Pentacyclic triterpenes. Part 2: Synthesis and biological evaluation of maslinic acid derivatives as glycogen phosphorylase inhibitors

The synthesis of a series of maslinic acid derivatives is described and their effect on rabbit muscle glycogen phosphorylase a evaluated. Within this series of compounds, 15 (IC50 = 7 μM) is the most potent GPa inhibitor. SAR of the maslinic acid derivatives are discussed.