Orlistat

Orlistat is a drug that promotes loss of weight by preventing the digestion and absorption of fat in food. It is intended for use in conjunction with a physician-supervised reduced-calorie diet. Orlistat is the saturated derivative of lipstatin, a potent natural inhibitor of pancreatic lipases isolated from the bacterium Streptomyces toxytricini. However, due to simplicity and stability, orlistat rather than lipstatin was developed into an anti-obesity drug. In vitro experiments demonstrate that orlistat has an IC50 of 122 ng/ml for PL from human duodenal juice, but an IC50 of about 300 ng/ml for LPL.