Structural functions of the sweet pharmacophore

Area of Science:

• Carbohydrate Chemistry
• Sensory Science
• Molecular Recognition

Background:

• Understanding the molecular basis of sweetness perception is crucial for food science and drug development.
• Previous models of sweetness, like the tripartite pharmacophore, have been proposed but require further validation with simple sugars.

Purpose of the Study:

• To investigate the structural determinants of sweetness in various sugars.
• To evaluate the role of intramolecular hydrogen bonding and the gamma-function in sugar sweetness.
• To differentiate the mechanisms of sweetness between natural sugars and artificial sweeteners.

Main Methods:

• Assessing the relative sweetness, onset times, and duration of response for D-glucose, D-xylose, D-quinovose, D-galactose, L-arabinose, and D-fucose.
• Conducting these sensory evaluations across four different temperatures.
• Interpreting the data using principles of intramolecular hydrogen bonding.

Main Results:

• The gamma-function of the tripartite sweet pharmacophore appears to play a minimal role in the sweetness of the tested sugars.
• The Lemieux effect, involving intramolecular hydrogen bonding, is likely the dominant factor in determining sugar sweetness.
• Distinct sensory parameters (intensity and time of response) suggest separate chemoreception functions.

Conclusions:

• Intramolecular hydrogen bonding, particularly the Lemieux effect, is key to understanding sugar sweetness.
• The absence of a significant gamma-function in simple sugars like glucose distinguishes them from potent artificial sweeteners.
• Chemoreception for sweetness involves distinct molecular interactions and signaling pathways.