Inhibition of phosphatidylinositol-3-kinase by the furanosesquiterpenoid hibiscone C.

The phosphatidylinositol-3-kinase (PIK) pathway regulates cellular metabolism and is upregulated in many cancers, making it an attractive chemotherapeutic target. Wortmannin is a potent inhibitor of PIK; however, its potential as a chemotherapeutic is limited due to its instability, lack of selectivity, and lengthy chemical synthesis. In contrast, hibiscone C, a structurally simpler and less studied member of the furanosteroid family, has been expediently prepared by total synthesis. We demonstrate that hibiscone C competitively inhibits PIK activity in intact cells, slows proliferation, and induces cell death. Hibiscone C may therefore serve as a productive scaffold for the development of therapeutically relevant PIK inhibitors.