Chiral 3-(4,5-dihydrooxazol-2-yl)phenyl alkylcarbamates as novel FAAH inhibitors: Insight into FAAH enantioselectivity by molecular docking and interaction fields

Fatty acid amide hydrolase (FAAH) and monoglyceride lipase (MGL) are the main enzymes responsible for the hydrolysis of endogenous cannabinoids N-arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG), respectively. Phenyl alkylcarbamates are FAAH inhibitors with anxiolytic and analgesic activities in vivo. Herein we present for the first time the synthesis and biological evaluation of a series of chiral 3-(2-oxazoline)-phenyl N-alkylcarbamates as FAAH inhibitors. Furthermore, the structural background of chirality on the FAAH inhibition is explored by analyzing the protein–ligand interactions. Remarkably, 10-fold difference in potency was observed for (R)- and (S)-derivatives of 3-(5-methyl-4,5-dihydrooxazol-2-yl)phenyl cyclohexylcarbamate (6a vs. 6b). Molecular modelling indicated an important interaction between the oxazoline nitrogen and FAAH active site.