Ab initio investigation of the first hydration shell of glucose

The interaction between sugars and water molecules plays a crucial role in exploring the complex metabolic reactions of living systems. The fully random conformational search is employed to investigate the first hydration shell structure of glucose. The circumference of glucose is divided into three hydrate sites according to the location of water molecules. Especially, four water molecules can saturate hydrate site A_I and while more water molecules will be required to saturate hydrate sites A_III and A_II. Moreover, the hydration energies of water molecules at different hydration region indicate that the competition of the three hydrate sites for water molecules changes dynamically with the increase of water molecules. In addition, we calculate the Raman spectra of the hydrated glucose, which are in good agreement with the experimental and theoretical Raman spectra of the glucose solution.