Screening of lipase inhibitors in citrus fruits by electrophoretically - mediated microanalysis combined with molecular docking

An efficient and environmentally friendly method for the online screening of lipase inhibitors by capillary electrophoresis was established to investigate the inhibitory activity of citrus flavonoids. To maintain high lipase activity during the experiment, the type, concentration and pH value of the running buffer were optimized. At the same time, the enzymatic reaction time was optimized to ensure sufficient product formation. Under the optimized conditions, the Michaelis-Menten constant (Km) of lipase was determined to be 1.345 mM, and the half-maximal inhibitory concentration (IC50) and inhibition constant (Ki) of orlistat were measured to be 0.1059 and 0.0607 μM, respectively. Then, the developed method was applied to evaluate the inhibitory activity of citrus fruit extracts and showed that the extract of Tangerine Pith had the highest inhibitory activity, with an inhibition percentage of 40.67 %. Additionally, molecular docking technology was used to validate these inhibition experiments, indicating that tangeretin, nobiletin, hesperetin and naringenin could affect the activity of lipase by forming hydrogen bonds with lipase. This method can be used as an effective method for the preliminary screening of lipase inhibitors from citrus fruits.