2-Hydroxy atorvastatin lactone

2-Hydroxy atorvastatin lactone is an active metabolite of the drug atorvastatin. This small molecule is a potent, orally bioavailable inhibitor of HMG-CoA reductase, the rate-limiting enzyme in cholesterol biosynthesis. It is widely used in biochemical and pharmacological research to study lipid metabolism and the mechanisms of statins in both in vitro and in vivo models.