Computer-aided fabrication of molecularly imprinted COFs for enantioselective extraction of dihydroquercetin from vine tea.

Efficient separation and enrichment of bioactive flavonoid enantiomers from complex natural matrices remain a major challenge in analytical and life sciences. However, the enantioselectivity of adsorbents for flavonoid extraction remains limited because they lack complementary recognition sites. Herein, molecularly imprinted covalent organic frameworks (MI-COFs) were constructed based on a computer-aided design, which formed well-defined imprinting cavities serving as high-affinity recognition sites. These cavities impart precise and selective recognition toward flavonoid enantiomers, enabling efficient extraction of (2R,3R)-dihydroquercetin (DMY) from vine tea. The MI-COFs exhibited a high adsorption capacity (105 mg/g), excellent selectivity (imprinting factor, 2.7), and rapid adsorption kinetics. The MI-COFs were successfully applied as adsorbents for the targeted extraction of DMY from real vine tea samples, achieving high recoveries (86.8-89.2 %) and an enantiomeric excess of 98 %, with excellent reproducibility. This work demonstrates that rational chiral functionalization of MI-COFs enables precise and selective recognition of target enantiomers. Moreover, it provides a robust and versatile platform for the enantioselective separation and purification of chiral natural products, with broad applicability in food and pharmaceutical analysis.