Construction of Molecularly Imprinted Polymer Based on Multiple Affinity Strategies for the Enrichment of Dihydromyricetin From Vine Tea

A dihydromyricetin molecularly imprinted polymer was fabricated via a multi-affinity synergistic strategy. Specifically, the deep eutectic solvent (choline chloride/methacrylic acid at molar ratio of 1:2) served as a non-covalent functional monomer, interacting with dihydromyricetin via hydrogen bonds, 3-acrylamidophenylboronic acid acted as a covalent functional monomer to form boronate affinity covalent bonds with dihydromyricetin, and zinc acrylate formed boronate affinity interactions with dihydromyricetin. The synergistic integration of these three components endowed the polymer with a ternary recognition site simultaneously capable of hydrogen bonding, boronate affinity, and metal chelation. After polymerization, the as-prepared dihydromyricetin molecularly imprinted polymer was characterized by scanning electron microscope, energy dispersive spectrometer, Fourier-transform infrared spectrometer, thermal gravimetric analysis, and x-ray photoelectron spectrum. The effects of imprinting conditions, pH of incubation solution, adsorbent amount, selectivity, stability and reusability of dihydromyricetin molecularly imprinted polymer were also investigated. Under optimal adsorption conditions, the maximum adsorption capacity was calculated to be 359.04 mg/g in 240 min, and the imprinted factor was 1.40, aligned better fitted with Freundlich model and pseudo-second-order kinetic model. The better selectivity of dihydromyricetin molecularly imprinted polymer for dihydromyricetin in the presence of other structurally related compounds indicated its robust anti-interference capability. Furthermore, the dihydromyricetin molecularly imprinted polymer was employed as an adsorbent for the selective extraction of dihydromyricetin from vine tea, with the enrichment efficiency from 68.82% to 70.38%. These results demonstrated that the synergistic imprinting strategies could enhanced the affinity of dihydromyricetin molecularly imprinted polymer toward dihydromyricetin, offering a promising approach for the separation and purification of dihydromyricetin from natural products.