Magnetic ligand fishing using immobilized DPP-IV for identification of antidiabetic ligands in lingonberry extract

In this work, a new magnetic ligand fishing probe for discovery of DPP-IV inhibitory ligands was developed and it was tested as a proof of concept on the fruit extract of Vaccinium vitis-idaea (lingonberry). The ligands were shown to have appreciable dipeptidyl peptidase IV (DPP-IV) inhibitory activity (IC 50 : 31.8 μg mL-1).) Inhibition of DPP-IV is a well-known therapeutic approach for management of type 2 diabetes (T2D). DPP-IV was successfully immobilized onto magnetic beads and was shown to retain its catalytic activity and selectivity over a model mixture. A total of four ligands were successfully fished out and identified as cyanidin-3-galactoside ( 2 ), cyanidin-3-arabinoside ( 3 ), proanthocynidin A ( 4 ), and 10-carboxyl-pyranopeonidin 3- O -(6″- O -p-coumaroyl)-glucoside ( 5 ) using HPLC/HRMS.