Remarkably strong, uncharged hydrogen-bonding interactions of polypyridine-macrocyclic receptors for deoxyribofuranosides

Novel macrocyclic saccharide receptors that possess a pyridine-pyridone-pyridine arrangement as a hydrogen-bonding motif are presented. The artificial receptors exhibited a remarkably strong binding affinity for deoxyribofuranoside derivatives in CDCl3 (K-a = 19 000 M-1 -Delta G(298) = 24.4 kJ/mol), one of the highest values of artificial receptors having only uncharged hydrogen-bonding sites for monosaccharide derivatives. Selective extraction of deoxyribose by the receptors was also observed; the extractabilities,;or affinities to the receptors of various pentoses and hexoses, decreased in the following order: deoxyribose > lyxose congruent to ribose > arabinose congruent to fructose congruent to xylose > glucose > mannose > galactose.