanin produced when ultrafiltration is performed after step (I).

-Hair dye composition-
By blending the indole derivative (2) obtained as described above into a hair dye, a simple one-component air-oxidized hair dye that can be taken out of the container and left on the hair for a while is obtained. It becomes possible, and dyed white hair can be dyed with the natural shade of melanin.

  The content of the indole derivative (2) in the hair dye composition of the present invention is preferably 0.01 to 10% by weight, more preferably 0.05 to 5% by weight, and particularly preferably 0.1 to 1% by weight from the viewpoint of hair dyeing performance. Here, the content of the indole derivative (2) can be adjusted by the method of using the hair dye. For example, when the hair is dyed deeply (black) to the target level with a single hair dye, 0.5 to 1 weight is used. % Is preferable, and in the case of a hair dye that does not make gray hair stand out by repeatedly dyeing hair, 0.1 to 0.4% by weight is preferable. In addition, if the content is 0.01% by weight or more, hair can be dyed although it is very little, so it can be used for hair dyes that are handled by hand, dyes for color rinses, hair cosmetics, etc. .

  The pH of the hair dye composition of the present invention is preferably adjusted to 6 to 11, particularly 7 to 10.5. For pH adjustment, for example, an alkali agent such as sodium hydroxide, potassium hydroxide, ammonia, guanidine, alkanolamine, basic amino acid, carbonate or the like is used. Examples of alkanolamines include monoethanolamine. Specific examples of basic amino acids include arginine, lysine, histidine and the like. Specific examples of carbonates include sodium carbonate, potassium carbonate, guanidine carbonate, and sodium bicarbonate. Is mentioned. In combination with an alkali agent, inorganic or organic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, citric acid, and lactic acid can be appropriately used. Two or more pH adjusters may be used in combination, and the content thereof is preferably 0.01 to 20% by weight, particularly preferably 0.1 to 10% by weight, based on the total composition.

  As a complementary component of the hair dye, a water-compatible organic solvent can be contained. Examples of water-compatible organic solvents include: lower alcohols such as ethanol and propanol; glycols such as ethylene glycol and propylene glycol; ethylene glycol monoethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether; diethylene glycol mono Examples thereof include carbitols such as ethyl ether and diethylene glycol monobutyl ether; benzyloxyethanol, benzyl alcohol and the like. Among these, the above lower alcohols and glycols are preferable. Two or more types of water-compatible organic solvents can be used in combination. In particular, when benzyloxyethanol or benzyl alcohol is used, it is preferably used in combination with other solvents, particularly lower alcohols or glycols. The content of the water-compatible organic solvent is preferably 5 to 50% by weight of the total composition, more preferably 10 to 40% by weight, and particularly preferably 15 to 30% by weight from the viewpoint of dyeability.

  The hair dye composition of the present invention can take the form of cream, gel, lotion, foam and the like by adjusting the viscosity by adding a thickener. Examples of the thickener include hydroxyethyl cellulose, ether of hydroxyethyl cellulose and glycidyl trimethyl ammonium chloride, cellulose derivatives such as methyl cellulose and carboxymethyl cellulose; natural gums such as xanthan gum and guar gum; polyvinyl pyrrolidone, cross-linked polyacrylic acid or a salt thereof, Examples thereof include synthetic polymers such as polyacrylic acid or a salt thereof and polyacrylamide. The kind and amount to be blended can be determined by the target viscosity, and the viscosity is preferably 100 to 50000 mPa · s. When the hair dye composition of the present invention does not thicken, a light feeling of use can be obtained, but by adding a thickener to increase the viscosity, the dyeing power is not impaired and there is no worry of dripping. Can be used.

  The hair dye composition of the present invention can contain a nonionic surfactant as a foaming agent and / or a homogenizing agent. Nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether and polyoxyethylene stearyl ether; polyoxyethylene alkyl phenyl ethers such as polyoxyethylene nonyl phenyl ether and polyoxyethylene octyl phenyl ether; Examples thereof include oxyethylene sorbitan fatty acid ester, fatty acid alkylolamide, polyoxyethylene-sec-tetradecyl ether and the like. The content of the nonionic surfactant is preferably 0.01 to 30% by weight, particularly preferably 0.1 to 10% by weight.

  Furthermore, it is desirable to add an antioxidant to the hair dye composition of the present invention in order to ensure the stability of the hair dye. Antioxidants include ascorbic acid, sodium ascorbate, ascorbic acid esters such as ascorbic acid esters, inorganic salts such as sodium sulfite, cysteine derivatives such as cysteine and N-acetylcysteine, rosemary extract, tea extract and other antioxidants. And plant extract, vitamins such as tocopherol and tocopherol acetate, and radical trapping agents such as BHT. Of these, ascorbic acids are preferable, and sodium ascorbate is particularly preferable in consideration of the use pH. In addition, chelating agents such as EDTA or a salt thereof, 1-hydroxyethane-1,1-diphosphonic acid or a salt thereof can be used as a component for improving stability.

  In addition to the above components, the hair dye composition of the present invention includes components used in ordinary hair dyes, such as surfactants, stabilizers, buffers, fragrances, feel improvers, chelating agents other than those described above, Solubilizers, preservatives, and the like can be appropriately blended depending on the purpose.

  A preferred form of the hair dye composition of the present invention includes a gradual dyeing hair dye that is used repeatedly. An aerosol form is preferred.

In order to make the hair dye composition of the present invention an aerosol type, a pressure-resistant container (such as an aerosol can) may be filled with a propellant together with the hair dye composition. As the propellant, compressed gas, liquefied gas, etc. generally used for aerosol products can be used. As compressed gas, nitrogen gas, carbon dioxide gas, argon gas, etc. are used. As liquefied gas, liquefied petroleum gas, lower saturated hydrocarbons are used. And dimethyl ether. Two or more of these propellants can be used in combination, and in order to obtain an appropriate injection speed, it is preferable to contain 1 to 20% by weight, particularly 3 to 15% by weight in the total composition. Moreover, it is preferable to adjust so that the internal pressure of the aerosol can after filling may be 3 to 5 kg / cm ² G (25 ° C.).

<Method for quantifying indoline derivative and indole derivative (melanin precursor)>
The melanin precursor was detected and quantified under the following conditions using HPLC Alliance2695-2996 manufactured by Waters.
For separation of the components, an imtakt reverse phase column Unison UK-C18 (4.6 × 150 mm) was used, and 1.5% phosphoric acid solution (A solution) and 99.9% methanol (B solution) were used as the mobile phase. The gradient was set so that the B liquid was 0% at the initial stage and 50% after 5 minutes. The flow rate was 1.0 mL / min.
For the sample to be injected, add 10 μL of sample to 100 μL of 20 mM sodium dithionite (Na ₂ S ₂ O ₄ ) and 890 μL of 1.5% phosphoric acid (H ₃ PO ₄ ) solution, and use a 0.45 μm filter. Prepared by filtration. 20 μL of this was injected into the column and measured.
The detection of dopa was monitored by the absorbance at 280 nm, which is the maximum absorption wavelength. Dopachrome is quantified as reduced leucodopachrome (5,6-dihydroxyindoline-2-carboxylic acid) under the above measurement conditions. 5,6-dihydroxyindole was quantified based on a standard substance (alkali hydrolyzate of 5,6-diacetoxyindole), and 5,6-dihydroxyindole-2-carboxylic acid was compared with the peak area at 280 nm. The maximum absorption wavelength of 5,6-dihydroxyindole is 300 nm, and the maximum absorption wavelength of 5,6-dihydroxyindolecarboxylic acid is 320 nm.
In addition, the abundance ratio of the melanin precursor shown below is based on the area ratio of the absorbance at 280 nm by HPLC analysis.

Production Example 1
<Conversion of 5,6-dihydroxyindoline to 5,6-dihydroxyindole>
To 0.1 g of 5,6-dihydroxyindoline / bromate, 100 g of 0.25 M phosphate buffer was added to adjust the pH to 7 (to adjust the pH to neutral so that the pH does not become acidic with bromic acid).
The change over time of the composition of the melanin precursor was examined by the above-described quantitative method (HPLC) while stirring in an open system at room temperature from the start to 90 minutes. After 30 minutes, more than 90% of 5,6-dihydroxyindoline became 5,6-dihydroxyindole, and after 60 minutes almost all became 5,6-dihydroxyindole. From 60 minutes to 90 minutes, the amount did not change and was relatively stable.

Production Example 2
<Conversion of 5,6-dihydroxyindoline-2-carboxylic acid to 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid>
100 g of 0.25 M phosphate buffer was added to 0.1 g of 5,6-dihydroxyindoline-2-carboxylic acid / hydrochloride to adjust to pH 7 (pH adjusted to neutral so that the pH would not become acidic with hydrochloric acid) For).
The change over time of the composition of the melanin precursor was examined by the above-described quantitative method (HPLC) while stirring in an open system at room temperature from the start to 90 minutes. After 30 minutes, about 70% of 5,6-dihydroxyindoline-2-carboxylic acid became 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid, and the ratio was about 9: 1. . After 60 minutes, 5,6-dihydroxyindoline-2-carboxylic acid almost disappeared to about 95% 5,6-dihydroxyindole and 5% 5,6-dihydroxyindole-2-carboxylic acid. From 60 minutes to 90 minutes, the amount remained unchanged and relatively stable.

Production Example 3
<Conversion of 5,6-dihydroxyindoline-2-carboxylic acid to 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid>
The pH was adjusted to 10 by adding 100 g of water and aqueous ammonia to 0.1 g of 5,6-dihydroxyindoline-2-carboxylic acid / hydrochloride.
The change over time of the composition of the melanin precursor was examined by the above-described quantitative method (HPLC) while stirring in an open system at room temperature from the start to 90 minutes. After 30 minutes, most of the 5,6-dihydroxyindoline-2-carboxylic acid has disappeared to produce 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid, the ratio being about 4: 6. After 60 minutes, the ratio was 3: 7.

Production Example 4
<Production of indoline derivatives by tyrosinase, separation from enzymes, conversion reaction to indole derivatives>
About 10 mM dopachrome was produced from about 20 mM L-DOPA by tyrosinase activity in which the melB gene of Aspergillus oryzae (JP 2002-191366 A) was expressed in Escherichia coli (0.1 M phosphate buffer pH 6, Room temperature, 30 minutes, reaction solution 10 mL). After removing the enzyme by ultrafiltration, the pH was adjusted to 7.5 with sodium hydroxide, and the change over time of the composition of the melanin precursor including dopachrome was examined by the above quantitative method (HPLC) in an open system. . As with 5,6-dihydroxyindoline-2-carboxylic acid, by 60 minutes, the original peak disappeared, about 90% 5,6-dihydroxyindole and about 10% 5,6-dihydroxyindole-2- It became carboxylic acid.

Example 1
<Preparation of hair dye composition>
(1) Preparation of Melanin Precursor Solution The aqueous solutions obtained in Production Examples 1 to 4 were concentrated by the following reverse osmosis curtain method to prepare 1 wt% melanin precursor solutions 1 to 4.
As the concentrating device, a cross flow type reverse osmosis concentrating device (manufactured by Nitto Denko Matex Co., Ltd.) used for producing pure water from seawater was used. This device circulates the solution between the closed tank containing the melanin precursor solution and the reverse osmosis concentration module NTR7410-HG-S4F, and the pure water generated by the reverse osmosis concentration module passes through this module. Led to water tank. As pure water is produced, the melanin precursor is concentrated in the tank. Circulation was performed by a pump at a pressure of 2 MPa.

(2) Preparation of hair dye composition
1 to 430 g of melanin precursor solution obtained in (1) (about 0.3 g as melanin precursor), 90 g of softanol, 0.2 g of xanthan gum, 0.5 g of ammonia water, 10 g of ethanol, and the remaining water and the remaining water. 100 g was prepared. The preparation was performed under anaerobic conditions in order to prevent oxygen contamination. This was used as an undiluted solution and filled into an aerosol container together with a propellant (LPG) (undiluted solution: propellant = 90: 10, weight ratio), which were products 1 to 4 of the present invention.

(3) Hair dye test (evaluation by colorimeter)
1 g of the product 2 of the present invention was applied to 1 g of gray hair toss and dyed at 30 ° C. for 15 minutes. Thereafter, it was washed with water, shampooed, hair rinsed, and then dried. This operation was repeated 5 times every 7 days. The dyed tress was measured with a spectrocolorimeter (CM-2002 manufactured by Minolta Co.) and evaluated by the color difference (ΔE) calculated according to the following formula.

ΔE = {(L ₁ −L ₀ ) ² + (a ₁ −a ₀ ) ² + (b ₁ −b ₀ ) ² } ^1/2
(L ₀ , a ₀ , b ₀ ): Colorimetric value of the white hair tress before dyeing (L ₁ , a ₁ , b ₁ ): Colorimetric value of the white hair tress after dyeing 15, 3rd: 28, 5th: 38, gradually becoming black.

(4) Stability The quantified value of the main peak by HPLC after the products 2 and 3 of the present invention were stored at 40 ° C. for 2 weeks hardly changed, and high stability was confirmed.

Example 2 Hair dye composition (foam type)
Dye consisting of 5 g of the melanin precursor solution obtained in Production Examples 1 to 4 (including about 0.05 g as the melanin precursor), 0.5 g of softanol, 0.1 g of xanthan gum, 0.4 g of cationized cellulose, 10 g of ethanol and the remaining water. 100 g of hair was prepared. The preparation was performed under anaerobic conditions in order to prevent oxygen contamination. This was used as a stock solution, and each was filled in an aerosol container together with a propellant (LPG) (stock solution: propellant = 90: 10, weight ratio).

Claims (4)

It is represented by the general formula (2) produced by the step (step (I)) of adjusting an aqueous solution containing 0.01% by weight or more of the 5,6-dihydroxyindoline derivative represented by the general formula (1) to pH 5-11. A hair dye composition containing one or more 5,6-dihydroxyindole derivatives.
[Wherein, R ¹ and R ² represent a hydrogen atom, a carboxy group, or a linear or branched alkyl group having 1 to 4 carbon atoms. ]   The hair dye according to claim 1, wherein step (I) is performed in an aqueous solution to which one or more compounds selected from water-soluble organic solvents, inorganic salts, buffers and antioxidants are added. Composition.   5,6-dihydroxyindoline derivative (1) is a 5,6-dihydroxyindoline-2-carboxylic acid produced by reacting a cell or enzyme having catechol oxidase activity with tyrosine or a derivative thereof as a starting material, or 5, The hair dye composition according to claim 1 or 2, which is 6-dihydroxyindoline.   The hair dye composition according to any one of claims 1 to 3, which is an air oxidation hair dye composition.