Rapid screening of lipase inhibitors from Chrysanthemum indicum L. combining lipase-immobilized polypropylene hollow fibers with LC-MS and molecular networking

Chrysanthemum indicum L. has traditionally been utilized as one of the main ingredients in many functional foods or tea for lipid-lowing by advantages of abundant bioactive components and lower side effects. However, the specific compounds responsible for these beneficial lipid-lowering properties remain unrevealed. In this study, lipase-immobilized hollow fibers were first developed to screen out potential lipase ligands by integrating ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-QTOF-MS/MS) with a molecular networking approach, in which the incorporation of glutaraldehyde as crosslinker achieved a 2.24-fold increase in enzyme loading capacity. The immobilized lipase retained over 50% relative viability after 6 enzymatic cycles or 10 h of storage (4 °C). A total of 30 potential ligands were successfully screened out and identified. Among them, the inhibitory activities and the mechanism of action of three representative candidate ligands (Ethyl chlorogenate, Luteolin 7- O -glucuronide and Ethyl caffeate) were further investigated through in vitro enzyme activity assays and molecular docking analysis. Overall, the current study proposed a promising strategy for the rapid discovery and identification of bioactive compounds against obesity from complex natural extracts in natural foods.