Behind resveratrol stabilization by carboxymethylated (1,3/1,6)-?-D-glucan: Does the polyphenol play a role in polymer structural organization?

Resveratrol stability in solution can be improved by combining the polyphenol with carboxymethylated (1,3/1,6)-?-D-glucan (CM-glucan), a carbohydrate polymer widely used in the food and pharmaceutical industries. The present work was undertaken to elucidate the mechanism behind this stabilizing effect. The supramolecular structural, physico-chemical and morphological features of the CM-glucan/resveratrol complex have been studied under different physical and chemical stimuli by means of spectroscopic techniques, microscopy and physical methods such as UV-Visible spectroscopy (UV-Vis), spectrofluorimetry, Circular Dichroism (CD), Infrared spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). Our experimental data indicate that CM-glucan conformational organized architecture in aqueous solution is enhanced in the presence of resveratrol, suggesting that the polyphenol is able to confer a high degree of order to the polymer by a probable cooperative structural organization that results in a long term stabilization for the polyphenol.