A magnetic beads-based ligand fishing method Coupled with UHPLC-QTOF MS for screening and identification of α-glucosidase inhibitors from Houttuynia cordata Thunb

Abstract

In this study, a method for the screening and identification of α-glucosidase inhibitors from natural products was developed. The α-glucosidase was immobilized on carboxyl terminated magnetic beads to form a ligand fishing system to screen the potential inhibitors. A total of 9 compounds were fishing out from the crude Houttuynia cordata Thunb. extract. Meanwhile, ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS) was used for the identification of the chemical structures, including 3 chlorogenic acid isomers, 2 flavone C-glycosides and 4 flavone O-glycosides. The combination of enzyme immobilization magnetic beads and UHPLC-QTOF MS could be used for the screening of bioactive multi-components from herbs with appropriate targets. Taking the advantage of the specificity of enzyme binding and the convenience of magnetic separation, the method has great potential for rapid screening of α-glucosidase inhibitors from complicated natural product extracts.

Keywords: Houttuynia cordata Thunb; Ligand fishing; Magnetic beads; UHPLC-QTOF MS; α-glucosidase inhibitor.