KR20030046123A - Kojic acid derivative and preparation method thereof - Google Patents

Abstract

PURPOSE: Kojic acid derivatives and a preparation process thereof are provided, thereby inhibiting the melanin formation, so that the whiteness of the skin can be improved. CONSTITUTION: Kojic acid derivatives represented by formula(1) are provided, wherein R is C6H4-1,4-, C6H4-1,3-, CH=CHCH=CH, C5H3N-2,5- or C5H3N-3,5-. A process for preparing the Kojic acid derivatives of formula(1) comprises the steps of: (a) reacting thionyl chloride as chlorides with kojic acid in an organic solvent to prepare kojyl chloride; (b) reacting terephthalic acid, pyridine dicarboxylic acid and 2,4-hexadiene dioic acid with hydroxide salt in an organic solvent to prepare terephthalic acid salt, pyridine dicarboxylic acid salt and 2,4-hexadiene dioic acid salt; and (c) reacting terephthalic acid salt, pyridine dicarboxylic acid salt and 2,4-hexadiene dioic acid salt with kojyl chloride to prepare kojic acid dimer, wherein the chloride of the step (a) is thionyl chloride, oxalyl chloride, phosphorous trichloride and phosphorous oxychloride; the organic solvent of the step (a) is chloroform, methylene chloride, tetrahydrofuran, acetone, toluene and benzene; the hydroxide salt of the step (b) is sodium hydroxide and potassium hydroxide; and the organic solvent of the step (b) is ethanol, methanol, butanol and isopropyl alcohol.

Description

Novel kojic acid derivatives and preparation methods thereof

The present invention relates to a novel kojic acid derivative compound represented by the following formula (1) and a method for producing the same.

[Formula 1]

Wherein R is C ₆ H ₄ -1,4-, C ₆ H ₄ -1,3-, CH = CHCH = CH, C ₅ H ₃ N-2,5- or C ₅ H ₃ N-3 , 5-.)

Human skin color is determined by red blood cells, carotene, and melanin in the blood, but differences in race color, hyperpigmentation such as blemishes and freckles are caused by melanin. Melanin in the epidermal layer, the outer skin of the skin, protects the skin organs under the dermis by acting as a sunscreen, and catches free radicals generated in the skin's living body, thus protecting proteins and genes in the skin. . However, melanin produced by internal and external stress is a stable substance that does not disappear until it is released to the outside through skin keratinization. Such melanin is produced in the body through a polymerization oxidation process using an enzyme such as tyrosinase based on tyrosine or dopa, and in particular, the generation of free radicals in the skin Increased or melanin production is increased by the effects of inflammatory reactions and ultraviolet light. In particular, ultraviolet rays may increase the production of melanin, which may partially cause melanin to develop into blemishes, resulting in undesired results, or even worse, may cause skin cancer and the like, and may pose a risk to life.

Tyrosinase is the most important enzyme in synthesizing such melanin, and many researchers have been trying to suppress the enzyme. Among these efforts, kojic acid is known as a powerful tyrosinase inhibitor, and many derivatives have been synthesized for the purpose of enhancing the activity of kojic acid. In order to enhance the tyrosinase inhibitory effect of kojic acid, there have been attempts to introduce various hydrophobic groups at the hydroxy methyl position at the 7-position. However, in most cases, the inhibitory activity of Tyrosinase was improved, but in terms of safety, it showed a tendency to decrease rather than kojic acid. For these reasons, current derivatives other than kojic acid are not widely used.

Accordingly, the present inventors conducted a thorough study of the new kojic acid derivatives in order to solve the problem of the kojic acid derivatives described above. In this case, it was found that substances that improve the inhibitory activity of tyrosinase (Tyrosinase) than the conventional kojic acid while reducing side effects of the human body represented by other derivatives.

Accordingly, an object of the present invention is to provide a kojic acid derivative represented by the following general formula (1) and a method for producing the same.

[Formula 1]

Wherein R is C ₆ H ₄ -1,4-, C ₆ H ₄ -1,3-, CH = CHCH = CH, C ₅ H ₃ N-2,5- or C ₅ H ₃ N-3 , 5-.)

Accordingly, the present invention provides a kojic acid derivative represented by the following formula (1).

[Formula 1]

Wherein R is C ₆ H ₄ -1,4-, C ₆ H ₄ -1,3-, CH = CHCH = CH, C ₅ H ₃ N-2,5- or C ₅ H ₃ N-3 , 5-.)

In addition, the method for preparing the kojic acid derivative compound of the present invention includes the following steps.

(A) reacting the thionyl chloride as a chloride with kojic acid under an organic solvent to produce cozyl chloride;

(B) terephthalic acid, pyridinedicarboxylic acid, 2,4-hexadienedioic acid and the like are reacted with hydroxides in an organic solvent to give terephthalic acid, pyridinedicarboxylate, 2,4-hexadienedioic acid salt. Manufacturing; And

(C) Koji acid dimer by reacting the terephthalic acid salt, pyridinedicarboxylate, 2,4-hexadiedidioic acid salt, etc. produced in the step (B) with an organic solvent, and the co-chloride produced in the above step (A). Manufacturing steps:

The preparation method according to the present invention can be represented by the following scheme 1.

(In formula of the said reaction degree, R is the same as what was defined by General formula (1).)

Hereinafter, a method for preparing the kojic acid derivative compound according to the present invention will be described in detail.

(A) reacting thionyl chloride which is a chloride with kojic acid in an organic solvent to produce a cozyl chloride represented by Formula (II);

Koji acid and thionyl chloride used in the above step is preferably reacted in an equivalent ratio of 1: 1 to 1: 1.3. This is because if the equivalent ratio is less than 1: 1, the desired product cannot be obtained. If the ratio is 1: 1.3 or more, an excess of by-products are generated in addition to the desired product.

In addition, the chloride used in step (A) may be used thionyl chloride, oxalyl chloride, phosphorus chloride, phosphorus oxy chloride, and the like, and as an organic solvent, chloroform, methylene chloride, tetrahydrofuran, Dioxane, acetone, toluene, benzene and the like can be used.

On the other hand, reaction temperature is 0-80 degreeC, Preferably it is 10-40 degreeC.

(B) terephthalic acid, pyridinedicarboxylic acid, 2,4-hexadiedidioic acid and the like are reacted with a hydroxide salt in an organic solvent to give a terephthalic acid salt, pyridine dicarboxylate, Preparing 4-hexadienedioic acid salt and the like;

The hydroxide salt used in step (B) of the production method of the present invention may be used sodium hydroxide, potassium hydroxide, ethanol, methanol, butanol, isopropyl alcohol and the like can be used as an organic solvent.

(C) Koji acid dimer by reacting the terephthalic acid salt, pyridinedicarboxylate, 2,4-hexadiedidioic acid salt, etc. produced in the step (B) with an organic solvent, and the co-chloride produced in the above step (A). Steps to manufacture:

Dimethylformamide may be used as the organic solvent used in the step (C).

Specific examples of the kojic acid derivatives of the formula (1) obtained by the above production method include terephthalic acid bis- (5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester [Terephthalic acid bis- ( 5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester], isophthalic acid bis- (5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester [Isophthalic acid bis- ( 5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester], 2,4-hexadienedioic acid bis- (5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester [ Hexa-2,4-dienedioic acid bis-(5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester], 2,5-pyridinecarboxylic acid bis- (5-hydroxy-4-oxo- 4H-pyran-2-ylmethyl) ester [Pyridine-2,5-dicarboxylicacid bis-(5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester], 3,5-pyridinecarboxylic acid bis- (5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester [Pyridine-3,5-dicarboxylicacidbis- (5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester] have.

Kojic acid derivative compound (1) of the present invention prepared by the above production method may be contained as an active ingredient of a whitening agent.

Hereinafter, the present invention will be described in more detail with reference to Examples and Test Examples, but the present invention is not limited only to these examples.

Reference Example 1 Preparation of Cosyl Chloride

50 g of kojic acid was dissolved in 300 ml of chloroform in a 500 ml round flask. To this was added 50.2 g of thionyl chloride at 25 ° C. and further stirred at the same temperature for 4 hours. After completion of the reaction, the reaction mixture was concentrated and the residue was dissolved in ethyl acetate, and then the organic layer was washed twice with dilute hydrochloric acid solution and three times with water, and the organic layer was separated and dried. Concentrated under reduced pressure and left overnight with petroleum ether. The resulting solid was filtered and dried to give 46.7 g of a light brown cozyl chloride (yield: 83%).

Reference Example 2 Preparation of Terephthalic Acid

20 g of terephthalic acid and 13.5 g of potassium hydroxide were added to a 500 ml round flask, 400 ml of anhydrous ethanol was added thereto, stirred at 25 ° C. for 2 hours, and the solid produced by filtration was dried to give 27.7 g of white terephthalic acid salt (yield: 95%).

Reference Example 3 Preparation of Isophthalic Acid

Except for using isophthalic acid instead of terephthalic acid, 28.3 g of a white isophthalic acid salt (yield: 97%) was obtained by the same method as the reference example 2 above.

Reference Example 4 Preparation of 2,4-hexadienedioic Acid Salt

A 29.1 g (yield: 95%) of white 2,4-hexadienedioic acid salt was obtained in the same manner as in Reference Example 2, except that 2,4-hexadiedidioic acid was used instead of terephthalic acid.

Reference Example 5 Preparation of 2,5-pyridinedicarboxylate

28.5 g (yield: 98%) of 2,5-pyridine dicarboxylate was obtained in the same manner as in Reference Example 2, except that 2,5-pyridinedicarboxylic acid was used instead of terephthalic acid.

Reference Example 6 Preparation of 3,5-pyridinedicarboxylate

27.3 g of a white 3,5-pyridine dicarboxylate (yield: 94%) was obtained by the same method as the Reference Example 2, except that 3,5-pyridinedicarboxylic acid was used instead of terephthalic acid. .

Example 1 Terephthalic Acid Bis- (5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) Ester (Terephthalic acid bis- (5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester Manufacturing

10 g of terephthalate and 7.9 g of co-chloride were dissolved in 150 ml of dimethylformamide and then refluxed for 5 hours. After the reaction was completed, the reaction solution was filtered and concentrated, and 500 ml of chloroform was added to dissolve the reaction mixture. After washing twice with 0.1 N hydrochloric acid solution, dried over anhydrous manganese, filtered and concentrated, ethyl acetate was added and left overnight. The resulting solid was filtered and dried to give 10.7 g (yield = 60%) of the title compound as a pale yellow solid.

TLC (ethyl acetate) R _f = 0.62

¹ H NMR (DMSO-d ₆ , δ): 9.18 (s, 2H), 8.14 (d, 4H, J = 7.8 Hz), 8.07 (s 2H), 6.46 (s, 2H), 4.96 (s, 4H) .

Example 2 isophthalic acid bis- (5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester (Isophthalic acid bis- (5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester)

11.1 g (yield = 65%) of the title compound (yield: 65%) was obtained in the same manner as in Example 1, except that isophthalic acid salt was used instead of terephthalic acid salt.

TLC (ethyl acetate) R _f = 0.58

¹ H NMR (DMSO-d ₆ , δ): 9.19 (s, 2H), 8.68 (s, 1H), 8.18 (d, 2H, J = 7.6 Hz), 8.05 (s 2H), 7.48 (d, 1H, J = 7.8 Hz), 6.43 (s, 2H), 4.96 (s, 4H).

Example 3 2,4-hexadienedioic acid bis- (5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester (Hexa-2,4-dienedioicacidbis- (5-hydroxy-4-oxo -4H-pyran-2-ylmethyl) ester)

12.5 g of a yellow solid (yield = 70%) was obtained in the same manner as in Example 1, except that 2,4-hexadiedidioic acid salt was used instead of terephthalic acid salt.

TLC (ethyl acetate) R _f = 0.60

¹ H NMR (DMSO-d ₆ , δ): 9.16 (s, 2H), 8.05 (s 2H), 7.50 (d, 2H, J = 7.2 Hz), 6.44 (s, 2H), 6.05 (d, 2H, 7.2 Hz), 4.95 (s, 4H).

Example 4 2,5-pyridinedicarboxylic acid bis- (5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester (Pyridine-2,5-dicarboxylicacid bis- (5-hydroxy-4 -oxo-4H-pyran-2-ylmethyl) ester)

In the same manner as in Example 1, except that 2,5-pyridinedicarboxylate was used instead of terephthalate, 10.9 g (yield = 64%) of the title compound was obtained.

TLC (ethyl acetate) R _f = 0.56

¹ H NMR (DMSO-d ₆ , δ): 9.63 (s, 1H), 9.19 (s, 2H), 8.78 (d, 1H, J = 7.6 Hz), 8.58 (d, 1H, J = 7.6 Hz), 8.04 (s 2H), 6.47 (s, 2H), 4.96 (s, 4H).

Example 5 3,5-pyridinedicarboxylic acid bis- (5-hydroxy-4-oxo-4H-pyran-2-ylmethyl) ester (Pyridine-3,5-dicarboxylic acid bis- (5-hydroxy- 4-oxo-4H-pyran-2-ylmethyl) ester)

12.8 g of a yellow solid (yield = 75%) was obtained in the same manner as in Example 1 except that 3,5-pyridinedicarboxylate was used instead of terephthalic acid salt.

TLC (ethyl acetate) R _f = 0.63

¹ H NMR (DMSO-d ₆ , δ): 9.55 (s, 2H), 9.18 (s, 2H), 8.95 (s, 1H), 8.06 (s 2H), 6.45 (s, 2H), 4.94 (s, 4H).

Test Example 1 Measurement of Melanin Inhibitory Effect Using Pigment Cells

Mel-Ab cells derived from C57BL / 6 mice were cultured in Dulbecco's modified Eagle's media (DMEM) at 37 ° C and 5% CO ₂ in 10% fetal placental serum and 100 nM 12-O-tetradecanoylphore. Cultures were added in medium containing tetradecanoylphorbol-13-acetate and 1 nM cholera toxin. The cultured Mel-Ab cells were separated with 0.25% trypsin-EDTA, the cells were incubated at a concentration of 10 ⁵ cells / well in a 24-well plate, and 10 ppm of test substance (nose Local acid and Examples 1 to 5) were added thereto and cultured.

Next, the culture medium was removed, washed with PBS, cells were dissolved with 1N sodium hydroxide, and the absorbance was measured at 400 nm. Then, the inhibition of melanin production was calculated according to Equation 1 below (Dooley's method), and the results are shown in Table 1. It was.

Inhibitory Effect of Kojic Acid Derivatives on Melanogenesis Test substance Melanin production inhibition rate (% control) Kojisan 25.0 Example 1 52.3 Example 2 35.5 Example 3 40.5 Example 4 39.8 Example 5 45.7

As can be seen in Table 1, it was confirmed that the kojic acid derivatives according to the present invention has an excellent melanin production inhibition rate.

Test Example 2 Whitening Effect Test on Human Skin

Twelve healthy men were attached with an opaque tape with a hole of 1.5 cm in diameter on their upper arm and irradiated with UVB (1.5-2 times the minimum erythema of each subject) to induce skin blackening. .

After irradiation, 1% of each of Examples 1 to 5 (solvent is 1, 3-butylene glycol: ethanol = 7: 3), 3% koji acid and a solvent were applied as a control for 10 weeks, and the skin The color was measured by Chromameter CR2002 (Minolta, Japan) to evaluate the degree of increase of the "L" value ("ΔL"), and the results are shown in Table 2.

Whitening Effect of Kojic Acid Derivatives on Human Skin Test substance Skin color brightness degree (ΔL) Solvent 0.50 ± 0.15 Kojisan 0.99 ± 0.11 Example 1 0.58 ± 0.21 Example 2 1.71 ± 0.25 Example 3 1.51 ± 0.13 Example 4 1.38 ± 0.11 Example 5 1.22 ± 0.18

As can be seen in Table 2, the kojic acid derivatives of the present invention was confirmed that the whitening effect is excellent.

As described above, the kojic acid derivative compound of the present invention has an effect of inhibiting melanin production, and the cosmetic composition containing the same may be realized as an effective whitening product by improving pigmentation of the skin.

Claims (8)

Kojic acid derivative compound represented by following General formula (1). [Formula 1] Wherein R is C ₆ H ₄ -1,4-, C ₆ H ₄ -1,3-, CH = CHCH = CH, C ₅ H ₃ N-2,5- or C ₅ H ₃ N-3 , 5-.) (A) reacting the thionyl chloride as a chloride with kojic acid under an organic solvent to produce cozyl chloride; (B) terephthalic acid, pyridinedicarboxylic acid, 2,4-hexadienedioic acid and the like are reacted with a hydroxide salt in an organic solvent to give terephthalic acid salt, pyridinedicarboxylic acid salt, 2,4-hexadienodioic acid salt Preparing a; And (C) terephthalic acid salt, pyridinedicarboxylate, 2,4-hexadiedidioic acid salt and the like produced in step (B) in an organic solvent and reacted with the cozy chloride produced in step (A) Preparing a dimer; Method for producing a kojic acid derivative represented by the formula (1) shown in the following scheme, characterized in that it comprises a. Scheme 1 (In the formula of Scheme 1, R is the same as defined in claim 1). The method of claim 2, wherein the chloride used in step (A) is thionyl chloride, oxalyl chloride, phosphorus chloride, phosphorus oxychloride. The method of claim 2, wherein the organic solvent used in step (A) is chloroform, methylene chloride, tetrahydrofuran, diogan, acetone, toluene, benzene. The method for preparing kojic acid derivatives according to claim 2, wherein the hydroxide salts used in step (B) are sodium hydroxide and potassium hydroxide. The method of claim 2, wherein the organic solvent used in step (B) is ethanol, methanol, butanol, isopropyl alcohol production method of the kojic acid derivative, characterized in that. A whitening agent comprising the kojic acid derivative compound according to claim 1 as an active ingredient. The whitening method which inhibits melanin production by the kojic acid derivative compound of Claim 1.