DFT study of the physicochemical properties of A- and B-type procyanidin oligomers

Abstract

The objective of this study was to determine the physicochemical properties of the oligomers of procyanidins (PCs) including PA1, PA2, PB1, PB2, PC1 and a B-type tetramer, taking into account of their conformations related to the interflavan links using the density functional theory (DFT). This information may provide useful insight into the potential effect of physicochemical properties on the absorption of PCs. The results indicate that A-type and B-type PCs in all of their conformations tend to be more stable in water than in octanol, showing a hydrophilic character due to their negative log [Formula: see text] values, which increase with the degree of polymerization (DP). The studied PCs, including the B-type tetramer, can achieve an appropriate molecular size (i.e. width and length) that can allow them to pass through the pores in the paracellular route in the human small intestine. The factor that could limit the absorption of the PC oligomers with increases in size is the higher number of hydroxyl groups exposed to the outside of the molecule due to their potential to interact with other molecules, which is based on electrostatic potential maps.