Structural studies on natural sweeteners by NMR spectroscopy and computational methods

In the present day, sweet tasting molecules have attracted a lot of attention beingsubject of escalating sugar-related diseases. The molecular recognition of sweet tastingmolecules are known to be highly dependent on their conformation, which is mostlydetermined by non-bonding interactions with surrounding water molecules and thesweet taste receptor. Yet, the interaction of chemoreception at the molecular level stillremains undiscovered. This study aims to elucidate the hydrogen bonding propertiesof selected sweeteners by employing an unconventional NMR spectroscopy method.The computational studies are integrated with experiments, in order to focus on submolecularevents that are assumed to be responsible for the sweet-taste recognition.Our results show distinct hydrogen bonding properties possessed by all the moleculesexamined. The terminal hydroxyl groups show preference to exchange protons withsurrounding water molecules, while internal hydroxy protons tend to form hydrogenbonds. Experimentally observed diastereotopicity of sweet-tasting molecules shows theimportance of geometry in the molecular recognition level.