Hollow fiber based affinity selection combined with high performance liquid chromatography-mass spectroscopy for rapid screening lipase inhibitors from lotus leaf.

A novel kind of immobilized enzyme affinity selection strategy based on hollow fibers has been developed for screening inhibitors from extracts of medicinal plants. Lipases from porcine pancreas were adsorbed onto the surface of polypropylene hollow fibers to form a stable matrix for ligand fishing, which was called hollow fibers based affinity selection (HF-AS). A variety of factors related to binding capability, including enzyme concentration, incubation time, temperature, buffer pH and ion strength, were optimized using a known lipase inhibitor hesperidin. The proposed approach was applied in screening potential lipase bound ligands from extracts of lotus leaf, followed by rapid characterization of active compounds using high performance liquid chromatography-mass spectrometry. Three flavonoids including quercetin-3-O-β-D-arabinopyranosyl-(1→2)-β-D-galactopyranoside, quercetin-3-O-β-D-glucuronide and kaempferol-3-O-β-d-glucuronide were identified as lipase inhibitors by the proposed HF-AS approach. Our findings suggested that the hollow fiber-based affinity selection could be a rapid and convenient approach for drug discovery from natural products resources.