Efficient Separation of Aristolochic Acid I from Caulis Aristolochiae Manshuriensis (Guan-Mu-Tong) with Copper Mediated Magnetic Molecularly Imprinted Polymer

Screening bioactive compounds from natural products is one of the most effective ways for new drug research and development. However, obtaining a single extract component on a large scale and with high purity from a complex matrix is still an arduous and challenging task. Herein, one metal mediated magnetic molecularly imprinted polymer (mMIP) was rationally designed and prepared for specifically capturing Aristolochic acid I (AAI). The preparation was done with copper(II) as binding pivot, (3-aminopropyl) triethoxysilane as functional monomer, and FeO as core, by a one-step sol-gel method. Under the optimized conditions, the apparent maximum binding amount of copper mediated mMIP (Cu-mMIP) reaches as high as 349.72 mg g, the highest among the reported AAI-MIPs. Moreover, the nanoparticles exhibit excellent specificity and selectivity, good reproducibility and stability, high superparamagnetism (60.32 emu g), and high imprinting efficiency (an imprinting factor of 7). By simulating an industrial-scale separation, 16.56 mg AAI (purity of 95.11%) is obtained after six cycles with 100 mg nanoparticles from 20 g (Guan-mu-tong). Notably, this takes only 3 hours and consumes 50 mL of methanol. The study provides a potent tool for the green, fast, and specific extraction of high-purity ingredients from natural plants in the manufacturing industry and conventional analysis in the lab.