Molecular Approach to the Synergistic Effect on Astringency Elicited by Mixtures of Flavanols

The interactions between salivary proteins and wine flavanols (catechin, epicatechin, and mixtures thereof) have been studied by HPLC-DAD, isothermal titration microcalorimetry, and molecular dynamics simulations. Chromatographic results suggest that the presence of these flavanol mixtures could, facilitate the formation of precipitates to the detriment, of soluble aggregates. Comparison between the thermodynamic parameters obtained showed remarkably higher negative values of Delta G in the system containing the mixture of both flavanols in comparison to the systems containing individual flavanols, indicating a more favorable-scenario in mixing system. Also, the apparent binding constants were higher, in this System. Furthermore) molecular dynamics simulations suggested a faster and greater cooperative binding of catechin and, epicatechin to IB7(14) peptides when both types of flavanols are present simultaneously in solution.