The specific extraction of glabridin from licorice residues using molecular imprinting technique.

The large-scale production of glycyrrhizic acid inevitably generates a large amount of licorice residues waste, which contains a wealth of active ingredients, especially glabridin, a natural preservative. However, traditional extraction methods for glabridin are often limited by bottlenecks such as time-consuming, inefficient, and insufficient specificity. To overcome these challenges, this study innovatively introduced 2-phenylimidazole as a functional monomer by computer simulations and successfully developed magnetic molecularly imprinted polymers (MMIPs) for glabridin. The adsorption capacity of MMIPs could reach 25.61 mg/g at 300 min, and the MMIPs had high specificity with an imprinting factor of 1.9. In addition, the MMIPs had high selectivity and reproducibility with a selectivity factor of 2.34, and the adsorption capacity could be maintained at 90 % after six times of repeated use. It can increase the purity of glabridin from 20 % to about 77 % in the complex environment of licorice residues, showing good specificity and promising application.