The bioactivity of prenylated stilbenoids and their structure-activity relationship.

Dietary prenylated stilbenoids present in many food resources, and have good bioactivities. However, their structure-activity relationships are rarely reported. In this work, eighteen C- and O-prenylated stilbenoids were chemically semisynthesized using one-step approach. They all could inhibit sugar digestive enzymes, including α-glucosidase and α-amylase. 4-Geranyl piceatannol from jackfruit showed the strongest activity by suppressing dipeptidyl peptidase-IV (DPP-IV) activity. The enzyme inhibition kinetics were measured and the inhibition mechanism was revealed. Evaluation of antioxidant activity highlighted that the introduction of prenyl with increasing prenyl chain length can significantly increase the antioxidant activity of stilbenoids. Our results suggested that prenylated stilbenoids could be used as functional food additives to decrease postprandial blood sugar levels by inhibiting sugar digestive enzymes and DPP-IV. Prenylated stilbenoids present remarkable DPP-IV inhibitory activity, providing more useful information for the prevention of type 2 diabetes.