The solution conformation of sucrose: concentration and temperature dependence

Area of Science:

• Carbohydrate Chemistry
• Physical Chemistry
• Biophysical Chemistry

Background:

• Understanding molecular dynamics is crucial for carbohydrate chemistry.
• Aqueous sucrose conformation and motion influence its physical properties and biological interactions.

Purpose of the Study:

• To investigate the molecular motion and conformational stability of sucrose in aqueous solution.
• To elucidate the dynamics of internal rotations within the sucrose molecule.

Main Methods:

• Utilized Carbon-13 Nuclear Magnetic Resonance (13C-N.m.r.) spectroscopy.
• Performed spin-lattice relaxation measurements to probe molecular dynamics.

Main Results:

• Demonstrated anisotropic tumbling of sucrose in solution.
• Found sucrose conformation to be independent of temperature and concentration.
• Identified distinct internal rotation rates and activation energies for the three hydroxymethyl groups.

Conclusions:

• Aqueous sucrose exhibits anisotropic molecular motion.
• Sucrose's conformation is stable and similar to its crystal form, with a loss of one intramolecular hydrogen bond.
• Internal dynamics of hydroxymethyl groups vary significantly.