Crystalline carbohydrate derivative

Abstract

α-Lactosamine hydrochloride, substantially free of β-lactosamine hydrochloride; a method of preparing α-lactosamine hydrochloride monohydrate from an anomeric mixture of lactosamine hydrochloride, including: preparing a solution including the anomeric mixture of lactosamine hydrochloride, water and at least one water-miscible organic solvent at a temperature of 0-100° C., and cooling the solution to cause crystallisation of α-lactosamine hydrochloride monohydrate; a method of preparing anhydrous α-lactosamine hydrochloride; and use of α-lactosamine hydrochloride as a food supplement or intermediate in synthesis.

1 . A method of preparing α-lactosamine hydrochloride monohydrate from an anomeric mixture of lactosamine hydrochloride, comprising:
 preparing a solution comprising the anomeric mixture of lactosamine hydrochloride, water and at least one water-miscible organic solvent at a temperature of 0-100° C.; 
 cooling the solution to cause crystallisation of α-lactosamine hydrochloride monohydrate. 
 
     
     
         2 . A method of preparing a-lactosamine hydrochloride monohydrate according to  claim 1 , wherein the solution is prepared by dissolving the anomeric mixture of lactosamine hydrochloride in water at a temperature of 40-100° C., and subsequent addition of the at least one water miscible organic solvent. 
     
     
         3 . A method according to  claim 1 , further comprising the preliminary steps of:
 dissolving the anomeric mixture of lactosamine hydrochloride in water; and   adding the solution to acetone to cause precipitation of a white powder;   wherein the white powder is used as the anomeric mixture in the preparation of the solution of  claim 1 .   
     
     
         4 . A method of preparing of a-lactosamine hydrochloride monohydrate from lactosamine, comprising:
 preparing a solution of lactosamine in aqueous HCl at 40-100° C., which solution further comprises at least one water miscible organic solvent which is an aliphatic alcohol;   cooling the solution to cause crystallization of α-lactosamine hydrochloride monohydrate.   
     
     
         5 . A method according to  claim 1 , wherein the at least one water miscible organic solvent is selected from the group consisting of acetone, tetrahydrofuran, acetonitrile, dioxane, aliphatic alcohols, and 1,2-dimethoxyethane. 
     
     
         6 . A method according to  claim 5 , wherein the at least one water miscible organic solvent is at least one aliphatic alcohol ROH, wherein R is selected from methyl, ethyl, isopropyl, isobutyl and n-butyl. 
     
     
         7 . A method according to  claim 6 , wherein R is isopropyl. 
     
     
         8 . A method according to  claim 1 , wherein the solution is cooled to between −5 and 30° C. in order to cause crystallisation. 
     
     
         9 . A method according to  claim 1 , wherein the solution is stirred during cooling. 
     
     
         10 . A method according to  claim 1 , wherein a seed crystal of α-lactosamine hydrochloride monohydrate is provided during cooling to assist in inducing crystallization. 
     
     
         11 . A method of preparing a lactosamine-containing oligosaccharide, comprising
 a) preparing α-lactosamine hydrochloride substantially free of β-lactosamine hydrochloride, and   b) conversion of the α-lactosamine hydrochloride into a lactosamine-containing oligosaccharide.   
     
     
         12 . A method of preparing a human milk oligosaccharide, comprising
 a) preparing α-lactosamine hydrochloride substantially free of β-lactosamine hydrochloride, and   b) conversion of the α-lactosamine hydrochloride into a human milk oligosaccharide.   
     
     
         13 . A method according to  claim 4 , wherein the alcohol is ROH, wherein R is selected from methyl, ethyl, isopropyl, isobutyl and n-butyl. 
     
     
         14 . A method according to  claim 13 , wherein R is isopropyl. 
     
     
         15 . A method according to  claim 4 , wherein the solution is cooled to between −5 and 30° C. in order to cause crystallisation. 
     
     
         16 . A method according to  claim 4 , wherein the solution is stirred during cooling. 
     
     
         17 . A method according to  claim 4 , wherein a seed crystal of α-lactosamine hydrochloride monohydrate is provided during cooling to assist in inducing crystallization.