Preventing or ameliorating agent for pigmentation

Abstract

An object is to provide an external preparation for skin preferably usable to prevent or ameliorate pigmentation. The object is achieved by providing a preventing or ameliorating agent for pigmentation, consisting of a compound represented by the following general formula (1), an isomer thereof, and/or a pharmacologically acceptable salt thereof, and an external preparation for skin containing the same as a component: [wherein R 1 represents an unsubstituted aromatic group or an aromatic group having any substituent; R 2 represents a hydrogen atom, a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 4, or an acyl group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 4; and R 3 represents a hydrogen atom or a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 4.]

1 . A method for preventing or ameliorating pigmentation, comprising administering a compound represented by the following general formula (1), an isomer thereof, and/or a pharmacologically acceptable salt thereof to an individual in need thereof: 
       
         
           
           
               
               
           
         
       
       wherein:
 R 1  represents an unsubstituted aromatic group or an aromatic group having any substituent; 
 R 2  represents a hydrogen atom, a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 4, or an acyl group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 4; and 
 R 3  represents a hydrogen atom or a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 4. 
 
     
     
         2 . The method according to  claim 1 , wherein in the general formula (1);
 R 1  is the unsubstituted aromatic group or the aromatic group having the substituent which is a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 6, an alkoxy group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, an alkylamino group having a linear or branched alkyl chain or chains having a number of carbon atom or atoms of 1 to 6, an acyl group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, an ester group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, a halogen atom, a halogenated alkyl group, a hydroxy group, or an amino group;   R 2  is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an acetyl group, a propionyl group, or a butylyl group; and   R 3  is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a tert-butyl group.   
     
     
         3 . The method according to  claim 2 , wherein in the general formula (1);
 R 1  is an unsubstituted phenyl, naphthyl, or biphenyl group or a phenyl, naphthyl, or biphenyl group having the substituent which is a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 6, an alkoxy group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, an alkylamino group having a linear or branched alkyl chain or chains having a number of carbon atom or atoms of 1 to 6, an acyl group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, an ester group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, a halogen atom, a halogenated alkyl group, a hydroxy group, or an amino group;   R 2  is a hydrogen atom, a methyl group, or an acetyl group; and   R 3  is a hydrogen atom, a methyl group, or an ethyl group.   
     
     
         4 . The method according to any one of  claims 1  to  3 , wherein the compound represented by the general formula (1) is N-benzoyl-serine, N-(p-methylbenzoyl)serine, N-(p-ethylbenzoyl)serine, N-(p-methoxybenzoyl)serine, N-(p-fluorobenzoyl)serine, N-(p-trifluoromethylbenzoyl)serine, N-(2-naphthoyl)serine, N-(4-phenylbenzoyl)serine, N-(p-methylbenzoyl)serine methyl ester, N-(p-methylbenzoyl)serine ethyl ester, N-(2-naphthoyl)serine methyl ester, N-benzoyl-O-methylserine, N-(p-methylbenzoyl)-O-methylserine, N-(p-methylbenzoyl)-O-acetylserine, N-(2-naphthoyl)-O-methylserine, an isomer thereof, and/or a pharmacologically acceptable salt thereof. 
     
     
         5 . A preventing or ameliorating agent for pigmentation, consisting of a compound represented by the following general formula (2), an isomer thereof, and/or a pharmacologically acceptable salt thereof: 
       
         
           
           
               
               
           
         
       
       wherein:
 R 4  represents an unsubstituted aromatic group or an aromatic group having any substituent (provided that unsubstituted phenyl group is excluded); 
 R 5  represents a hydrogen atom, a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 4, or an acyl group having a linear or branched chain alkyl chain having a number of carbon atom or atoms of 1 to 4; 
 R 6  represents a hydrogen atom or a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 4; and 
 at least one of R 5  and R 6  is any group other than the hydrogen atom when R 4  is a phenyl group having any substituent or an unsubstituted naphthyl group. 
 
     
     
         6 . The preventing or ameliorating agent for pigmentation according to  claim 5 , wherein in the general formula (2);
 R 4  is the unsubstituted aromatic group or the aromatic group having the substituent which is a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 6, an alkoxy group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, an alkylamino group having a linear or branched alkyl chain or chains having a number of carbon atom or atoms of 1 to 6, an acyl group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, an ester group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, a halogen atom, a halogenated alkyl group, a hydroxy group, or an amino group (provided that unsubstituted phenyl group is excluded);   R 5  is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an acetyl group, a propionyl group, or a butylyl group;   R 6  is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a tert-butyl group; and   at least one of R 5  and R 6  is any group other than the hydrogen atom when R 4  is the phenyl group having the substituent or the unsubstituted naphthyl group.   
     
     
         7 . The preventing or ameliorating agent for pigmentation according to  claim 6 , wherein in the general formula (2);
 R 4  is a phenyl group having the substituent which is a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 6, an alkoxy group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, an alkylamino group having a linear or branched alkyl chain or chains having a number of carbon atom or atoms of 1 to 6, an acyl group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, an ester group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, a halogen atom, a halogenated alkyl group, a hydroxy group, or an amino group, an unsubstituted naphthyl or biphenyl group, or a naphthyl or biphenyl group having the substituent as defined above;   R 5  is a hydrogen atom, a methyl group, or an acetyl group;   R 6  is a hydrogen atom, a methyl group, or an ethyl group; and   at least one of R 5  and R 6  is any group other than the hydrogen atom when R 4  is the phenyl group having the substituent or the unsubstituted naphthyl group.   
     
     
         8 . An external preparation for skin, containing the preventing or ameliorating agent for pigmentation as defined in any one of  claims 5  to  7 . 
     
     
         9 . The external preparation for skin according to  claim 8 , wherein 0.0001% by mass to 20% by mass of the preventing or ameliorating agent for pigmentation is contained with respect to a total amount of the external preparation for skin. 
     
     
         10 . The external preparation for skin according to  claim 8 , wherein the external preparation for skin is a cosmetic preparation (provided that quasi-pharmaceutical products or quasi-drugs are included). 
     
     
         11 . A compound represented by the following general formula (2), an isomer thereof, and/or a pharmacologically acceptable salt thereof: 
       
         
           
           
               
               
           
         
       
       wherein:
 R 4  represents an unsubstituted aromatic group or an aromatic group having any substituent (provided that unsubstituted phenyl group is excluded); 
 R 5  represents a hydrogen atom, a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 4, or an acyl group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 4; 
 R 6  represents a hydrogen atom or a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 4; and 
 at least one of R 5  and R 6  is any group other than the hydrogen atom when R 4  is a phenyl group having any substituent or an unsubstituted naphthyl group. 
 
     
     
         12 . The compound according to  claim 11 , wherein in the general formula (2);
 R 4  is the unsubstituted aromatic group or the aromatic group having the substituent which is a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 6, an alkoxy group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, an alkylamino group having a linear or branched alkyl chain or chains having a number of carbon atom or atoms of 1 to 6, an acyl group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, an ester group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, a halogen atom, a halogenated alkyl group, a hydroxy group, or an amino group (provided that unsubstituted phenyl group is excluded);   R 5  is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an acetyl group, a propionyl group, or a butylyl group;   R 6  is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a tert-butyl group; and   at least one of R 5  and R 6  is any group other than the hydrogen atom when R 4  is the phenyl group having the substituent or the unsubstituted naphthyl group.   
     
     
         13 . The compound according to  claim 12 , wherein in the general formula (2);
 R 4  represents a phenyl group having the substituent which is a linear chain or branched chain alkyl group having a number of carbon atom or atoms of 1 to 6, an alkoxy group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, an alkylamino group having a linear or branched alkyl chain or chains having a number of carbon atom or atoms of 1 to 6, an acyl group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, an ester group having a linear or branched alkyl chain having a number of carbon atom or atoms of 1 to 6, a halogen atom, a halogenated alkyl group, a hydroxy group, or an amino group, an unsubstituted naphthyl or biphenyl group, or a naphthyl or biphenyl group having the substituent as defined above;   R 5  represents a hydrogen atom, a methyl group, or an acetyl group;   R 6  represents a hydrogen atom, a methyl group, or an ethyl group; and   at least one of R 5  and R 6  is any group other than the hydrogen atom when R 4  is the phenyl group having the substituent or the unsubstituted naphthyl group.