Influence of chemical structure on the solubility of low molecular weight carbohydrates in room temperature ionic liquids

Abstract

The use of room temperature ionic liquids (ILs) as green solvents is an emerging and innovative technology, which is quickly expanding in carbohydrate chemistry. However, information about solubility of low molecular weight carbohydrates (LMWC) in ILs is still scarce. This study provides new solubility data for several LMWC dissolved in methylimidazolium-based ILs. Different solubility values have been obtained for carbohydrates depending on their structure. In general, ketoses are more soluble than their corresponding aldoses, and trisaccharides are more soluble than mono- and disaccharides, although some exceptions have been observed depending on the tested IL. [BMIM][MeSO4] and [HMIM][Cl] acted both as solvent and as catalyst for dehydration of ketoses (fructose and tagatose) into 5-hydroxymethylfurfural at 318 K. These findings pointed out the potential of ILs as an interesting alternative solvent for new applications in applied carbohydrate chemistry.