Stelt, M. van der, Boeckel, C.A.A. van, Berg, R.J.B.H.N. van den, Overkleeft, H.S., Heitman, L.H., Westen, G.J.P. van, Baggelaar, M.P., Witkamp, R.F., Martin N.I., Leiden University
Monoacylglycerol lipase (MAGL) is the principal enzyme responsible for hydrolysis of the endocannabinoid 2-arachidonoylglycerol (2-AG). MAGL inhibition provides several potential therapeutic opportunities, including anti-nociceptive, anti-inflammatory and anti-cancer activity. This thesis describes the discovery of LEI-515 as peripherally restricted, reversible MAGL inhibitor. A library of 233.820 compounds was screened at the Pivot Park Screening Center and 7 hits were confirmed. Over 100 analogues of the most promising hit were designed, synthesized and evaluated in a natural substrate assay and activity-based protein profiling. This resulted in the identification of LEI-515, which has subnanomolar inhibitory potency, high selectivity and good metabolic stability. LEI-515 is a reversible inhibitor that forms a hemiketal with catalytic Ser122, stabilized by hydrogen bonds with Ala53 and Met123. LEI-515 is > 100-fold selective over a panel of 44 ion channels, receptors and enzymes, including the cannabinoid CB1 and CB2 receptor, hERG and cyclooxygenases. Targeted lipidomics revealed that LEI-515 increased cellular 2-AG levels in a concentration and time-dependent manner. Pharmacokinetic studies indicated that LEI-515 has excellent oral bioavailability, but does not penetrate the brain.