Chaetochromin, also known as 4548-G05, is an orally active, small-molecule, selective agonist of the insulin receptor.[1] It has potent and long-lasting antidiabetic activity in vivo in mice. The drug may represent a novel potential therapeutic agent for the treatment of diabetes which is more convenient and tolerable to administer than injected insulin. It was discovered in 1981 in Chaetomium gracile fungi,[2] and its interaction with the insulin receptor was identified in 2014.
Chaetochromin A and B are stereoisomers of this structure, while chaetochromin C and D are related but different compounds.[3] It is not known whether the insulin mimetic effect was found in chaetochromin A or B, or in a mixture.