Oleanolic acid

► Oleanolic acid is a triterpenoid compound present in many plant species. ► The complete biosynthetic pathway leading to oleanolic acid is elucidated. ► Oleanolic acid exerts pharmacological activities such as hepatoprotective effects. ► Chemical derivatives of oleanolic acid have increased pharmacological activities. ► Perspectives on heterologous biosynthesis of oleanolic acid and its derivatives.