Competitive transport of reducing sugars through a lipophilic membrane facilitated by aryl boron acids

The extraction and competitive transport of fructose, glucose and sucrose through dichloroethane facilitated by combinations of aryl boron acids and tetraalkyl ammonium salts is described. Although extraction abilities of the boron acids are comparable, there are distinct differences in their sugar transport properties. The aqueous solubility of the aryl boron acid is apparently a critical controlling factor of sugar flux. A combination of PEA and aliquat(R) 336 in the membrane effectively separates fructose from an equimolar mixture of fructose, glucose and sucrose, despite extraction experiments displaying comparable extraction of glucose and fructose. (C) 1997 Elsevier Science Ltd.