Conversion of sugars to ionic liquids

Abstract

Disclosed herein are methods for preparing sugar compositions. The methods include: i) forming a mixture including polysaccharide biomass and an ionic liquid solution, wherein the ionic liquid solution contains water and an ionic liquid, and the ionic liquid contains a) a cation and b) a sugar acid anion or a ketoacid anion; ii) maintaining the mixture under conditions sufficient to dissolve at least a portion of the polysaccharide present in the polysaccharide biomass; iii) adding at least one glycoside hydrolase to the mixture; and iv) maintaining the mixture containing the glycoside hydrolase under conditions sufficient to hydrolyze at least a portion of the dissolved polysaccharide, thereby forming the sugar compositions. The sugar compositions contain at least one monosaccharide or oligosaccharide. New sugar-based ionic liquids are also described.

What is claimed is: 
     
         1 . An ionic liquid comprising at least one anion and at least one cation, wherein the anion is selected from the group consisting of a sugar acid anion and a ketoacid ion. 
     
     
         2 . The ionic liquid of  claim 1 , wherein the sugar acid is selected from the group consisting of an aldaric acid, an aldonic acid, a uronic acid, or a combination thereof. 
     
     
         3 . The ionic liquid of  claim 1 , wherein the sugar acid is selected from the group consisting of mucic acid, saccharic acid, xylaric acid, arabinaric acid, and mannaric acid. 
     
     
         4 . The ionic liquid of  claim 1 , wherein the ketoacid is selected from the group consisting of α-ketoglutaric acid, pyruvic acid, and levulinic acid. 
     
     
         5 . The ionic liquid of  claim 1 , wherein the anion is selected from the group consisting of a mucic acid anion, a mucic acid anion, an α-ketoglutaric acid anion, and an α-ketoglutaric acid dianion. 
     
     
         6 . The ionic liquid of  claim 1 , wherein the cation is selected from choline, (C 1-18  alkyl) 3 NH + , (C 1-6  alkyl) x (C 6-18  alkyl) y N + , (C 1-10  alkyl) z imidazolium, (C 1-18 alkyl) z pyrazolium, and mixtures thereof; wherein subscript x and subscript y are each 0, 1, 2, 3, or 4, and the sum of x and y is 4; and wherein each subscript z is 1, 2, or 3. 
     
     
         7 . The ionic liquid of  claim 6 , wherein the cation is choline.