NMR and quantum chemical study on the OH...π and CH...O interactions between Trehalose and unsaturated fatty acids: Implication for the mechanism of antioxidant function of Trehalose

Trehalose is a disaccharide that attracts much attention as a stress protectant. In this study, we investigated the mechanism of the antioxidant function of trehalose. The spin−lattice relaxation times (T1) of 1H and 13C NMR spectra were measured to investigate the interaction between trehalose and unsaturated fatty acid (UFA). We selected several kinds of UFA that differ in the number of double bonds and in their configurations (cis or trans). Several other disaccharides (sucrose, maltose, neotrehalose, maltitol, and sorbitol) were also analyzed by NMR. The T1 values for the 1H and 13C signals assigned to the olefin double bonds in UFA decrease with increasing concentration of trehalose and the changes reaches plateaus at integer ratios of trehalose to UFA. The characteristic T1 change is observed only for the combination of trehalose and UFA with cis double bond(s). On the other hand, from the 13C−T1 measurements for trehalose, the T1 values of the C-3 (C-3‘) and C-6‘ (C-6) are found to change remarkabl...