JPH08134090A - Galactosyl kojic acid, its production and tyrosinase-inhibiting agent containing the same - Google Patents

Abstract

PURPOSE: To obtain a new galactosyl kojic acid having a tyrosinase-inhibiting action and a melamine production-inhibiting action and useful as an oxidation and black coloration-preventing agent for foods, a beautifully whitening agent for cosmetics, etc., by reacting kojic acid with lactose in the presence of an enzyme. CONSTITUTION: This new galactosyl kojic acid represented by formula I resolves problems such as solubility in water and stability, has a tyrosinase-inhibiting action and a melamine production-inhibiting action, and is useful as an oxidation and black coloration-preventing agent, a beautifully whitening agent for cosmetics, etc. The compound is obtained as galactopyranosyl-β-0-2-methyl-5- hydroxy-γ-pyrone by reacting kojic acid of formula II with lactose in the presence of an immobilized enzyme in a 0.1M phosphoric acid buffer solution (pH6.0) at 40 deg.C for 12hr. The immobilized enzyme is obtained by immobilizing β- galactosidase on a ceramic carrier with glutaraldehyde.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a novel galactosyl kojic acid having tyrosinase inhibition,
It is used in the fields of food and cosmetics. .

[0002]

BACKGROUND OF THE INVENTION Kojic acid is isolated from a culture solution of Aspergillus niger, which gives color and flavor to miso, soy sauce, sake and the like.
Functions such as chelate forming function with metals such as iron, antioxidant function, ultraviolet absorbing function, antibacterial property, and whitening effect have been clarified. Kojic acid has an inhibitory effect on tyrosinase which catalyzes the oxidation of tyrosine and doper,
It is used as an anti-blackening agent in foods by utilizing this action, and also as a whitening agent in cosmetics because it has a remarkable inhibitory action on melanin production.

However, kojic acid has problems such as relatively low solubility (solubility in water of 8%) and low stability, and it is sufficiently satisfactory as an antioxidant for antioxidants and blackening in foods and a whitening agent for cosmetics. is not.

[0004]

An object of the present invention is to solve the problems such as solubility and stability of kojic acid in water, and to provide a novel chemical substance having an inhibitory effect on tyrosinase.

[0005]

The inventors of the present invention have found that this problem can be ameliorated by additionally binding lactose to kojic acid, and completed the present invention. That is, the present invention relates to a novel compound galactosyl kojic acid which solves problems such as solubility and stability of kojic acid and has an inhibitory effect on tyrosinase. Galactosyl kojic acid, which is the object of the present invention, is novel and is a novel substance represented by the following formula (I).

Suitable salts of the target compound (I) include, for example, alkali metal salts (eg sodium salt, potassium salt, cesium salt etc.), alkaline earth metal salts (eg calcium salt, magnesium salt etc.) and the like. Metal salts, ammonium salts, salts with organic bases (for example, trimethylamine salt, triethylamine salt, pyridine salt, picoline salt, ethanolamine salt, triethanolamine salt, dicyclohexylamine salt, N, N′-dibenzylethylenediamine salt, etc. ), Salts with amino acids (eg, arginine salts,
Aspartate, glutamate, etc.) and the like.

The object compound (I) or a salt thereof can be produced by the method represented by the following reaction formula.

The object compound (I) or its salt can be prepared by reacting the compound (II) with the compound (III) or its salt. When compound (II) and compound (III) are natural products, compound (II) is preferably added to compound (I) in the presence of β-galactosidase.
It can be produced by reacting with II) or a salt thereof.

Suitable salts of the compound (III) may be the same as those exemplified for the compound (I). Starting compounds (II) and (III) of this method
Is a known compound, and a commercially available one can be used.

When this reaction is carried out by enzymatic synthesis,
For example, known β-galactosidase can be used, and as a suitable example of such an enzyme, Bacillus
Examples include β-galactosidase derived from circulans. In this reaction, β-galactosidase is immobilized on a carrier by a conventional method, and the compound (II) is reacted with the compound (III) or a salt thereof to produce the target compound (I). .

The reaction temperature is not particularly limited, and the reaction is usually carried out at room temperature or under heating. The compound (I) obtained by the above production method can be isolated and purified by a conventional method. The yield of the target compound (I) (galactosyl kojic acid) increases with the concentrations of the compound (II) and the compound (III) or a salt thereof.

The object compound (I) of the present invention has a tyrosinase inhibitory activity and is useful, for example, as a blackening inhibitor for foods, cosmetics and the like. For example, it can be contained in skin cosmetics such as lotion, cream, emulsion and pack as a whitening agent for cosmetics. Each of these cosmetics contains 0.01 to 1 of the target compound (I) in a commonly used cosmetic base, auxiliary agent or the like.
% Can be added to manufacture. A lotion is prepared by dissolving a moisturizing agent such as glycerin, a skin nutrition agent, etc. in purified water, preservatives, fragrances, etc. in alcohol, mixing both of them and solubilizing them at room temperature. Particular amount of the target compound (I) can be added so as to be 0.01 to 1%.

[0013]

INDUSTRIAL APPLICABILITY In order to show the usefulness of the target compound (I), a data of a test for tyrosinase inhibitory activity of the target compound (I).
Data is shown below. Test Tyrosinase inhibitory activity (1) Test method L-DOPA was added to 50 mM-phosphate buffer (pH 6.8).
0.9 ml of a solution of kojic acid or galactosyl kojic acid having various concentrations was added to 2 ml of a solution prepared by dissolving 6 mM of 6 mM, and 10 mg / ml of tyrosinase (Tyrosinase 5000 manufactured by Wako Pure Chemical Industries, Ltd. was added to this mixed solution. ) 0.1 ml was added and the mixture was transferred to a glass cell for measuring absorbance and reacted at 30 ° C. The change in absorbance at 475 nm at this time was measured, and the inhibition rate was calculated from the relative value with respect to the change in absorbance when no tyrosinase inhibitor was added.

(2) Test Results The tyrosinase inhibitory activity of galactosyl kojic acid is shown in Table 1, which is almost the same as the tyrosinase inhibitory activity of kojic acid.

[0015]

[Table 1] The object compound (I) of the present invention, galactosyl kojic acid, has greater solubility and stability in water than kojic acid, and, like kojic acid, has activity against tyrosinase which catalyzes the oxidation of tyrosine, dopa and the like. It has an inhibitory action, and by utilizing this action, it can be used as an anti-blackening agent for foods, and also as a whitening agent for cosmetics because it has a remarkable inhibitory action on melanin production.

The present invention will be described in more detail below with reference to examples.

Example 1 (1) Immobilization of β-galactosidase As an immobilization carrier, a ceramic carrier (manufactured by NGK Insulators Co., Ltd.)
SM-10-C2) is treated with a 3% glutaraldehyde solution, which is washed with 0.1 M phosphate buffer (pH 6.0). Commercially available β-galactosidase (manufactured by Daiwa Kasei Co., Ltd., Bacillus circulans)
(Source) Suspend in solution and gently shake for 17 hours at 4 ° C. to bind enzyme to carrier. After washing this with 0.1 M phosphate buffer (pH 6.0), 3% glutaraldehyde solution is added again and treated at 4 ° C. for 3 hours to immobilize the enzyme. The titer of this immobilized enzyme is about 10 per gram.
It was 0 unit. Here, 1 unit of β-galactosidase enzyme means lactose concentration 4.56%, pH 6.0, reaction temperature 4
It means the amount of enzyme that liberates 1 μmol glucose in 1 minute under the condition of 0 ° C.

(2) Synthesis of galactosyl kojic acid Kojic acid 5 was added to 0.1 M-phosphate buffer (pH 6.0).
%, Lactose 20%, and the enzyme prepared above was added to the solution at 0.1 g / ml and reacted at 40 ° C. for 12 hours. The reaction solution was filtered, and the filtrate was separated / purified and quantified by high performance liquid chromatography.
The yield of galactosyl kojic acid is 24% based on kojic acid.
Met. The obtained galactosyl kojic acid has the following F
From the pH dependence of AB-mass spectrum, NMR and ultraviolet absorption spectrum, galactopyranosyl-β-O-2
-Methyl-5-hydroxy-γ-pyrone (galact
opyranosyl-β-O-2-methyl-5
-Hydroxy-γ-pyrone) Was identified. Separation / purification conditions Column: YMC-made YMC-Pack NH ₂ (20
X250 mm) Eluent; acetonitrile / water = 40/60 (v / v) Flow rate; 3 ml / min Quantitative conditions Column: YMC YMC-Pack N ₂ (6 × 1)
50 mm) Eluent; acetonitrile / 0.1 M-phosphate buffer = 3
0/70 (v / v) flow rate; 0.8 ml / min detection; UV 280 nm FAB Mass (m / z): 303 (M-1) NMR (D ₂ O, δ): 3.52-3.76 ( 5H,
m), 3.72 (2H, s), 3.91 (1H, t, J
= 2.5 Hz), 4.47 (1H, d, J = 7.6H)
z), 6.68 (1H, s), 8.07 (1H, s)

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C12P 19/58 7432-4B

Claims (2)

[Claims] 1. The formula: Or a salt thereof. 2. A tyrosinase inhibitor containing the compound according to claim 1 or a salt thereof as an active ingredient.