Rapid Screening of Lipase Inhibitors From <i>Chrysanthemum</i> Based on Ionic Liquid/Chitosan Bifunctionalized Magnetic Multi‐Walled Carbon Nanotubes Immobilized Lipase

In this study, a novel ionic liquid/chitosan bifunctionalized magnetic multi-walled carbon nanotubes composite material (m-MWCNTs@CS@IL) was utilized for the first time to immobilize lipase. The immobilized lipase exhibited exceptional stability and reusability, as evidenced by its characteristic properties. A ligand fishing approach utilizing the immobilized lipase was developed to enable rapid screening of lipase inhibitors from Chrysanthemum. Three ligands were successfully screened from Chrysanthemum and then identified as cynaroside, quercitrin, and linarin by ultra-high performance liquid chromatography-tandem mass spectrometry. The IC₅₀ values of these three ligands were 76.77 ± 0.36, 83.01 ± 0.46, and 43.61 ± 0.77 µM, respectively. Furthermore, molecular docking analysis further confirmed the binding of three ligands to specific amino acid residues within the active site of lipase. This work presents a fast and efficient approach for screening lipase inhibitors from intricate natural sources, demonstrating promising prospects in discovering anti-obesity compounds.