Inhibitory Mechanism of Quercimeritrin as a Novel -Glucosidase Selective Inhibitor

In this study, 12 flavonoid glycosides were selected based on virtual screening and the literature, and Quercimeritrin was selected as the best selective inhibitor of alpha-glucosidase through in vitro enzyme activity inhibition experiments. Its IC50 value for alpha-glucosidase was 79.88 mu M, and its IC50 value for alpha-amylase >250 mu M. As such, it could be used as a new selective inhibitor of alpha-glucosidase. The selective inhibition mechanism of Quercimeritrin on the two starch-digesting enzymes was further explored, and it was confirmed that Quercimeritrin had a strong binding affinity for alpha-glucosidase and occupied the binding pocket of alpha-glucosidase through non-covalent binding. Subsequently, animal experiments demonstrated that Quercimeritrin can effectively control postprandial blood glucose in vivo, with the same inhibitory effect as acarbose but without side effects. Our results, therefore, provide insights into how flavone aglycones can be used to effectively control the rate of digestion to improve postprandial blood glucose levels.