Polysaccharide derivative and separating agent for optical isomer containing the same

Abstract

The present invention provides: a polysaccharide derivative containing a structure wherein hydrogen atoms in a hydroxyl group or amino group at the 2-position and the 3-position of a structure unit of polysaccharide are substituted with different substituents respectively represented by a specific general formula; and, a separating agent for optical isomers, which contains such a polysaccharide derivative. The present invention can provide a novel polysaccharide derivative which has excellent optical isomer separating ability, and is thus suitable for a separating agent for optical isomers, and can provide a separating agent for optical isomers which comprises the polysaccharide derivative.

1 . A polysaccharide derivative, comprising a structure in which hydrogen atoms of at least hydroxyl groups or amino groups at 2- and 3-positions out of hydroxyl groups or amino groups of structural units of a polysaccharide are substituted with different substituents each represented by any one of the following general formulae (I) to (III):
   —CO—R  (I)     —CO—NH—R  (II)     —R  (III)   
     where R represents an aliphatic or aromatic hydrocarbon group which may contain a heteroatom, and the group may further have a substituent. 
   
   
       2 . The polysaccharide derivative according to  claim 1 , wherein the polysaccharide derivative comprises: a structure in which the hydrogen atoms of the hydroxyl groups or amino groups at the 2-positions in the structural units are each substituted with a substituent represented by the general formula (I); and a structure in which the hydrogen atoms of the hydroxyl groups or amino groups at the 3-positions in the structural units are each substituted with a substituent represented by the general formula (II). 
   
   
       3 . The polysaccharide derivative according to  claim 1 , wherein the polysaccharide derivative comprises: a structure in which the hydrogen atoms of the hydroxyl groups or amino groups at the 2-positions in the structural units are each substituted with a substituent represented by the general formula (II); and a structure in which the hydrogen atoms of the hydroxyl groups or amino groups at the 3-positions in the structural units are each substituted with a substituent represented by the general formula (II). 
   
   
       4 . (canceled) 
   
   
       5 . The polysaccharide derivative according to  claim 2 , wherein:
 the structural units each are a hexose further having a hydroxyl group or amino group at its 6-position; and   the polysaccharide derivative further comprises a structure in which a hydrogen atom of the hydroxyl group or amino group at the 6-position in each of the structural units is substituted with a substituent represented by the general formula (II).   
   
   
       6 . The polysaccharide derivative according to  claim 5 , wherein the polysaccharide derivative comprises a structure in which hydrogen atoms of the hydroxyl groups or amino groups at the 3- and 6-positions in the structural units are substituted with two kinds of substituents each represented by the general formula (II). 
   
   
       7 . The polysaccharide derivative according to  claim 5 , wherein the polysaccharide derivative comprises a structure in which hydrogen atoms of the hydroxyl groups or amino groups at the 3- and 6-positions in the structural units are each substituted with one kind of substituent represented by the general formula (II). 
   
   
       8 . The polysaccharide derivative according to  claim 5 , wherein the polysaccharide derivative comprises a structure in which hydrogen atoms of the hydroxyl groups or amino groups at the 3- and 6-positions in the structural units are irregularly substituted with two or more kinds of substituents each represented by the general formula (II). 
   
   
       9 . The polysaccharide derivative according to  claim 23 , wherein the polysaccharide derivative comprises a structure in which hydrogen atoms of the hydroxyl groups or amino groups at the 2- and 6-positions in the structural units are each substituted with one kind of substituent represented by the general formula (II). 
   
   
       10 . The polysaccharide derivative according to  claim 23 , wherein the polysaccharide derivative comprises a structure in which hydrogen atoms of the hydroxyl groups or amino groups at the 2- and 6-positions in the structural units are substituted with two kinds of substituents represented by the general formula (II). 
   
   
       11 . The polysaccharide derivative according to  claim 1 , wherein the polysaccharide is amylose. 
   
   
       12 . A method of producing a polysaccharide derivative, comprising the steps of:
 modifying a hydroxyl group or amino group at a 2-position of each of structural units of a polysaccharide with a first substituent represented by any one of the following general formulae (I) to (III); and   modifying a hydroxyl group or amino group at a 3-position of the structural unit with a second substituent represented by any one of the following general formulae (I) to (III) and different from the first substituent;
   —CO—R  (I) 
   —CO—NH—R  (II) 
   —R  (III) 
   
     where R represents an aliphatic or aromatic hydrocarbon group which may contain a heteroatom, and the group may further have a substituent. 
   
   
       13 . The method according to  claim 12 , wherein the first substituent is a substituent represented by the general formula (I). 
   
   
       14 . The method according to  claim 12 , wherein:
 the structural units each are a hexose further having a hydroxyl group or amino group at its 6-position; and   the method further comprises the step of protecting the hydroxyl group or amino group at the 6-position with a protective group after modifying the hydroxyl group or amino group at the 2-position.   
   
   
       15 . The method according to  claim 14 , further comprising the steps of:
 removing the protective group at the 6-position after modifying the hydroxyl group or amino group at the 3-position; and   modifying the hydroxyl group or amino group at the 6-position from which the protective group has been removed with a third substituent represented by any one of the general formulae (I) to (III) and different from the second substituent.   
   
   
       16 . A method of producing a polysaccharide derivative, comprising:
 a 2-position protecting step of protecting a hydroxyl group or amino group at a 2-position of each of structural units of a polysaccharide with a protective group;   a 3-position modifying step of modifying a hydroxyl group or amino group at a 3-position of the structural unit the 2-position of which has been protected with a second substituent represented by any one of the following general formulae (I) to (III);   a 2-position deprotecting step of removing the protective group at the 2-position in the structural unit the 3-position of which has been modified; and   a 2-position modifying step of modifying the hydroxyl group or amino group at the 2-position from which the protective group has been removed with a first substituent represented by the same general formula as the general formula of the second substituent but different from the second substituent:
   —CO—R  (I) 
   —CO—NH—R  (II) 
   —R  (III) 
   
     where R represents an aliphatic or aromatic hydrocarbon group which may contain a heteroatom, and the group may further have a substituent. 
   
   
       17 . The method according to  claim 16 , wherein:
 the structural units each are a hexose further having a hydroxyl group or amino group at its 6-position; and   the 3-position modifying step is a step of modifying each of the hydroxyl groups or amino groups at both the 3- and 6-positions of the structural units with the second substituent.   
   
   
       18 . The method according to  claim 17 , wherein:
 the 2-position deprotecting step is a step of removing both the protective group at the 2-position and the second substituent at the 6-position; and   the 2-position modifying step is a step of modifying each of the hydroxyl groups or amino groups at both the 2- and 6-positions of the structural units with the first substituent.   
   
   
       19 . The method according to  claim 16 , wherein the first and second substituents each are a substituent represented by the general formula (II). 
   
   
       20 . The method according to  claim 16 , wherein:
 the structural units each are a hexose further having a hydroxyl group or amino group at its 6-position;   the method further comprises
 a 6-position protecting step of protecting the hydroxyl group or amino group at the 6-position of the structural unit, the 2-position of which has been protected, with a protective group before the 3-position modifying step, 
 a 6-position deprotecting step of deprotecting the protective group at the 6-position in the structural unit the 3-position of which has been modified in the 3-position modifying step before the 2-position deprotecting step, and 
 a 6-position modifying step of modifying the hydroxyl group or amino group at the 6-position from which the protective group has been removed with a third substituent represented by the same general formula as the general formula of each of the first and second substituents but different from the first and second substituents; and 
   the 2-position deprotecting step is a step of removing the protective group at the 2-position in the structural unit the 6 position of which has been modified.   
   
   
       21 . The method according to  claim 20 , wherein the first, second, and third substituents each are a substituent represented by the general formula (II). 
   
   
       22 . A separating agent for optical isomers, comprising the polysaccharide derivative according to  claim 1 . 
   
   
       23 . The polysaccharide derivative according to  claim 3 , wherein:
 the structural units each are a hexose further having a hydroxyl group or amino group at its 6-position; and   the polysaccharide derivative further comprises a structure in which a hydrogen atom of the hydroxyl group or amino group at the 6-position in each of the structural units is substituted with a substituent represented by the general formula (II).   
   
   
       24 . The polysaccharide derivative according to  claim 23 , wherein the polysaccharide derivative comprises a structure in which hydrogen atoms of the hydroxyl groups or amino groups at the 3- and 6-positions in the structural units are substituted with two kinds of substituents each represented by the general formula (II). 
   
   
       25 . The polysaccharide derivative according to  claim 23 , wherein the polysaccharide derivative comprises a structure in which hydrogen atoms of the hydroxyl groups or amino groups at the 3- and 6-positions in the structural units are each substituted with one kind of substituent represented by the general formula (II).