O-(triazolyl)methyl carbamates as a novel and potent class of fatty acid amide hydrolase (FAAH) inhibitors

Synthesis and evaluation of carbamate derivatives as fatty acid amide hydrolase and monoacylglycerol lipase inhibitors

Fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) are the primary catabolic enzymes for endocannabinoids, anandamide (AEA), and 2-arachidonoyl glycerol. Numerous studies have shown that FAAH and MAGL play an important role in modulating various central nervous system activities; hence, the development of small molecule FAAH/MAGL inhibitors is an active area of research. Several small molecules possessing the carbamate scaffold are documented as potential FAAH/MAGL inhibitors. Here, we designed and synthesized a series of open chain and cyclic carbamates and evaluated their dual FAAH-MAGL inhibition properties. Phenyl [4-(piperidin-1-ylmethyl)phenyl]carbamate (2e) emerged as the most potent MAGL inhibitor (IC₅₀  = 19 nM), benzyl (1H-benzo[d]imidazol-2-yl)carbamate (3h) was the most potent FAAH inhibitor (IC₅₀  = 55 nM), and phenyl (6-fluorobenzo[d]thiazol-2-yl)carbamate (2i) egressed as a nonselective dual FAAH-MAGL inhibitor (FAAH: 82 nM, MAGL: 72 nM). The enzyme kinetics experiments revealed that the compounds inhibit FAAH/MAGL in a covalent-reversible manner, with a mixed binding mode of action. Moreover, the lead compounds were found suitable for blood-brain permeation in the parallel artificial membrane permeation assay. Furthermore, docking simulation experiments suggested that the potency of the lead compounds was governed by hydrogen bonds and hydrophobic interactions with the enzyme active sites. In silico drug-likeness and ADMETox prediction studies provided useful information on the compounds' oral absorption, metabolism, and toxicity profiles. In summary, this study afforded potent multifunctional carbamates with appreciable pharmacokinetic profiles meriting further investigation.

Synthesis and In Vitro Cytotoxicity and Antibacterial Activity of Novel 1,2,3-Triazol-5-yl-phosphonates

Novel 1,2,3-triazol-5-yl-phosphonates were prepared by the copper(I)-catalyzed domino reaction of phenylacetylene, organic azides and dialkyl phosphites. The process was optimized on the synthesis of the dibutyl (1-benzyl-4-phenyl-1H-1,2,3-triazol-5-yl)phosphonate in respect of the catalyst, the base and the solvent, as well as of the reaction parameters (molar ratio of the starting materials, atmosphere, temperature and reaction time). The method elaborated could be applied to a range of organic azides and dialkyl phosphites, which confirmed the large scope and the functional group tolerance. The in vitro cytotoxicity on different cell lines and the antibacterial activity of the synthesized 1,2,3-triazol-5-yl-phosphonates was explored. According to the IC50 values determined, only modest antibacterial effect was detected, while some derivatives showed moderate activity against human promyelocytic leukemia HL-60 cells.

Synthesis of (1,2,3-triazol-4-yl)methyl Phosphinates and (1,2,3-Triazol-4-yl)methyl Phosphates by Copper-Catalyzed Azide-Alkyne Cycloaddition

An efficient and practical method was developed for the synthesis of new (1,2,3triazol4yl)methyl phosphinates and (1,2,3-triazol-4-yl)methyl phosphates by the copper(I)catalyzed azide-alkyne cycloaddition (CuAAC) of organic azides and prop-2-ynyl phosphinate or prop-2-ynyl phosphate. The synthesis of (1benzyl-1H-1,2,3-triazol-4-yl)methyl diphenylphosphinate was optimized with respect to the reaction parameters, such as the temperature, reaction time, and catalyst loading. The approach was applied to a range of organic azides, which confirmed the wide scope and the substituent tolerance of the process. The method elaborated represents a novel approach for the synthesis of the target compounds.

Facile and highly diastereo and regioselective synthesis of novel octahydroacridine-isoxazole and octahydroacridine-1,2,3-triazole molecular hybrids from citronella essential oil

A novel and highly efficient synthetic approach for the expedite construction of new octahydroacridine-isoxazole- and octahydroacridine-1,2,3-triazole-based molecular hybrids is first reported. Rapid access to the octahydroacridine core was achieved in a highly diastereoselective fashion via cationic Povarov reaction of N-propargyl anilines and citronella essential oil (Cymbopogon nardus). The subsequent 1,3-dipolar and Cu (I) catalyzed alkyne-azide cycloaddition reaction of the terminal alkyne fragment with the corresponding oxime or azide affords the desired 3,5-isoxazoles and 1,2,3-triazoles, respectively, as interesting molecular hybrid models for pharmacological studies.

A Swath Label-Free Proteomics insight into the Faah-/- Mouse Liver

Fatty acid amide hydrolase (FAAH) is an important enzyme for lipid metabolism and an interesting pharmacological target, given its role in anandamide breakdown. The FAAH^−/− genotype is the most widely used mouse model to investigate the effects of a complete pharmacological inhibition of this enzyme. In this paper, we explore, by means of label-free SWATH proteomics, the changes in protein expression occurring in the liver of FAAH^−/− knockout (KO) mice. We identified several altered biological processes and pathways, like fatty acid synthesis and glycolysis, which explain the observed phenotype of this mouse. We also observed the alteration of other proteins, like carboxylesterases and S-methyltransferases, apparently not immediately related to FAAH, but known to have important biological roles. Our study, reporting more than 3000 quantified proteins, offers an in-depth analysis of the liver proteome of this model.

Research progress of mechanisms and drug therapy for neuropathic pain

Neuropathic pain is maladaptive pain caused by injury or dysfunction in peripheral and central nervous system, and remains a worldwide thorny problem leading to decreases in physical and mental quality of people's life. Currently, drug therapy is the main treatment regimen for resolving pain, while effective drugs are still unmet in medical need, and commonly used drugs such as anticonvulsants and antidepressants often make patients experience adverse drug reactions like dizziness, somnolence, severe headache, and high blood pressure. Thus, in this review we overview the anatomical physiology, underlying mechanisms of neuropathic pain to provide a better understanding in the initiation, development, maintenance, and modulation of this pervasive disease, and inspire research in the unclear mechanisms as well as potential targets. Furthermore, we summarized the existing drug therapies and new compounds that have shown antalgic effects in laboratory studies to be helpful for rational regimens in clinical treatment and promotion in novel drug discovery.

Structure-activity relationship studies of QS11, a small molecule Wnt synergistic agonist

Both the Wnt/β-catenin signaling pathway and small GTPases of the ADP-ribosylation factors (ARF) family play important roles in regulating cell development, homeostasis and fate. The previous report of QS11, a small molecule Wnt synergist that binds to ARF GTPase-activating protein 1 (ARFGAP1), suggests a role for ARFGAP1 in the Wnt/β-catenin pathway. However, direct inhibition of enzymatic activity of ARFGAP1 by QS11 has not been established. Whether ARFGAP1 is the only target that contributes to QS11's Wnt synergy is also not clear. Here we present structure-activity relationship (SAR) studies of QS11 analogs in two assays: direct inhibition of enzymatic activity of purified ARFGAP1 protein and cellular activation of the Wnt/β-catenin pathway. The results confirm the direct inhibition of ARFGAP1 by QS11, and also suggest the presence of other potential cellular targets of QS11.