Natural alpha-glucosidase inhibitors rapid fishing from Cyperus rotundus using immobilized enzyme affinity screening combined with UHPLC-QTOF MS

An efficient and rapid affinity-based screening method for directly fishing out natural alpha-glucosidase inhibitors from Cyperus. rotundus extract by using immobilized enzyme technology combined with UHPLC-QTOF MS analysis was established. As a results, without time-consuming and laborious isolation workload and false positive interference, five natural alpha-glucosidase inhibitors were successfully recognized and identified from only 400 uL of C. rotundus extracts within only a couple of hours, which suggested that the screening method was rapid, economical, sensitive and feasible. In addition, the captured compounds were isolated and characterized as stilbenoids oligomers, and were proved to be strong alpha-glucosidase inhibitors by inhibitory assay in vitro. Among them, 3 stilbenoids trimers were reported to be potent α-glucosidase inhibitors for the first time. This method could be modified and have the potential for rapidly screening of active compounds extracts against some new targets by immobilizing some other biomacromolecules.