Core-shell magnetic molecularly imprinted microspheres for selective extraction and determination of Schisandrol A...

A core-shell magnetic surface molecularly imprinted polymer (MIP) was synthesized using chitosan-modified Fe₃O₄ nanoparticles (Fe₃O₄@CS) as the support and Schisandrol A as the template for selective recognition. After optimization of adsorption conditions, static and dynamic binding experiments demonstrated high selectivity toward Schisandrol A, with an imprinting factor of 4.556. Based on this material, a magnetic solid-phase extraction coupled with high-performance liquid chromatography (MSPE-HPLC) method was established for the enrichment and quantitative determination of Schisandrol A in Schisandra chinensis, achieving a limit of detection of 0.59 ng/mL and a limit of quantification of 2.47 ng/mL. The practical applicability of the MIP was further evaluated by selectively depleting Schisandrol A from the herbal extract, followed by assessment of hepatoprotective activity using an ethanol-induced fatty liver zebrafish larva model. Comparative analysis of hepatic lipid accumulation and biochemical markers (AST, ALT, and SOD) revealed that removal of Schisandrol A significantly reduced the hepatoprotective efficacy of the extract, confirming its functional contribution. These results demonstrate that the proposed MIP-based MSPE-HPLC strategy provides a robust analytical tool for selective lignan analysis and enables component-specific functional evaluation in complex herbal systems.