Compactin is a cholesterol biosynthesis inhibitor produced by Penicillum brevicompactum. It has weak antifungal activity and can inhibit the key enzyme in cholesterol biosynthesis pathway -3- transyl-3-methylglutaryl-coa reductase, showing good cholesterol lowering effect in animals and humans. It was the pioneer in the discovery of statins lipid-lowering drugs and is now used as a biochemical reagent.