title: SAR and LC/MS studies of β-lactamic inhibitors of human fatty acid amide hydrolase (hFAAH): evidence of a nonhydrolytic process.
abstract: The endocannabinoid hydrolyzing enzyme FAAH uses a nonclassical catalytic triad (namely, Ser-Ser-Lys instead of Ser-Asp-His) to cleave its endogenous substrates. Because inhibiting FAAH has a clear therapeutic potential, we previously developed β-lactam-type inhibitors of hFAAH. Here, we report the synthesis of five novel derivatives (5-9) of our lead compound 1-(pent-4-enoyl)-3(S)-[1(R)-(4-phenylbutanoyloxy)-ethyl]-azetidin-2-one (4, IC(50) = 5 nM) obtained via the systematic replacement of one to three carbonyls by methylene groups. The SAR results showed that the imide, but not the lactam, function is essential to the inhibition of hFAAH. We also performed LC/MS analysis following incubation of our inhibitors with hFAAH or mouse liver. We demonstrated that hFAAH interacts with these β-lactam-type inhibitors but, unexpectedly, does not open the β-lactam moiety. This mechanism seems to be unique to FAAH because the β-lactam function of the inhibitors is hydrolyzed when they are incubated in the presence of the serine hydrolases expressed in the mouse liver. Finally, we confirmed these results by showing that a highly selective FAAH inhibitor (PF-750) does not prevent this hydrolysis by liver homogenates.
authors: Laboratoire de Chimie Organique et Médicinale, Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Bâtiment Lavoisier, Place Louis Pasteur L4.01.02, B-1348 Louvain-La-Neuve, Belgium.
authors: Marion
authors: M
authors: Feledziak
authors: Giulio G
authors: GG
authors: Muccioli
authors: Didier M
authors: DM
authors: Lambert
authors: Jacqueline
authors: J
authors: Marchand-Brynaert
mesh_terms: D000581:Amidohydrolases / Q000037:antagonists & inhibitors*; D000818:Animals; D001384:Azetidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006868:Hydrolysis; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism; D013058:Mass Spectrometry; D051379:Mice; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D047090:beta-Lactams / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D000099252:Fatty Acid Amide Hydrolases
chemical_list: D000581:Amidohydrolases; D001384:Azetidines; D011994:Recombinant Proteins; D047090:beta-Lactams; D000099252:Fatty Acid Amide Hydrolases