Online bioactivity-guided HPLC-lipoprotein lipase system with medium-high pressure chromatography for rapid recognition and targeted isolation of natural affinity agents from Nitraria tangutorum

In this study, we developed an online HPLC-lipoprotein lipase system capable of directly recognizing chromatographic peaks corresponding to lipoprotein lipase affinity agents from Nitraria tangutorum . Notably, using the HPLC-lipoprotein lipase system, six lipoprotein lipase affinity agents were successfully recognized and isolated with purities > 95 %, including one phenylpropanoid, one apigenin, and four quercetin derivatives. In vitro enzymatic assays and molecular docking studies demonstrated that these glycosylated compounds bind effectively to the active site of lipoprotein lipase, with binding energies ranging from -7.2 to -8.8 kcal/mol. The compounds also showed notable affinity, with median inhibitory concentration values between 56.2 μM and 202.3 μM and half-maximal effective concentration values ranging from 106.8 μM to 311.0 μM. These results suggest that quercetin glycosides in Nitraria tangutorum contribute significantly to the regulation of lipoprotein lipase activity. Importantly, the established online HPLC-lipoprotein lipase recognition system demonstrated broad application prospects, particularly by providing a rapid and high-precision method for discovering lipoprotein lipase affinity agents in chemically complex natural products.