13C NMR measurements of acid-base equilibrium constants in alkaline aqueous solutions of D-glucose anomers.

The concentration dissociation constants p K _c of the α and β D-glucose anomers were measured at pH 12–14 by the ¹³C NMR method. The p K _c values for L ⇔ H₋₁L + H equilibria at 25°C and an ionic strength of 1.0 mol/l (NaCl) were p K = 12.31 ± 0.03 and p K = 12.03 ± 0.01. Dissociation was found to shift all the spectrum lines downfield. The most probable hydroxyl group responsible for the dissociation of β-D-glucose was determined. [ABSTRACT FROM AUTHOR]