Abstract
Trehalose is a disaccharide that attracts much attention as a stress protectant. In this study, we investigated the interaction between trehalose and benzene compounds. The solubility of benzene compounds increased by the addition of trehalose. Trehalose increased the fluorescence intensity of benzene and p-cresol. The spin-lattice relaxation times (T_1) of ^1H and ^<13>C NMR spectra were measured to investigate the interaction between trehalose and benzene. The T_1 values for the ^1H signals assigned to benzene proton, decrease with increasing concentration of trehalose and the changes reaches plateaus at integer ratios of trehalose to benzene. On the other hand, from the ^<13>C-T_1 measurements for trehalose, the T_1 values of the C-2(C-2') and C-6'(C-6) are found to remarkably change by addition of benzene. ^1H-^1H NOESY measurement for a mixture of trehalose and benzene provide direct evidence for the interaction between the C6'(C-6) and C2(C2') sites of the sugar and the double bonds of benzene. Computer modeling study indicates that trehalose forms a stable complex with a benzene double bond though OH…π and CH…O types of hydrogen bonding. Therefore, these results indicate that one trehalose molecule stoichiometrically interacts with benzene compounds.
