2-(4-Fluorophenyl)-5-(2-naphthyl)-1,3,4-oxadiazole

2-(4-Fluorophenyl)-5-(2-naphthyl)-1,3,4-oxadiazole is a clinical drug that is used to diagnose the presence of cholesterol in human serum. It reacts with cholesterol esterase to form a fluorescent product. The fluorescence intensity of this reaction product can then be measured and used to determine the concentration of cholesterol in the sample. 2-(4-Fluorophenyl)-5-(2-naphthyl)-1,3,4-oxadiazole has been shown to have a high specificity for cholesterol esterase and does not react with enzymes such as carboxylesterases and cholesteryl esterases. This compound also inhibits uptake into cells by acting on an uptake carrier protein, which prevents it from entering cells.