Conformations of erythritol and L-threitol in aqueous solution in relation to sweetness properties: a molecular dynamics simulation

Abstract

Erythritol and L-threitol in aqueous solution have been studied by molecular dynamics simulation. Computed NMR proton–proton coupling parameters agree fairly well with published experimental results. The analysis of the mean conformations of both polyalcohols shows that in both compounds it is possible to identify the sweetness triangle characteristic of substances capable of stimulating the sensation of a sweet taste. A close look into the mean structure suggests that erythritol should be a better sweetener than L-threitol. The hydration structure and dynamics were studied, analysing the mean orientation of water molecules through angular distribution functions and hydrogen-bond lifetimes. The water surrounding the solute exhibits, in both cases, higher mobility as measured by comparison of the average lifetimes of hydrogen bonds between water and the polyalcohols with those of bulk water–water hydrogen bonds.