Dual-template molecularly imprinted polymers based on dopamine-modified porous cellulose for simultaneous enrichment of oleanolic acid and ursolic acid from lingonberries

Ursolic acid (UA) and oleanolic acid (OA) are among the most commonly utilized natural products for liver protection and anti-hepatitis applications, and are also prevalent ingredients in skincare formulations. In this study, cellulose-based molecularly imprinted polymers (MCC/PDA-OA/UA-MIPs) were synthesized using surface molecular imprinting technology, wherein OA and UA bimodal template molecules were incorporated onto the surface of polydopamine-modified cellulose microspheres. The MCC/PDA-OA/UA-MIPs exhibited specific recognition ability towards OA and UA via the complementary imprinted cavities, thereby achieving simultaneous enrichment of both compounds. Characterization and adsorption evaluations revealed that the MCC/PDA-OA/UA-MIPs possessed a uniform shape, good stability, and selective adsorption properties; the maximum adsorption capacities for UA and OA reached 48.26 ± 1.97 mg g −1 and 38.06 ± 1.55 mg g −1 , respectively. The enrichment efficiencies of OA and UA from lingonberry crude extract reached 62.12% and 68.46%. Overall, the MCC/PDA-OA/UA-MIPs developed in this work feature high enrichment efficiency and enhanced sustainability, providing a feasible alternative strategy for the targeted extraction of natural products.