WO2005063688A1

WO2005063688A1 - Sphingolipid-rucinol derivatives and composition for skin external use containing the derivatives

Info

Publication number: WO2005063688A1
Application number: PCT/KR2004/003446
Authority: WO
Inventors: Sungjin Park; You-A Hwang; Jinwook Kim; Changseo Park
Original assignee: Doosan Corporation
Priority date: 2003-12-26
Filing date: 2004-12-24
Publication date: 2005-07-14
Also published as: KR20050066660A

Abstract

Disclosed are sphingolipid-rucinol derivatives, which comprise sphingolipid selected from the group consisting of N-acetylphytosphigosine, N-acetylsphiganine and N-acetylsphingadiene, and rucinol, and compositions for skin external use containing the derivatives. The sphingolipid-rucinol derivatives and the compositions exhibit an improved skin whitening effect. Further, the derivatives and compositions show an improved solubility of sphingolipid and a decreased toxicity and, accordingly, have broad applications.

Description

SPHINGOLIPID-RUCINOL DERIVATIVES AND COMPOSITION FOR SKIN EXTERNAL USE CONTAINING THE DERIVATIVES

TECHNICAL FIELD

The present invention relates to sphingolipid derivatives and a composition containing the derivatives. More specifically, the present invention relates to sphingolipid-rucinol derivatives formed by combining sphingolipid selected from a group consisting of phytosphingosine, sphinganine and sphingadiene with rucinol and a skin whitening use of the derivatives.

BACKGROUND ART

Hyperpigmentation in the skin causes a serious mental stress in view of beauty and also a hindrance to a social activity. In addition, according to social changes of that a white and delicate skin is a standard of beauty, developments of a whitening agent are actively performed. Recent researches of the whitening agent are focused on controlling various factors participating in a melanin synthesis process. For example, the researches are progressed to a ultraviolet block, a control of cytokine or hormone, a control of an internal signal of melanocyte, an inhibition of activity of tyrosinase enzyme, an inhibition of movement of melanosome, and a quick desquamation of melanin pigmented skin cell. Sphingolipid is known as a material participating in a signal transduction in a cell and thus performing an important role in growth, differentiation and death of the cell. Ceramide is the most existing lipid in the skin and known as a material suppressing an evaporation of moisture from the skin and preventing an aging and a cutaneous disorder. In addition, it is known that phytosphingosine, which is a long chain base of sphingolipid, or acetylated derivatives thereof have excellent antibacterial and anti- inflammatory effects and participate in biosynthesis of ceramide in the skin. However, a research of ceramide or sphingolipid derivatives in keratinocytes has been actively progressed, but a research of melanin synthesis is not currently much progressed. Kim, et al. (Kim, Dong-Seok, Cellular signaling 14 (2002) 779-785) performed a research on a participation of sphingolipid derivatives in melanin synthesis for the first time, and reported that ceramide derivatives (C2 ceramide) exhibit an excellent effect of suppressing melanin synthesis at 1 ~ 10 μM, compared to kojic acid. In addition, it was reported that sphingosine-1 -phosphate suppresses the melanin synthesis through a control of a signal transduction process of the melanin synthesis. Meanwhile, Doosan Corporation proved N-acetylphytosphingosine, which is a derivative of phytosphingosine, to have a skin whitening effect and filed the patent application regarding it (Korean Patent Application No. 2002-72043). Meanwhile, rucinol is an ingredient having a structural similarity to a material contained in a fir tree and has an excellent hindrance effect of tyrosinase enzyme which is a cause of skin pigmentation due to ultraviolet, etc., compared to prior whitening ingredients. The rucinol has also an advantage of being apt to mixing since it has only to use a small amount. U.S. Patent No. 6,132,740 discloses a skin whitening effect of 4- cyclopentylresorcinol, Korean Patent Application Nos. 98-911 and 97-403097 disclose a use of dibenzoylresorcinol as a ultraviolet absorbent, and Korean Patent Application No. 97-44919 discloses a use of 4,6- dibenzoylresorcinol as a ultraviolet absorbent. In addition, Welskin Corporation filed a patent application disclosing a composition containing rucinol and sphingolipid (Korean Patent Application No. 10- 2001-0013592).

DISCLOSURE OF INVENTION

The object of the present invention is to prevent hyperpigmentation of melanin by suppressing an activity of tyrosinase using sphingolipid derivatives, thereby preventing or treating skin pigmentary symptoms such as melasma, ephelis, senile pigment spots and skin hyperpigmentation, etc. The other object of the invention is to provide a composition for skin external use having such effects. In order to accomplish the object, the derivative of the present invention is a sphingolipid-rucinol derivative formed by combining sphingolipid selected from the group consisting of phytosphingosine, sphinganine and sphingadiene with rucinol. The sphingolipid-rucinol derivative is one of compounds having following formulas 1 to 3. [formula 1 ] Rucino

[formula 2] Rucinok

[formula 3 ] Riici nok

In the above formulas, Ri is independently hydrogen, alkyl group of C_1-4o, alkenyl group of Cι_-40, alkynyl group of Cι- o, acyl group or aryl group. When Ri is acyl group (COR₂), R₂ is alkyl group, alkenyl group, alkynyl group or aryl group. X is NR₃-, -O-, -S- or Xι-alk-X₂, wherein R₃ is hydrogen, alkyl group of Cι_-6, acyl group or aryl group, Xi and X₂ are independently amino group, amido group, carboxyl group, carbamate group, carbonyl group, urea or phosphoro-, and alk is alkylene of Cι_-6. A composition for skin external use according to the invention contains the sphingolipid-rucinol derivative as described above as an effective ingredient. The composition for skin external use according to the invention may be used for suppressing an activity of tyrosinase. The composition for skin external use according to the invention may be used for skin whitening. In the composition for skin external use according to the invention, the sphingolipid is preferably phytosphingosine and the composition is preferably an antibacterial composition. In the composition for skin external use according to the invention, the composition is a cosmetics composition. According to the invention, the composition contains preferably 0.005 ~ 10 wt.% of the sphingolipid-rucinol derivative. A method of suppressing an activity of tyrosinase according to the invention preferably uses the sphingolipid-rucinol derivative. A method of suppressing a melanin synthesis according to the invention preferably uses the sphingolipid-rucinol derivative.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a photograph showing a melanin production inhibiting effect of a sphingolipid-rucinol derivative according to an embodiment of the invention; FIG. 2 is a graph showing a variation of an OD value (475 nm) according to the amounts of tyrosinase; and FIG. 3 is a graph showing an effect of inhibiting an activity of tyrosinase of a sphingolipid-rucinol derivative according to an embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will be described. The invention relates to sphingolipid derivatives. More specifically, the derivatives of this invention are sphingolipid derivatives having improved whitening and antioxidant effects by combining rucinol with derivatives based on sphingolipid such as phytosphingosine. The sphingolipid-rucinol derivatives obtained according to the invention exhibit the existing whitening effect provided by the rucinol and are expected to have a physiological activity in the skin, which is provided by sphingolipid. In the present invention, a result of a whitening effect of sphingolipid-rucinol derivatives having excellent whitening and antioxidation effects is shown, compared to only each of rucinol and sphingolipid or a simple mixture of rucinol and sphingolipid. Further, the invention improves the whitening effect using derivatives formed by selecting a specific sphingolipid from many sphingolipids and combining the selected sphingolipid with rucinol. A preferred example of sphingolipid-rucinol derivatives according to the invention is as follows, [formula 4]

In addition, a preferred example of the sphingolipid-rucinol derivatives according to the invention is a derivative in which in the formulas 1 to 3, Ri is independently hydrogen, alkyl group or acyl group, and X is succinate. The sphingolipid-rucinol derivatives of the invention can be made according to a following method. Firstly, rucinol is activated. Succinic anhydride is added to the rucinol in the organic solvent and thus alcohol group is replaced with carboxyl group. In the rucinol having carboxyl group replaced, an acid portion is activated using triethylamine and p- toluenesulfonyl chloride, sphingolipid is added to the activated solution by a small amount, the added solution is warmed and the 24 hours reaction is completed. The compound prepared by the above method is extracted with an organic solvent such as chloroform or a mixing solvent of chloroform/methanol and refined with an adsorption-chromatography by silica gel. The composition of the invention is characterized in that it is a composition for skin external use. Particularly, the composition may be a cosmetics composition and is preferably skin lotion, nutri-lotion, massage cream, nutri-cream, gel, pack or skin adhesion type of cosmetics formulation. The composition of the invention contains 0.005 ~ 10 wt.% of the above sphingolipid-rucinol derivative. A whitening effect of the invention can be achieved when a content of the derivative is more than 0.005 wt.%, and a formulation stability is excellent when the content is 10 wt.% or less. In addition, the composition can be a transdermal administration type formulation such as lotion, ointment, gel, cream, patch or aerosol. The skin color is determined by various skin ingredients. Among them, melanin produced by melanocyte plays the most important role. The melanocyte of the skin is regulated to exhibit a certain degree of the skin color by a genetic character according to races. However, when it is stimulated by ultraviolet, stress, cytokine, and melanin synthesis inducing materials such as a melanocyte-stimulating hormone (MSH), melanin synthesis is increased and the synthesized melanin moves to adjacent keratinocytes via melanosomes and is finally subject to a process of desquamation from the skin. Generally, a temporary change of the skin color returns to the previous skin color tlirough the above mechanism as time goes by. However, when the skin is exposed to sunlight for a long time, it often occurs that the skin color is irreversibly changed to black. Melanin is synthesized in melanosome in the melanocyte, which is originated in endoplasmin reticulum, and regularly accumulated by an internal structure of the melanosome. Tyrosinase which converts tyrosine into melanin is produced in golgi apparatus and moves to the melanosome. In the melanosome prior to maturity, tyrosine causes an oxidation-reaction by tyrosinase and biosynthesis of melanin starts. The melanosom in which the melanin synthesis begins passes through about four steps of maturity processes and then generation of matured melanosome is completed. The matured melanosome moves to adjacent keratinocytes, and the skin color is determined f according to the number, sizes and distributions of the melanin in the keratinocytes. The melanosome moves from a base layer of epidermis to keratinocyte, and to stratum corneum while protecting the keratinocyte. During moving, the melanosome is disintegrated, but the melanin maintains at its un-disintegrated state and is finally desquamated from the skin. The tyrosinase playing the most important role in the melanin biosynthesis is synthesized in the golgi apparatus, and then moves to the melanosome while being subject to a glycosylation process. After moving to the melanosome, it is converted into an activated form by physphorylation. The melanin synthesis begins when the activated tyrosinase causes an oxidation-reaction using the tyrosine as a substrate. The tyrosine is converted into DOPA (dihydroxyphenylalanine) by tyrosinase, which is again converted into DOPA quinone by tyrosinase. A part of the DOPA quinones couple with glutathione or cysteine and thus is converted into cysteinyl DOPA and finally into pheomelanin. On the other hand, after the DOPA quinone is converted into DOPAchrome, it goes tlirough 5,6- dihydroxyindole, then is converted into indole-5,6-quinone by an action of the tyrosinase, and finally into eumelanine. The tyrosinase participates in the last stage as well as in the early stage of the melanin synthesis reaction and thus is known as the most important enzyme of the melanin synthesis process. Many materials having an effect of inhibiting melanin formation were developed to inhibit an activity of tyrosinase. The composition of the invention contains also sphingolipid derivatives inhibiting the activity of tyrosinase. Each of eumelanin and pheomelanin synthesized in the melanocyte exists in a proper ratio different from each other according to races or parts in the human body, thereby causing a difference of the skin colors. The eumelanin exhibits black and brown colors, and the pheomelanin exhibits an orange color and is synthesized from two kinds of proteins, i.e., tyrosine and cysteine. The melanin functions to protect the skin from ultraviolet. It is a useful material to protect skin organs under the dermis and simultaneously to catch activated oxygen and free radicals generated from the skin, thereby protecting the proteins and nuclei acids. However, when melanin having the useful functions as described above is abnormally produced and pigmented to the skin, melasma, ephelis, and skin dyspigmentation occur. When the composition of the invention is a transdermal administration type formulation of pharmaceutical composition, a preferred dosage is 0.001~1000 mg/body weight (kg) two times per a day, based on the composition containing 0.005 ~ 10 wt.% of phytosphingosine-rucinol. Hereinafter, preferred examples of the invention will be more specifically explained. However, the invention is not limited to such examples. In the composition of the invention, particularly when a derivative is phytosphingosine-rucinol derivative, since whitening and antibacterial effects are provided, it is possible to more efficiently care the skin. Examples <Preparation example 1: preparation of sphingolipid-rucinol derivatives of the invention> 15 g (0.902 mole) of rucinol was dissolved in pyridine solvent under atmosphere of nitrogen gas and 27.1 g (0.27 mole) of succinic anhydride was added to the solution. After then, the solution was subject to a reaction at room temperature for 24 hours under a state that the light was blocked. After the completion of the reaction, pyridine was adjusted to pH 2 by adding hydrochloric acid and thus converted into a salt form, and chloroform and water were added to extract and remove it. Similarly, an excessive succinic anhydride was also extracted and removed with the water layer. 4.06 g (0.011 mole) of rucinol-carboxyl acid obtained as above was dissolved in dichloromethane solvent under atmosphere of nitrogen gas and carboxyl group was activated by using 3.09 ml (0.022 mole) of triethylamine and 2.11 g (0.011 mole) of p- toluenesulfonylchloride. After that, phytosphingosine, sphinganine or sphingadiene 7.75 g (0.024 mole) was slowly added to the solution and then was subject to a reaction for 24 hours while warming. After the completion of the reaction, the reaction was stopped by extracting with distilled water, and refined with an adsorption-chromatography by silica gel, so that compounds of the above formulas 1 to 3 were obtained. The succinate, which was introduced in rucinol by reacting with succinic anhydride, was confirmed with IH NMR (δ = 2.6 ppm, t, 4H), and finally methylene of sphingolipid (δ = 1.2 ppm, m, 48H and δ = 0.9 ppm, t, 6H) and benzene group of rucinol (δ = 6.9 ppm, 6.35 ppm, d, t, 5H) were confirmed. Accordingly, it was confirmed that the derivative having rucinol and sphingolipid coupled was synthesized. <Examples 1 to 6: preparation of cream compositions> The inventors manufactured preferred embodiments of the invention as follows. The below examples 1 to 6 cream compositions contain different concentrations of sphingolipid-rucinol derivatives. Meanwhile, a cream composition according to a comparative example as a negative control group for comparing with the Examples 1 to 6 was also prepared, [table 1 ]

Experimental example 1: inhibiting effects of sphingolipid-rucinol derivatives on the melanin production> Melanin production inhibiting effects of each of rucinol, phytosphingosine, phytosphingosine-rucinol derivative, sphinganine, sphinganine-rucinol derivative, sphingadiene, sphingadiene-rucinol derivative and kojic acid were measured. The above materials were dissolved in DMSO (Dimethyl sulfoxide) and then used. In addition, the cell line used in the invention was prepared by culturing B16F10 Melanoma which is a cell of skin cancer of mouse in DMEM (Dulbecco's Modified Eagle Medium) containing 10% FBS (Fetal bovine serum) and antibiotics in a CO₂ incubator supplied with an air containing 5%> CO , at 37°C. A method of measuring melanin content is as follows. B16F10 mouse melanoma cells were inoculated on 24-well multi-plate with 2 x 10³ cells/well and cultured in 5% CO incubator for 24 hours at 37 °C . After pre-culturing, test materials were diluted in DMEM containing no serums, the cells were treated with the test materials at each of the concentrations and then cultured for 96 hours. After washing with PBS, 0.85 N KOH was added and dissolved with ultrasonic waves, and a light absorbance was measured at 475 nm and thus an amount of melanin was measured. On one hand, eumelanin and pheomelanin were subject to a fractional quantitative analysis using a high speed chromatography and changed into production percents based on a control group. The results are shown in table 2. The resultant values are production percents of melanin and indicate production percents (%>) for a non-treated group, [table 2]

* weight ratio of phytosphingosine :rucinol = 1:1 ** weight ratio of sphinganine :rucinol = 1 :1 *** weight ratio of sphingadiene :rucinol = 1 :1 As can be seen from the above result, 100 μM of the kojic acid is required for inhibiting the melanin synthesis up to about 90%) in all samples. Meanwhile, it could be seen that sphingolipid-rucinol derivatives had a more excellent effect of inhibiting the melanin production, compared to rucinol or sphingolpid alone or mixtures of rucinol and sphingolipid. Although it is not described in this example, it was found that arbutin had an equal level of an inhibiting effect at 10 times concentration of the kojic acid and, and at 100 times of the material of the invention. Meanwhile, it was photographed that the cell line used in this experiment was collected using a centrifugation. This is shown in Fig. 1. W-PY shown in Fig. 1 indicates a phytosphingosine-rucinol derivative according to the invention. As shown in

Fig. 1 , it can be seen that the melanin synthesis was inhibited and thus color of the cell lump was not changed to black.

Experimental example 2: inhibiting effect of sphingolipid-rucinol derivatives on tyrosinase activity > The inventors performed an experiment in order to examine the effect of sphingolipid-rucinol derivatives on tyrosinase activity as follows. In this experiment, phytosphingosine-rucinol derivative was dissolved in DMSO (Dimethyl sulfoxide) as the experimental example 1. In addition, the cell line used in the invention were prepared by culturing B16F10 Melanoma which is a cell of skin cancer of mouse in a CO₂ incubator supplied with an air containing 5%o CO₂, at 37°C using DMEM (Dulbecco's Modified Eagle Medium) containing 10% FBS (Fetal bovine serum) and antibiotics. A method of measuring a tyrosinase activity inhibition is as follows. B16F10 mouse melanoma cells were inoculated on 96- well multi-plate with 1 x 10⁴ cells/well and cultured in 5% CO₂ incubator for 24 hours at 37 ^°C . After pre- culturing, test materials were diluted in DMEM containing no serums, the cells were treated with the test materials at each of the concentrations and then cultured for 96 hours. Then, they were washed twice with PBS. 1% Triton- X-100/PBS was added to it. After dissolving with ultrasonic waves, 5 μl of 10 mM L-Dopa previously prepared to be 37°C was added and reacted for 30 minutes at 37°C. Then, a light absorbance was measured at 475 nm. The results are shown in Fig. 3. The resultant values are tyrosinase activities and indicate activity (%) for a non-treated group. As can be seen from Fig. 3, it could be seen that phytosphingosine-rucinol derivatives had an effect of inhibiting about 50%> of tyrosinase enzyme activity at about 10 μM. Similarly to the results of the experiment of melanin synthesis, this showed that phytosphingosine-rucinol derivatives of very small concentrations of only 1/10 of kojic acid and only 1/100 of arbutin had the same excellent inhibitory effect as the arbutin or kojic acid.

Experimental example 3: whitening effect of cream composition of the invention on the human skin> The inventors performed this experiment to examine whether the composition of the invention actually exhibits a whitening effect on the human skin. It was measured whitening effects of the cream compositions of the examples 1 to 6, and a whitening effect of comparative example 1 was also measured to compare with the effects. For 20 healthy male persons, opaque tape having 1.5 cm diameter of perforation was stuck to the region of the arm of the examinee. Then, UV having 1.5 to 2 times of minimal erythema dose of each examinee was applied to induce blackening of the skin. After that, the cream compositions of the examples 1 to 6 and the cream composition of the comparative example 1 were respectively applied, and the extent of darkness of the skin was measured using a spectrophotometer after two months. Each of test materials was applied two times every day at morning and evening. Judgment of the effects was determined by calculating an L value indicating the light and darkness of the skin. lL = L value on a last day at which the test material was applied - L value before applying the test material. The results are shown in table 3.

[table 3]

As can be seen from the results, it could be confirmed that the sphingolipid- rucinol derivatives of the invention exhibited very excellent whitening effects according to its concentration. Experimental example 4: an anti-bacterial ability examination of phytosphingosine-rucinol derivatives> In order to examine an anti-bacterial ability of phytosphingosine-rucinol on skin harmful bacteria, the anti-bacterial ability was examined for Propionibacterium acnes, Staphylococcus aureus, Bacillus subtilis, Micrococcus species, Aspergillus niger and Pityrosporum ovale, which is dandruff bacterium. A culture medium used to examine the anti-bacterial ability for Propionibacterium acnes was prepared by equally dissolving Brain Heart Infusion 25 g, yeast extract 5 g, Casitone 4 g, L-cysteine HC1 1 g, glucose 5 g, soluble starch 1 g, Monopotassium Phosphate 15 g, ammonium sulfate 1 g, magnesium sulfate 0.2 g, and calcium chloride 0.02 g in IL of distilled water and then pressure-sterilizing. The strains were cultured at 37°C for about 3-5 days after forming an anaerobic condition using BBL GasPak Anaerobic System. After the culture, the anti bacterial ability was examined by measuring the number of bacteria. Meanwhile, Staphylococcus Medium 110 (Difco) was used for culturing

Staphylococcus aureus, Nurrient Agar was used for culturing Bacillus subtilis and Micrococcus, Potato Dextrose Agar (Difco) was used for culturing Aspergillus niger, and a culture medium containing peptone 0.1%, glucose 0.5%, yeast resin 0.01%, oxbile 0.4%), glyceryl monostarate 0.05%o, whole milk powder 0.1%> and glycerol 0.1%) was used for culturing Pityrosporum ovale. The sample of phytosphingosine-rucinol derivative used in the invention was dissolved by ethanol and used at the concentrations of 1 μg/ml, 10 μg/ml, 100 μg/ml and 1,000 μg/ml for perceiving the anti-bacterial effects. After each of microorganisms was cultured, sequentially diluted by 10 times, and applied to each of culture media, it was determined a dilution multiple forming 10³~10⁴ colonies per a flat plate culture medium. After culturing each of the microorganisms, it was diluted by the dilution multiple determined in the experiment (at this time, 0.85 % NaCl was used as a dilution solution). After sequentially diluting the sample prepared as described above in the solvent used in sample preparation to obtain a desired concentration, 1 ml of the diluted sample was added to 9 ml of the dilution solution of microorganisms and sufficiently mixed. Phytosphingosine was dissolved using ethanol with the same condition as the phytosphingosine-rucinol derivative and then used as a control group. After allowing at 37°C for 30 minutes~l hour (often mixing), the phytosphingosine was applied to a culture medium by 100 μl, cultured in each of the culturing conditions. After completing the culture, it was measured the number of colonies. The result is shown in table 4. [table 4]

As described above, the sphingolipid-rucinol derivatives of the invention inhibit the melanin synthesis by suppressing the tyrosinase activity, thereby preventing and treating skin pigmentary symptoms such as melasma, ephelis, senile pigment spot, and skin hyperpigmentation, etc. Further, the composition of the invention can be used in cosmetics and pharmaceuticals. Further, the derivatives of the invention exhibit more improved skin whitening effect due to the derivative form compared to a simple mixture of phytosphingosine and rucinol. In addition, the sphingolipid-rucinol derivatives of the invention exhibit an excellent anti bacterial effect together with a whitening effect.

Claims

WHAT IS CLAIMED IS: 1. A sphingolipid-rucinol derivative formed by combining sphingolipid selected from the group consisting of phytosphingosine, sphinganine and sphingadiene with rucinol.

2. The sphingolipid-rucinol derivative being one of compounds having following formulas 1 to 3. [formula 1 ] Ruciiiok,,

[formula 2] nok

[formula 3 ] Ruciiiok

, wherein Ri is independently hydrogen, alkyl group of Cι_{- 0}, alkenyl group of Cι_-40, alkynyl group of Cι_{- 0}, acyl group or aryl group, when Ri is acyl group (COR₂), R₂ is alkyl group, alkenyl group, alkynyl group or aryl group, and X is -NR₃-, -O-, -S- or -Xι-alk-X₂-, wherein R₃ is hydrogen, alkyl group of

Cι_-6, acyl group or aryl group, Xi and X₂ are independently amino group, amido group, carboxyl group, carbamate group, carbonyl group, urea or phosphoro-, and alk is alkylene of Cι- .

3. A composition for skin external use containing the sphingolipid-rucinol derivative according to claims 1 or 2 as an active ingredient.

4. The composition according to claim 3 which is used for suppressing a tyrosinase activity.

5. The composition according to claim 3 which is used for skin whitening.

6. The composition according to claim 3, wherein the sphingolipid is phytosphingosine and the composition is an antibacterial composition.

7. The composition according to claim 3 being a cosmetics composition.

8. The composition according to claim 3 which contains 0.005 ~ 10 wt.% of the sphingolipid-rucinol derivatives.

9. A method for suppressing a tyrosinase activity using the sphingolipid- rucinol derivative according to claims 1 or 2.

10. A method for suppressing a melanin syntliesis using the sphingolipid- rucinol derivative according to claims 1 or 2.