Investigation of Resveratrol Adsorption on Pine Pollen Grains: A First-Principles Study

Pollen grains have been successfully used as a solid-phase extraction sorbent to separate trans-resveratrol (TRA) in peanut oils. The interactions between TRA and polyphenolic compounds including kaempferol, taxifolin, dihydrokaempferol and naringenin in pollen grains are investigated by first-principles calculations with M06-2X functional. The adsorption ability of TRA is the strongest on kaempferol in the studied systems. Interaction analysis indicates that there are pi-pi interaction and hydrogen bonds during the adsorption. The structure of the polyphenolic compound determines the adsorption ability. The more planar of the structure and the higher number of hydroxyl group in the polyphenolic compound, the better adsorption of the compound for TRA. Moreover, the investigation of solvent effects illustrates that with the increase in the dielectric constant of the solvent, the stability of the adsorption system improves and the adsorption ability weakens. The results play a significant role in developing new excellent solid-phase extraction sorbents for TRA.