Design and synthesis of further simplified pyripyropene A based ACAT2 selective inhibitors

Acyl-coenzyme A: cholesterol acyltransferases (ACATs) play the significant role in the formation of cholesterol esters. One form of this enzyme is ACAT2, which not only regulates the balance of cholesterol metabolism in cells but also participates in the “escape” mechanism of hepatocellular carcinoma (HCC) cells. The natural product pyripyropene A (PPPA) and its analogs are the only chemical ACAT2-specific inhibitors. To develop simpler analogs and endeavor to remove a portion of multichiral centers and enrich a variety of analogs, new PPPA analogs are creatively designed and synthesized based on previous work. Among these new analogs, 7a and 9f show better activity and selective inhibition of ACAT2 compared with PPPA. These results will provide a new future for potential therapeutic use in atherosclerosis and HCC.