Rosmarinic acid separation from Perilla frutescens leaf extract utilizing acid-resistant magnetic molecularly imprinted polymers with boronate affinity

In this study, an acid-resistant magnetic boron-modified molecularly imprinted polymer (Fe3O4@NH2@BA@Lyz-MIPs) was prepared by the phase transition of lysozyme and used for the selective recognition and separation of rosmarinic acid from Perilla frutescens leaf extract. The synthesized materials were characterized by thermogravimetric analysis (TG), infrared spectroscopy (FT-IR), electron microscopy (SEM), and vibrating sample magnetometry (VSM). The adsorption and desorption experiments, adsorption kinetics experiments, and adsorption thermodynamics experiments revelated that the Fe3O4@NH2@BA@Lyz-MIPs exhibited a better adsorption capacity for rosmarinic acid (6.31 mg/g). Furthermore, Fe3O4@NH2@BA@Lyz-MIPs still exhibit a good adsorption performance after 8 adsorption-desorption cycles. The adsorption capacity decreased by 8.12 %, and the desorption performance decreased to 78.84 %. Stability experiments showed that the prepared imprinted layer was not destroyed by the eluent and could protect the internal magnetic core of the material. In summary, the prepared molecularly imprinted polymer Fe3O4@NH2@BA@Lyz-MIPs has good selective adsorption and high acid stability and can be swiftly retrieved from solution with the aid of an applied magnetic field, which provides a rapid and environmentally friendly strategy for the separation of rosmarinic acid from a complicated matrix. •Fe3O4@NH2@BA@Lyz-MIPs was synthesized for rosmarinic acid separation.•Template molecules were immobilized via the boron affinity principle.•Generation of acid-resistant imprinting layer by lysozyme phase transition.•MIPs obtained show good acid resistance stability and selective adsorption ability.