JPH09255549A - Skin humectant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new skin humectant effective for imparting the skin with moist feeling and emollience. SOLUTION: This skin humectant is composed of a sugar ester of a monosaccaride or a disaccharide and a fatty acid, concretely, a sugar ester of mycolic acids, especially <=50C lower mycolic acids, more preferably 30-40C mycolic acids and a monosaccharide such as glucose or mannose or a disaccharide such as trehalose. The sugar ester is produced from an acid fast bacterium, especially bacterium belonging to the genus Rhodococcus and extracted from cultured bacterial cell.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel skin moisturizer, that is, a skin moisturizer that imparts moisturizing and softness to the skin.

[0002]

2. Description of the Related Art It is a well-known fact that the water content of the stratum corneum is important for moisturizing and softening human skin. The water content of the stratum corneum is said to be retained by water-soluble components contained in the stratum corneum, that is, free amino acids, organic acids, urea or inorganic ions. Conventionally, these substances alone are Alternatively, it has been used in combination with a medicated dermatological agent or cosmetics for the purpose of improving or preventing rough skin.

In addition to these, many moisturizing substances have been developed and used for the same purpose, as represented by plant extracts such as aloe extract, which have a high affinity with water. .

However, when a moisturizing substance which is a water-soluble component present in the stratum corneum is applied to the skin, its action is
It is in the stratum corneum of the skin and supplies water to the stratum corneum. Moreover, the effect was temporary, and it was not intended to fundamentally improve the water-retaining ability of the stratum corneum and essentially prevent or cure rough skin.

Recently, it has been found that lipids existing between keratinocytes have a high moisturizing ability, and the artificial intercellular lipid composed of a substance having a structure similar to the interkeratinocyte lipid component Although substitutions have been attempted, the chemical synthesis of these substances produces only racemates and analogs, and the discovery of natural lipid moisturizers has been desired.

When these artificial intercellular lipids are applied to the skin, the water-retaining ability of the stratum corneum is fundamentally improved, and the effect of preventing or healing rough skin can be temporarily obtained to some extent. However, the interrelationship between artificial intercellular lipids and the skin has not been sufficiently investigated,
It has not reached a level close to that of natural skin, and it has not been a satisfactory skin moisturizer.

The present invention has been made in view of the above-mentioned drawbacks of conventional examples, and an object thereof is to restore the water retaining ability of the stratum corneum to a level equivalent to that of healthy skin. The purpose is to develop a skin moisturizer that gives moisture and softness to the skin.

Under such circumstances, conventionally, mycolic acid ester with glucose, fructose, sucrose or trehalose has been obtained in cells or medium of cells belonging to the genus Corynebacterium, Nocardia or Mycobacterium. There is. Of these, mycolic acid esters, which are present on the cell surface of the bacterial cells, are particularly well-adhered to the stratum corneum of the skin, and Corynebacterium is said to be one of the influential factors for their existence as skin-resident bacteria. In view of the above, the present inventors have focused their attention on intercellular lipids in the corneum to solve the above-mentioned problems, and conducted diligent research. As a result, the sugar ester of the monosaccharide or disaccharide of the present invention and a fatty acid However, they have found that they have the effect of fundamentally improving the water retaining ability of the stratum corneum of the skin, and have completed the present invention.

[0009]

Means for Solving the Problems The skin preservative of the present invention comprises:
It is characterized by being composed of a sugar ester of a monosaccharide or a disaccharide and a fatty acid.

The sugar ester of the present invention is one in which a carboxylic acid residue of a fatty acid and an alcohol residue of a sugar form an ester bond, and one molecule of fatty acid or two or more molecules of a fatty acid form an ester bond with a sugar. .

The fatty acids mainly correspond to fatty acids produced by various fungi represented by, for example, the genus Corynebacterium, the genus Nocardia, or the genus Mycobacterium, and are particularly represented by the following formula 1. Mycolic acid

[0012]

(Equation 1) Is preferred.

In the formula 1, Rm and Rn each represent an alkyl group, but Rm and Rn may be linear or branched, and Rm and Rn are each an unsaturated bond, It may have a double bond, and is used in a broader concept than a normal alkyl residue.

The mycolic acid in the present invention has a total carbon number of 50 or less, more preferably 30.
When the carbon number is 50 or more, the toxicity is enhanced, and when the carbon number is 30 or less, the water retention ability is significantly reduced.

Examples of the sugar that forms an ester bond with mycolic acid include monosaccharides such as glucose, mannose and fructose, and various disaccharides such as sucrose and trehalose. These sugars
It may be either aldose or ketose, and may have either a chain structure or a cyclic structure. For example, trehalose-6,6'-dimycolate, trehalose-6-monomycolate, glucose-6-monomycolate, mannose-6-mycolate, fructose-
6-mycolate is mentioned.

The sugar ester of the present invention, mainly mycolic acid sugar ester, is mainly extracted from bacterial cells by culturing, for example, a bacterium belonging to the genus Rhodococcus, particularly a Rhodococcus bacterium, to produce the compound in the bacterial cells. Can be obtained by

For the culture method at that time, known synthetic media and natural media which have been used conventionally can be used,
In particular, any medium can be used as long as it is a medium used for culturing microorganisms belonging to the genus Rhodococcus.

For example, monosaccharides such as glucose, fructose and mannose can be used as the growth carbon source. As the nitrogen source, for example, inorganic nitrogen compounds such as potassium nitrate, sodium nitrate, ammonium sulfate and ammonium phosphate, and organic nitrogen compounds such as peptone, meat extract and corn steep liquor can be used. Further, as inorganic salts, sodium, potassium, calcium, zinc, magnesium, manganese, phosphoric acid, etc.,
Furthermore, as growth factors, various vitamins, amino acids,
Alternatively, yeast extract rich in them may be appropriately added.

The optimum pH of the medium is 5-9, especially 7-7.5, and the culture temperature is 10-40 ° C, especially 30-4.
0 ° C. is suitable. The culture is preferably performed in liquid culture or solid culture under aerobic conditions. It is appropriate that the culture time is usually about 3 to 14 days.

In order to obtain the mycolic acid sugar ester from the bacterial cells thus obtained, a usual method for collecting bacterial cell components may be used. For example, the culture solution is centrifuged to collect the cells, and then an organic solvent is added to carry out solvent extraction. For example, as the organic solvent, a mixed solution of chloroform and methanol, a mixed solution of chloroform, methanol, and acetone, such as a hydrophobic solvent such as chloroform and a hydrophilic solvent such as methanol and acetone, may be used alone or in combination. .

Next, the extracted bacterial cell component is adsorbed on silica gel, molecular sieve or the like, and then eluted with the solvent as described above for further purification. Then, by utilizing the difference in solubility in solvents and the difference in ionic bond strength,
The mycolic acid sugar ester is a mixture of mycolic acid sugar esters having different carbon numbers, but is almost pure by a single method, or by appropriately combining two or more methods, or by repeating the same operation several times. Can be separated and purified as a simple substance.

The sugar ester of mycolic acid thus purified can be used as it is, or diluted with a suitable solvent or further mixed with a suitable excipient, and various ointments can be prepared by a conventional formulation means. , Can be used as an external skin agent. For example, various types of water / oil represented by creams, emulsions, oil / water emulsion cosmetics, lipsticks,
It can be applied as a foundation, a skin cleanser, a hair restorer and the like.

As the mycolic acid sugar ester, it is not necessary to extract it from the cells by the above-mentioned method and to purify it to a pure product, and it may be used as a mixture of various mycolic acid sugar esters. Furthermore, to the extent that toxicity is not exerted and an appropriate water retention action is exerted,
It may be used as a crudely purified bacterial cell extract. of course,
A mycolic acid sugar ester can also be obtained by synthesis, and a highly pure mycolic acid sugar ester can be obtained by the synthesis.

[0024]

EXAMPLES Examples of the present invention will be specifically described below, but the present invention is not limited thereto.

(Example 1) [Cultivation of bacterial cells] Rhodococcus
s sp. 4306) was taken in 1 platinum loop and adjusted to pH 7.5, and inoculated into 200 ml of PYG (M, F) medium for culture having the composition shown below, and precultured by a shaking culture method at 37 ° C. for 5 to 7 days. did. 10-50 ml of this pre-cultured bacterial solution
(The amount of the liquid is appropriately adjusted depending on the cell concentration of the precultured bacterial liquid.) Was added to 1.5 L of PYG (M, F) medium having the same composition, and main culture was performed at 37 ° C for 5 to 7 days.

[Composition of PYG (M, F) medium] -polypepton (manufactured by Nippon Pharmaceutical Co., Ltd.) 0.5% -yeast extract (manufactured by DIFCO) 0.5% -sugar (D (+)-Glucose, manufactured by Wako Pure Chemical Industries) 1% However, in addition to D (+)-Glucose,
D (+)-Mannose, D (-)-Frucrto
se can also be used.

[Extraction and Purification of Mycolic Acid Sugar Ester] The cultured bacterial solution thus obtained is centrifuged at 7,500 rpm for 30 minutes to collect the bacterial cells. Next, a mixed solution of chloroform and methanol (volume ratio 2: 1) is added to the collected bacterial cells, and ultrasonication is performed for 15 minutes by an ultrasonic homogenizer. The treated solution is transferred to a separating funnel, water is added to separate into two layers, and the solvent phase is separated. Then, the separated solvent was concentrated by an evaporator to obtain a lipid component.

Further, this lipid component was developed by thin layer chromatography and separated and purified. That is, the lipid component is dissolved in a suitable solvent such as a small amount of chloroform, and the thin layer plate for preparative separation made of silica gel (UNIPLATE SI
It spotted on LICA GEL G MERCK company. Then, the mixture was developed with a mixed liquid of chloroform, methanol, acetone, and acetic acid (volume ratio, 90: 10: 6: 1). Next, each lipid portion separated on this thin layer plate was scraped off, and the scraped silica gel was filled in a glass column and eluted with a mixed liquid of chloroform and methanol (volume ratio 2: 1), Repeat until a single spot appears on the thin-layer chromatogram. Finally, the solvent layer was evaporated to remove trehalose-6-monomycolate, trehalose-6,6'-dimycolate, glucose-6-monomycolate, mannose-6.
-Mycolate, fructose-6-mycolate was obtained.

Regarding these mycolic acid sugar esters,
First, the structure of mycolic acid was analyzed as follows. First, after culturing the cultivated Rhodococcus, after hydrolyzing with 10 w / w% potassium hydroxide,
Adjust to pH 2 with 6N hydrochloric acid, add hexane, and shake well. Then, the mixture was allowed to stand and separated into two layers, and the hexane layer was separated and concentrated to dryness. Benzene and methanol,
Add 2 ml of a mixture of sulfuric acid (volume ratio 10: 20: 1) and add 1
Methyl esterification was carried out at 00 ° C. for 1 hour. continue,
Water and hexane (2 ml each) were added, the hexane layer was separated, and the hexane layer was concentrated to dryness again. This was dissolved in a small amount of hexane and developed with a mixed solution of hexane and diethyl ether (volume ratio 4: 1) using the above-mentioned thin plate for fractionation to fractionate the lipid component.

A mixed solution of N, O-bis (trimethylsilyl) trifluoroacetamide and pyridine (volume ratio 2: 1) was added to this lipid component, and the mixture was reacted at 95 ° C. for 1 hour to give T.
It was converted to MS (trimethylsilyl). Then benzene 2
The mixture was dried several times with a rotary evaporator while adding ml several times, and then dissolved by adding a small amount of hexane. GC / MS (gas chromatography /
Mass spectrometry). The result is shown in FIG. FIG.
As can be seen from the above, it was found that the number of carbon atoms of mycolic acid extracted from the Rhodococcus bacterium was mainly 36 and was distributed in the range of 32 to 38. In addition, what is shown in the parentheses in the figure is the number of carbon atoms constituting Rm and Rn in Formula 1.

Next, five types of separated and purified mycolic acid sugar esters (trehalose-6-monomycolate, trehalose-6,6'-dimycolate, glucose-6-
FAB for monomycolate, mannose-6-mycolate, and fructose-6-mycolate, respectively.
/ MS (fast atom bombardment
2)
Mass spectra as shown in (a) and (b) and FIGS. 3 (c) to (e) were obtained. According to this, each of the five kinds of mycolic acid sugar esters obtained above has 3 carbon atoms.
It was confirmed that it consisted of 0 to 40 mycolic acid.

Next, among the various mycolic acid sugar esters thus obtained, mannose-6-dimycolate (hereinafter referred to as MM) was confirmed to have the effect of retaining water.

(Hygroscopicity Test) A hygroscopicity test was carried out by the gravimetric method with respect to MM as the mycolic acid sugar ester which is the skin moisturizer of the present invention, using sphingolipid as a comparison. First, MM and sphingolipid were each added to 10
Each mg was weighed into a separate test tube. A suitable amount of a mixture of chloroform and methanol (volume ratio 2:
After 1) was added and dissolved, the solvent was removed with nitrogen gas so as to form a uniform film on the test tube wall. Then, after thoroughly drying in a vacuum desiccator,
The weight was measured. Next, these are subjected to humid conditions (40
It was allowed to absorb moisture at 98 ° C, and the weight was measured again. The rate of change between the weight of each of these samples after drying and the weight after absorbing moisture was defined as the moisture absorption capacity.

According to these results, the sphingolipid had an increase of only 12.5%, but the MM had a significant increase of 68.0%, which showed that it had an excellent moisturizing ability. You can see that

(Measurement of Skin Conductance) Next, a cream was prepared using the MM of the present invention, and the skin conductance after applying the cream was measured. [Preparation of Cream] First, (1) to (8) are mixed and heated to 75 ° C. according to the component amounts shown in the following Formulation 1 to obtain an oil phase. Separately from this, (9) and (10) were mixed, heated and melted to 75 ° C., and the aqueous phase was added to the above oil phase and uniformly emulsified with a homomixer to give a water-in-oil type cream of Example. Got Further, in the same manner, a control cream containing no MM was obtained.

[Formulation 1] Cream component (%) Example Control example (1) MM 0.5 0.0 (2) Octyldodecyl myristate 1.0 1.0 (3) Tri (capryl-capric acid) glycerin 8.0 8.0 (4) Batyl alcohol 5.0 5.0 (5) Lanolin 2.0 2.0 (6) Polyoxyethylene tristearate sorbitan (20 EO) 1.0 1.0 ( 7) Self-emulsifying glyceryl monostearate 5.0 5.0 (8) Preservative proper amount proper amount (9) 1,3-butylene glycol 7.5 7.5 (10) purified water residual amount residual amount

[Measurement of Skin Conductance] Using the creams of Examples and Controls obtained above, skin conductance was measured. Ten healthy subjects were used as test subjects, and the cream of the example and the cream of the control were applied to the flexed part of the upper arm, and the water content of the stratum corneum was measured by a skin conductance meter (manufactured by IBS). FIG. 4 shows the results. In the figure,-○-is the cream of the example,
−Δ− indicates the cream of the control example.

As can be seen from FIG. 4, both the cream of this example and the cream of the control example reached a maximum about 10 minutes after the skin application, then decreased rapidly, and returned to a plateau after about 20 to 30 minutes. However, at this time, in the cream of this example, the skin conductance was larger than that of the cream of the control example, and even when the plateau state was restored,
The state was larger than that of the control example. Rather than this
It can be seen that M has a good water retention capacity. In addition, other mycolic acid sugar esters similarly showed good water retention ability.

Further, various cosmetics were produced using the MM of the present invention. Also in the following examples, the isolated and purified MM was used.

Example 2 A lotion was prepared according to the following formulation 2.

[Formulation 2] Toner lotion Blending ingredients Blending amount (wt%) (1) MM 0.1 (2) Ethanol 10.0 (3) Polyoxyethylene nonyl phenyl ether (9 EO) 0.1 ( 4) Glycerin 2.0 (5) Preservative proper amount (6) Purified water balance

The above components (1) to (3) were mixed at room temperature, and (4) to (6) were sequentially added and mixed to obtain a lotion.

Example 3 An emulsion was prepared according to the following formulation 3.

[Formulation 3] Emulsion Blending component Blending amount (wt%) (1) MM 0.1 (2) Stearic acid 2.0 (3) Cetanol 1.5 (4) Squalane 5.0 (5) Self-emulsification Type Glycerin monostearate 2.0 (6) Glycerin 2.0 (7) 1,3-butylene glycol 6.0 (8) Sodium hydroxide 0.03 (9) Preservative proper amount (10) Purified water balance

The above components (1) to (5) are mixed and mixed at 70 ° C.
It is heated and melted to form an oil phase. Apart from this, (6) to (1
0) was mixed and dissolved, and the oil phase was added to the aqueous phase heated to 70 ° C., and the mixture was uniformly emulsified with a homomixer. Then, it cooled to 30 degreeC, stirring, and obtained the emulsion.

Example 4 An essence was prepared according to the following formulation 4.

[Formulation 4] Essence Blending component Blending amount (% by weight) (1) MM 0.1 (2) Ethanol 10.0 (3) Glycerin 10.0 (4) Sodium carboxymethyl cellulose 0.1 (5) Preservative Appropriate amount of agent (6) Residual amount of purified water

After the above components (1) and (2) were mixed at room temperature, (3) to (6) were added and stirred to obtain an essence.

Example 5 A foundation was prepared according to the following formulation 5.

[Formulation 5] Foundation Blending component Blending amount (% by weight) (1) MM 0.1 (2) 1,3-butylene glycol 5.0 (3) Sodium carboxymethyl cellulose 0.1 (4) Aluminum silicate Magnesium 0.05 (5) Purified water Residual amount (6) Yellow iron oxide 0.07 (7) Black iron oxide 0.01 (8) Red iron oxide 0.02 (9) Titanium oxide 5.0 (10) Talc 4 0.0 (11) Stearic acid 2.0 (12) Cetanol 1.0 (13) Squalane 5.0 (14) Self-emulsifying glyceryl monostearate 2.0 (15) Preservative Suitable amount

The above components (1) to (5) are mixed and the mixture is heated to 70 ° C.
It is heated and dissolved by, and a mixture of (6) to (10) is added in advance and sufficiently stirred. This is (11)-
After (14) was mixed and dissolved, added to the oil phase heated to 70 ° C.,
It was emulsified uniformly with a homomixer. Then, it cooled to 30 degreeC, stirring, and obtained the foundation.

Example 6 A pack was prepared according to the following formulation 6.

[Formulation 6] Pack Blending component Blending amount (wt%) (1) MM 0.1 (2) Polyvinyl alcohol 10.0 (3) Vinyl acetate resin emulsion 10.0 (4) Ethanol 5.0 (5 ) Kaolin 15.0 (6) Glycerin 1.0 (7) Preservative proper amount (8) Purified water balance

After mixing (6) with the above component (8),
(3) and (5) were added, and (2) moistened to part of (4) was added, and heated to 70 ° C. to dissolve. Next, (1) and (7) were added to the remaining component (4), a dissolved product was added, and the mixture was cooled to obtain a pack.

[0055]

According to the skin moisturizing agent of the present invention, it is expected that the water-retaining ability of the stratum corneum can be enhanced, and that the skin moisturizing agent can exert excellent improving power and preventive effect against rough skin and the like.

[Brief description of drawings]

FIG. 1 is a gas chromatograph showing the carbon distribution of mycolic acid in mycolic acid sugar ester, which is one example of the present invention.
It is a gas chromatogram by mass spectrometry.

FIG. 2 is a FAB / MS mass spectrum of the mycolic acid sugar ester, which is one example of the above, showing (a) trehalose-6-monomycolate and (b) trehalose-6,6′-dimicholate. This is McSpectrum.

FIG. 3 is a FAB / MS mass spectrum of the mycolic acid sugar ester of one example of the above, (c) is glucose-6-monomycolate, and (d) is mannose-6.
-Mycolate, (d) is a mass spectrum for fructose-6-mycolate.

FIG. 4 is a view showing the results of a comparative test of skin conductance using a cream using mycolic acid sugar ester (MM) which is one example of the above and a cream of a control example.

Front page continuation (72) Inventor Kiwa Ikeda 2-6-11 Nishihonmachi, Nishi-ku, Osaka-shi, Osaka Inside Club Cosmetics Co., Ltd.

Claims (5)

[Claims] 1. A skin moisturizer comprising a sugar ester of a monosaccharide or a disaccharide and a fatty acid. 2. The skin moisturizer according to claim 1, wherein the fatty acid is mycolic acid. 3. The skin moisturizer according to claim 1, wherein the fatty acid has 50 or less carbon atoms. 4. The skin moisturizer according to claim 1, 2 or 3, wherein the fatty acid has 30 to 40 carbon atoms. 5. A skin moisturizer comprising a bacterial cell extract extracted from an acid-fast bacterium, which comprises the sugar ester according to claim 1, 2, 3 or 4.