JPS63316711A - Beautifying and whitening cosmetic - Google Patents

Abstract

PURPOSE:To obtain a novel skin beautifying and whitening cosmetic, containing dihydromyricetin, high in safety, soluble in water and alcohols and having powerful inhibitory effects on tyrosinase activity as an active ingredient. CONSTITUTION:A beautifying and whitening cosmetic containing dihydromyricetin, expressed by the formula and obtained by extracting mature leaves of a salicaceous plant, e.g. Salix sachalinensis Fr. Schm., with methanol, concentrating the resultant extract, distributing the obtained concentrate with ether and then ethyl acetate, fractionating, purifying the resultant ethyl acetate layer by silica gel column chromatography, etc. The content of the dihydromyricetin is preferably 0.001-5.0wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel skin whitening cosmetic. More specifically, dihydromyricetin (Dihydros+yri-
Cetin: C+sH+aOs: Ampelopsin: Or 3.5°? , 3=4−. A skin-whitening cosmetic containing 5-1-hexahydroxyflavanone (hereinafter referred to as dihydromyricetin) as an active ingredient has a great whitening effect.

[Conventional technology]

Although the mechanisms behind the development of skin spots, dark skin, and freckles are still unclear, in general, melanin pigments are formed due to hormonal abnormalities or stimulation of ultraviolet rays from sunlight, and this occurs within the skin. It is thought that it is abnormally deposited. Treatment methods for such spots and bruises include substances that suppress melanin production, such as oral administration of large amounts of ascorbic acid, injections of glutathione, and ointments such as L-ascorbic acid and cysteine. It is applied locally in the form of creams, lotions, etc. Additionally, in Europe and America, hydroquinone preparations are used as a treatment for age spots and freckles.

[Problem that the invention seeks to solve]

L-ascorbic acids have problems in terms of stability over time, and are particularly unstable in systems containing water, causing discoloration and odor. On the other hand, although hydroquinone is highly effective, its use is generally limited due to its sensitizing properties.
There is also a problem in terms of stability because it is easily oxidized by air. Thiol compounds such as glutathione and cysteine have a strong off-flavor, are easily oxidized, and have slow effects.

Also, 2-mercaptoethyl amyl hydrochloride and? 7N
-(2-Mercaptoethyl)dimethylamine hydrochloride and the like are known to decolorize black guinea pigs, but these compounds are unstable and highly irritating, and tend to cause vitiligo after decolorization, so they are generally not used. It has not been.

[Means to solve the problem]

In view of these circumstances, the inventors of the present invention have conducted intensive research and have completed the present invention after recognizing that the flavonoid dihydromyricetin exhibits a good skin whitening effect.

That is, the present invention is a whitening cosmetic containing dihydromyricetin represented by the following general formula as an active ingredient.

The dihydromyricetin of the present invention may be a synthetic product or a product extracted from Ten-76. Furthermore, in the case of a natural product, it may be a mixture containing dihydromyricetin instead of a pure product.

As a method for extraction from natural products, for example, the following efficient fractionation and extraction methods can be used. Mizuno et al.
Mizuo Mizuno, Minoru Tanaka, Munekazu Iinuma, Yuka Maki, Hiroyoshi Ohashi,
Hidenori Tsumu; Proceedings of the 32nd Annual Meeting of the Japanese Society of Herbal Pharmaceutical Sciences, P 5
1. Okayama, 1985 method
(Salix 5achalinensis Fr.

Schm-), Chosenia
Methanol extraction of adult leaves of plants of the Salicaceae family, such as (Bracteosa Nakai), followed by concentration, partitioning using ether and ethyl acetate, and the resulting ethyl acetate layer was further fractionated by silica gel column chromatography.
It can be obtained by purification. In carrying out the present invention, the blending amount of dihydromyricetin is o, o in the total amount of cosmetics.
oi to 5% by weight, preferably 0.005 to 3% by weight. If it is less than 0.0%, the effects referred to in the present invention will not be sufficiently exhibited, which is not preferable. It is also possible to incorporate 5% by weight or more, but no significant enhancement of the effect is observed, and it is also economically unfavorable.

In addition to the above-mentioned essential ingredients, the cosmetic of the present invention may contain various ingredients commonly used in cosmetics, such as oils and fats, waxes, hydrocarbons, etc., if necessary, within a range that does not impair the effects of the present invention.
Fatty acids, alcohols, synthetic esters, surfactants, humectants, thickeners, inorganic substances, fragrances, drugs, water, etc. can be blended.

〔Effect of the invention〕

The whitening cosmetic of the present invention has a strong tyrosinase activity inhibiting effect. In addition, the present applicant has applied for a patent (patent application filed in 1983).
-041173), it is highly safe and soluble in water and alcohol, so it can be easily used as a cosmetic.

Next, the effects of the present invention will be explained in more detail with reference to experimental examples.

[Experimental Example-1] Dihydromyricetin was dissolved in water to obtain a dihydromyricetin aqueous solution with a concentration of 1.0 mM. The results of examining the ability of this aqueous solution to inhibit tyrosinase activity will be explained below.

Put one tyrosine solution (0.3 mg/ml) into a test tube.
ml, Matsukurupain's buffer (p)l 6.8)
I ml.

and dihydromyricetin aqueous solution 0.91 to 37
After incubating for 10 minutes in a thermostatic water bath at ℃, tyrosinase solution (1 mg/ml) was added to it at 0.1゛1.
In addition, the mixture was stirred and the absorbance at 475 nm was immediately measured over time using a spectrophotometer.

On the other hand, as a blank test, similar absorbance measurements were performed using water instead of the aqueous solution.

Next, as a comparative example, an aqueous solution was prepared in the same manner as in the experimental example using ascorbic acid, and its ability to inhibit tyrosinase activity was examined.

The test results in these experimental examples and comparative examples are shown in the attached drawings (graphs). From this graph, it can be seen that the aqueous solution obtained in Experimental Example 1 has a more remarkable ability to inhibit tyrosinase activity than the aqueous solution consisting of ascorbic acid. Furthermore, the present invention is characterized in that, compared to ascorbic acid's ability to inhibit tyrosinase activity, which decreases over time, an aqueous solution consisting of dihydromyricetin is stable over time and has a constant inhibitory ability.

Next, an experimental example -
This will be explained by 2.

[Experimental Example 2] The whitening effect was examined by varying the amount of dihydromyricetin added. Samples (No. 1 to No. 8) shown in Table 1 were prepared by varying the amount of dihydromyricetin in the lotion of Example-1.

First panel: 40 subjects suffering from dark skin, age spots, freckles, etc.
Five people tested each sample. The lotion was applied to the face every day for one month, and the 0-judgment result was determined based on the following criteria for the lightening effect after use.
Shown in the table.

(Judgment criteria) 3-point bipigmentation became less noticeable.

2 points: Pigmentation became considerably lighter.

1 point: Pigmentation became slightly lighter.

θ point: There was no change in pigmentation.

Table 2 Based on the above results, add 0.001 Jl of dihydromyricetin.
It can be seen that a strong whitening effect is exhibited when it is blended in an amount of z or more, and that the effect is remarkable when it is added in an amount of 0.005 weight aX or more.
Next, examples of the present invention will be given, but the present invention is not limited thereto, and the blending amounts are expressed in weight %.

Example-1 Lotion ■ Dihydromyricetin 0.5 ■ Glycerin 4.0 ■ 1,3-butylene gelicol 3.0 ■ Ethyl alcohol 7.00 Polyoxyethylene (
2(1) Lauryl ether 0.5 ■Methyl paraoxybenzoate 0.1■Citric acid 0.01■Sodium citrate 0.1■Fragrance
Add appropriate amount [phase] purified water to make 100.

Mix and dissolve ingredients ■~■, ingredients ■, and ■. Separately, components (1), (2), (2), and [phase] are mixed and dissolved.

The two are then mixed and filtered through Tetron cloth (300 mesh) to form a product.

Example-2 Cream ■ Dihydromyricetin 0.1 ■ Squalane 11.5 ■ Cetyl alcohol 2.5 ■ Polyoxyethylene (2 (1) Sorbitan monostearate 1.0 ■ Polyoxyethylene (2 (1) Heptyl ether 2.5 ■1,3-butylene glycol 4.0■
Propylene glycol 3.5 ■ Titanium dioxide 7.0 ■ Red iron
0.5 [stock] yellow iron oxide
0.20 black iron oxide
0.10 methyl oxybenzoate
0.30 Fragrance Appropriate amount 0 Add purified water to make 100.

Components (1) to (2) are heated and dissolved, mixed, and kept at 70°C to form an oil phase. Components ① to ＠ are uniformly dispersed in [phase] and kept at 75°C to form an aqueous phase. Add the aqueous phase to the oil phase and emulsify and disperse to obtain 0 ingredients.
Add and cool to 30°C while stirring to form a product.

Example-3 Cream ■ Dihydromyricetin 0.05 ■ Squalane 5.50 Olive oil 3.0 ■ Stearic acid 2.00 Beeswax
2.0 ■ Octyldodecyl myristate 3.5 ■ Polyoxyethylene (2 (1
) Heptyl ether 3.0 ■Behenyl alcohol 1.5 ■Glycerin monostearate 2.501.3
-Butylene glycol 8.5■Ethyl paraoxybenzoate 0.20Fragrance
Appropriate amount 0 Add purified water 10
Set to 0.

Components (1) to (2) are heated and dissolved, mixed, and kept at 70°C to form an oil phase. Ingredients [phase], ① are heated to 0 and mixed, 75
Keep at ℃ to form aqueous phase. Add the water phase to the oil phase and add 0 ingredients.
After uniformly emulsifying the mixture, cool to 30°C while stirring to form a product.

Example-4 Emulsion ■ Dihydromyricetin 2.0 ■ Squalane 5.00 Olive oil 5.0 ■ Jojoba oil
5.0 ■ Cetyl alcohol 1.50 Glycerin monostearate 2.0 ■ Polyoxyethylene (2
(1) Heptyl ether 3.0 ■Polyoxyethylene (2(1) Sorbitan monostearate 2.0 ■Glycerin 7.00 Flavor appropriate amount ■Methyl paraoxybenzoate 0.30 Add purified water to make 100.

Components (1) to (2) are heated and dissolved, mixed, and kept at 70°C to form an oil phase. Ingredients (1) and (2) are heated to 0 and mixed and kept at 75°C to form an aqueous phase. Add the aqueous phase to the oil phase, further add component 0, emulsify uniformly, and cool to 30° C. while stirring to obtain a product.

[Brief explanation of drawings]

The figure is a graph showing the relationship between the degree of coloring and time to show the tyrosinase activity inhibiting power of each aqueous solution obtained in Experimental Example-1.

Claims (2)

[Claims] (1) A whitening cosmetic containing dihydromyricetin represented by the following general formula as an active ingredient. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ (2) The whitening cosmetic according to claim 1, which contains 0.001 to 5.0% by weight of dihydromyricetin.