1. J Med Chem. 2009 Dec 10;52(23):7410-20. Synthesis and in vitro evaluation of N-substituted maleimide derivatives as selective monoglyceride lipase inhibitors. Matuszak N, Muccioli GG, Labar G, Lambert DM. Faculté de Medecine, Unité de Chimie Pharmaceutique et de Radiopharmacie, Louvain Drug Research Institute, Ecole de Pharmacie, Drug Design and Discovery Centre, Université Catholique de Louvain, B-1200 Bruxelles, Belgium. The endocannabinoid 2-arachidonoylglycerol (2-AG) plays a major role in many physiological processes, and its action is quickly terminated via enzymatic hydrolysis catalyzed by monoglyceride lipase (MGL). Regulating its endogenous level could offer therapeutic opportunities; however, few selective MGL inhibitors have been described so far. Here, we describe the synthesis of N-substituted maleimides and their pharmacological evaluation on the recombinant human fatty acid amide hydrolase (FAAH) and on the purified human MGL. A few N-arylmaleimides were previously described ( Saario , S. M. ; Salo , O. M. ; Nevalainen , T. ; Poso , A. ; Laitinen , J. T. ; Jarvinen , T. ; Niemi , R. Characterization of the Sulfhydryl-Sensitive Site in the Enzyme Responsible for Hydrolysis of 2-Arachidonoylglycerol in Rat Cerebellar Membranes . Chem. Biol. 2005 , 12 , 649 - 656 ) as MGL inhibitors, and along these lines, we present a new set of maleimide derivatives that showed low micromolar IC(50) and high selectivity toward MGL vs FAAH. Then, structure-activity relationships have been investigated and, for instance, 1-biphenyl-4-ylmethylmaleimide inhibits MGL with an IC(50) value of 790 nM. Furthermore, rapid dilution experiments reveal that these compounds act as irreversible inhibitors. In conclusion, N-substituted maleimides constitute a promising class of potent and selective MGL inhibitors. PMID: 19583260 [PubMed - indexed for MEDLINE]