Online coupling FeO@ZIF-67@α-glucosidase biomicroreactor with high performance liquid chromatography for rapid screening of α-glucosidase inhibitors in tea and their inhibitory activity research.

In this work, α-glucosidase was immobilized on a type of nanoscaledmagnetic materials FeO@ZIF-67 to construct a biomicroreactor for rapid screening α-glucosidase inhibitors. The parameters that affected the immobilization efficiency were investigated. Under optimal conditions, the amount of α-glucosidase loaded was up to 79.07 μg·mg. Then, the enzyme biomicroreactor was immobilized by an external magnetic field in a tube connecting HPLC and micro-injection pump at both ends to form a magnetic online screening system. The screening flow rate and eluent organic solvent ratio during the screening process were optimized. XinYang MaoJian crude tea extract was tested to verify this online screening method, and three inhibitors (catechin, epigallocatechin gallate and epicatechin gallate) were fished by this magnetic online screening system. Based on the classical pNPG method, the inhibitory activities on α-glucosidase were further verified and studied. Compared with the traditional ligand fishing methods, the screening method established in this work can integrate screening, elution and analysis. It can simply, efficiently and directly screen and identify potential α-glucosidase inhibitors from natural sources. This method was expected to provide an effective basis for accelerating the development of new hypoglycemic drugs.