Fusidienol: A novel inhibitor of Ras farnesyl-protein transferase from Fusidium griseum

Ras (p21) protein is frequently found mutated in human cancers and must be farnesylated by farnesyl protein-transferase (FPTase) to achieve cell-transforming activity. Our continued search for inhibitors of FPTase as potential cancer chemotherapeutics led to the isolation of fusidienol from extracts of the fungus Fusidium griseum. Fusidienol is a novel and potent oxygen-containing [7/6/6] tricyclic heterocycle.