Synthesis of Benzylidene Analogs of Oleanolic Acid as Potential α-Glucosidase and α-Amylase Inhibitors

A series of benzylidene analogs of oleanolic acid 4a∼4s were synthesized and assessed for their α -glucosidase and α -amylase inhibitory activities. The results presented that all synthesized analogs exhibited excellent-to-moderate inhibitory effects on α -glucosidase and α -amylase. Analog 4i showed the highest α -glucosidase inhibition (IC 50 : 0.40 μM), and analog 4o presented the strongest α -amylase inhibition (IC 50 : 9.59 μM). Inhibition kinetics results showed that analogs 4i and 4o were reversible and mixed-type inhibitors against α -glucosidase and α -amylase, respectively. Simulation docking results demonstrated the interaction between analogs and two enzymes. Moreover, analogs 4i and 4o showed a high level of safety against 3T3-L1 and HepG2 cells.