U-18666A (3039-71-2) is an oxidosqualene reductase inhibitor.1 Inhibits the egress of cholesterol from late endosomes and lysosomes.2 U-18666A is also used to study Niemann-Pick disease and for assessing the importance of molecular trafficking through the lysosomal pathway in other conditions.3
U 18666A is a cell-permeable amphiphilic amino-steroid.
ChEBI: 3beta-(2-diethylaminoethoxy)androst-5-en-17-one hydrochloride is a hydrochloride obtained by reaction of 3beta-(2-diethylaminoethoxy)androst-5-en-17-one with one equivalent of hydrochloric acid. It is a cholesterol synthesis and transport inhibitor. It has a role as an EC 1.3.1.72 (Delta(24)-sterol reductase) inhibitor, a nicotinic antagonist, a sterol biosynthesis inhibitor, an antiviral agent and a Hedgehog signaling pathway inhibitor. It contains a 3beta-(2-diethylaminoethoxy)androst-5-en-17-one(1+).
A cell-permeable, amphiphilic amino-steroid that alters intracelluar membrane protein trafficking by impairing intracellular biosynthesis and transport of LDL-derived cholesterol. Reported to exert its effects via the inhibition of 2,3-oxidosqualene-lanosterol cyclase activity. Also reported to inhibit the activity of Δ8-sterol isomerase.
Inhibitor of cholesterol synthesis and cellular transport, and weak inhibitor of hedgehog (Hh) signaling. Reduces serum sterol levels in rats in vivo .
U-18666A is a cell permeable drug that inhibits cholesterol transport. This small molecule inhibits low density lipoprotein-derived cholesterol transport, blocking cholesterol esterification, and suppressing LDL receptor activities. Studies have shown that impaired cholesterol trafficking is associated with neurological diseases such as Alzheimer’s disease, Niemann-Pick disease type C, and atherosclerosis. The mechanisms of neurodegeneration for these diseases are mostly unknown so studies using U-18666A to simulate intracellular cholesterol accumulation may provide greater insight into these pathologies. Cholesterol levels play a role in the body’s response to viral infection and the ability of a virus to enter and replicate within a host cell, making U-18666A an important compound when studying different viral diseases.
[1] RUSSELL C. SEXTON. Effects of 3.beta.-[2-(diethylamino)ethoxy]androst-5-en-17-one on the synthesis of cholesterol and ubiquinone in rat intestinal epithelial cell cultures[J]. Biochemistry Biochemistry, 1983, 22 25: 5687-5692. DOI:
10.1021/bi00294a001[2] L LISCUM J R F. The intracellular transport of low density lipoprotein-derived cholesterol is inhibited in Chinese hamster ovary cells cultured with 3-beta-[2-(diethylamino)ethoxy]androst-5-en-17-one.[J]. The Journal of Biological Chemistry, 1989, 264 20: 11796-11806.
[3] CENEDELLA R J. Cholesterol Synthesis Inhibitor U18666A and the Role of Sterol Metabolism and Trafficking in Numerous Pathophysiological Processes[J]. Lipids, 2009, 44 6: 477-487. DOI:
10.1007/s11745-009-3305-7
