UPLC/MS analysis: Rt 2 . 43 min. to the identification of achiral (18b) as well as racemic (29a-cand29e) analogs. Absolute configurational assignment and pharmacological evaluation of single enantiomers of10rare also presented. (S)-(+)-10ris the first highly potent and selective chiral inhibitor of FAAH-COX with markedin vivoactivity, and represents a promising lead to discover novel analgesics and anti-inflammatory drugs. Keywords: FAAH, COX, hybrid scaffold, multitarget inhibitors, structure-activity relationship, inflammation == Graphical Fuzy == == 1 . Launch == Non-steroidal anti-inflammatory drugs (NSAIDs) are widely utilized to treat pain and inflammation, [1] but their chronic use is hindered by a variety of potentially serious negative events that include gastrointestinal (GI) mucosal lesions, bleeding and perforations. [2-5] Conventional NSAIDs inhibit both isoforms of cyclooxygenase (COX), COX-1 and COX-2, which catalyze the first committed steps in the biosynthetic pathway that converts arachidonic acidity (AA) into inflammatory prostanoids such as prostaglandin E2(PGE2) and thromboxane A2(TXA2). [6] The dual role of COX-1-derived PGE2as inflammation promoter and mucosal cells protectant explains, at least in part, why NSAIDs cause damage to the GI tract. [7-10] Efforts to overcome this issue have led to the development of selective COX-2 inhibitors, which combine a high level of anti-inflammatory efficacy ADRBK1 with a reduced propensity to cause injury to the GI mucosa. [6] Nevertheless, the use of COX-2 inhibitors has been linked to a distinctive set of adverse cardiovascular effects. [11, 12] Thus, the need for safe and effective drugs that can be used in the treatment of chronic inflammatory disorders remains urgent. A promising approach to fulfill this need is offered by focusing on with a single agent more than one component of the inflammatory cascade. [13-15] Providers designed to achieve this objective include nitric oxide (NO) donors-NSAIDs, J147 [16, 17] COX-2 inhibitors-NO-donors, [18, 19] hydrogen sulfide (H2S) donors-NSAIDs, [20-22] as well as compounds that block unique enzymes from the AA pathway, such as COX/lipoxygenase [23, 24] and COX-2/soluble epoxy hydrolase (sEH). [25] Another potential multi-target strategy to treat inflammation is the concomitant inhibition of COX and fatty acid amide hydrolase (FAAH) [26], [27-33] a serine hydrolase that deactivates a family of analgesic and anti-inflammatory lipid amides that are produced by host-defense cells and other cells in the body. [34, 35] These lipid mediators include the endocannabinoid anandamide (arachidonoylethanolamide) which engages cannabinoid-1 (CB1) and CB2receptors to suppress neutrophil migration [36] and prevent immune-cell recruitment [37, 38] as well as the endogenous peroxisome proliferator-activate receptor- (PPAR-) agonists, palmitoylethanolamide (PEA) and oleoylethanolamide (OEA). [39-41] In addition to opposing pain and inflammation, these FAAH substrates are protective from the GI mucosa. [42, 43] Indeed, studies in creature pain versions have shown that co-administration of FAAH and COX inhibitors results in a synergistic potentiation of analgesia along with reduced gastric damage. [44-46] In several chronic inflammatory conditions, including inflammatory bowel disease (IBD), FAAH [47-49] and COX-2 [50] are expressed at abnormally high levels. This J147 simultaneous up-regulation may help establish a pathological state that exacerbates inflammation by amplifying inflammatory COX-dependent signals at the expense of defensive FAAH-regulated mediators. This hypothesis predicts that drugs focusing on both COX and FAAH should have substantial anti-inflammatory efficacy combined with reduced GI toxicity. In a recent study, we provided support to this hypothesis using a multi-target modulator based on the hybrid scaffold1(Figure 1). [51] This scaffold merges key pharmacophores of two known classes of FAAH and COX inhibitors O-aryl carbamates [52-58] such as [3-(3-carbamoylphenyl)phenyl]N-cyclohexylcarbamate (URB597, 2) [54, 57], and 2-aryl propionic acids [6] such as flurbiprofen, 3a[59-61] which share a biphenyl primary as a common J147 structural motif (AandBrings, Physique 1). Moreover, structure-activity relationship (SAR) studies of these scaffolds supported the hypothesis of additional elements of structural overlapping, such as the oxygenated substituents at the3-position of theAphenyl ring, corresponding to the carbamate functionality of2[53, 54, 56] and the ether moieties of3bor3c, [61] respectively (Figure 1). == Physique 1 . == Rational design of a hybrid scaffold to get FAAH and COX inhibition. This SAR work led to the identification of compound10r(()-2-[3-fluoro-4-[3-(hexylcarbamoyloxy)phenyl]phenyl]propanoic acid, ARN2508) [51] as a potentin vivoactive inhibitor of intracellular FAAH and COX activities, which exerts serious anti-inflammatory effects in mouse models of IBD without leading to COX-dependent gastric toxicity. [51] In the present research, (a) we outline the in-depth SAR investigations that led to the discovery of compound10r[51]; (b) we report an expansion of this SAR work, which culminated in the identification of a number of new and potent multitarget inhibitors (18b, 29a-cand29e); and, finally (c) we explain the absolute configurational assignment and pharmacological properties of.