Experimental and theoretical study on the intermolecular complex formation between trehalose and benzene compounds in aqueous solution.

The uniqueness of trehalose as a stress protectant may exist in its potential amphiphilic character capable of interacting with both hydrophilic and hydrophobic partners in aqueous solution. To address this issue, we here investigated the interaction between trehalose and aromatic compounds. NMR measurements, including (1)H-(1)H NOESY spectra, provide direct evidence for the formation of stable intermolecular complexes of trehalose with benzene (or p-cresol) in aqueous solution. In addition, corresponding theoretical evidence is provided by calculating the potential mean force as a function of the distance between trehalose and benzene. In the energy minimum structure, the benzene molecule is located only around the hydrophobic side of trehalose where the first hydration shell is not formed. Therefore, it can be concluded that benzene binds to trehalose in a fashion in which dehydration penalty is minimized. Finally, we discuss the possible biological roles of the trehalose-benzene interaction discovered here.