Chemical, Biochemical, Cellular, and Physiological Characterization of Leucettinib-21, a Down Syndrome and Alzheimer's Disease Drug Candidate.

Leucettinibs are substituted 2-aminoimidazolin-4-ones (inspired by the marine sponge natural product Leucettamine B) developed as pharmacological inhibitors of DYRK1A (dual-specificity, tyrosine phosphorylation-regulated kinase 1A), a therapeutic target for indications such as Down syndrome and Alzheimer's disease. Leucettinib-21 was selected as a drug candidate following extensive structure/activity studies and multiparametric evaluations. We here report its physicochemical properties (X-ray powder diffraction, differential scanning calorimetry, stability, solubility, crystal structure) and drug-like profile.

Leucettinibs, a Class of DYRK/CLK Kinase Inhibitors Inspired by the Marine Sponge Natural Product Leucettamine B.

Dual-specificity, tyrosine phosphorylation-regulated kinases (DYRKs) and cdc2-like kinases (CLKs) recently attracted attention due to their central involvement in various pathologies. We here describe a family of DYRK/CLK inhibitors derived from Leucettines and the marine natural product Leucettamine B. Forty-five 2-functionalized 2-aminoimidazolin-4-ones bearing a fused [6 + 5]-heteroarylmethylene were synthesized.

Comparative Efficacy and Selectivity of Pharmacological Inhibitors of DYRK and CLK Protein Kinases.

Dual-specificity, tyrosine phosphorylation-regulated kinases (DYRKs) and cdc2-like kinases (CLKs) play a large variety of cellular functions and are involved in several diseases (cognitive disorders, diabetes, cancers, etc.). There is, thus, growing interest in pharmacological inhibitors as chemical probes and potential drug candidates.

Discovery and Optimization of Potent and Orally Available CTP Synthetase Inhibitors for Use in Treatment of Diseases Driven by Aberrant Immune Cell Proliferation.

Herein, we report the discovery of a first-in-class chemotype 2-(alkylsulfonamido)thiazol-4-yl)acetamides that act as pan-selective inhibitors of cytidine 5'-triphosphate synthetase (CTPS1/2), critical enzymes in the pyrimidine synthesis pathway. Weak inhibitors identified from a high-throughput screening of 240K compounds have been optimized to a potent, orally active agent, compound , which has shown significant pharmacological responses at 10 mg/kg dose BID in a well-established animal model of inflammation.

Design and synthesis of a novel series of histamine H3 receptor antagonists through a scaffold hopping strategy.

Lead compounds 5-fluoro-2-methyl-N-[2-methyl-4-(2-methyl-[1,3']bipyrrolidinyl-1'-yl)-phenyl]-benzamide (1), tetrahydro-pyran-4-carboxylic acid [((2S,3'S)-2-methyl-[1,3']bipyrrolidinyl-1'-yl)-phenyl]-amide (2), and 3,5-dimethyl-isoxazole-4-carboxylic acid [((2S,3'S)-2-methyl-[1,3']bipyrrolidinyl-1'-yl)-phenyl]-amide (3) discovered in our laboratory, displayed high histamine H3 receptor (H3R) affinity, good selectivity and weak human Ether-à-go-go-Related Gene (hERG) channel affinity with desirable overall physico-chemical and pharmacokinetic (PK) profiles. Herein, we describe the design and synthesis of a novel series of H3R antagonists utilizing a scaffold hopping strategy. Further structure-activity relationship (SAR) studies of the series culminated in the identification of ((2S,3'S)-2-methyl-[1,3']bipyrrolidinyl-1'-yl)-naphthalene-2-carboxylic acid (tetrahydro-pyran-4-yl)-amide (4c) and -[4-((2S,3'S)-2-methyl-[1,3']bipyrrolidinyl-1'-yl)-phenyl]-N-(tetrahydro-pyran-4-yl)-acetamide (4d), which exhibited good H3R affinity in vitro, good selectivity, and desirable PK properties.

Selective blockade of the hydrolysis of the endocannabinoid 2-arachidonoylglycerol impairs learning and memory performance while producing antinociceptive activity in rodents.

Monoacylglycerol lipase (MAGL) represents a primary degradation enzyme of the endogenous cannabinoid (eCB), 2-arachidonoyglycerol (2-AG). This study reports a potent covalent MAGL inhibitor, SAR127303. The compound behaves as a selective and competitive inhibitor of mouse and human MAGL, which potently elevates hippocampal levels of 2-AG in mice.

Identification and profiling of 3,5-dimethyl-isoxazole-4-carboxylic acid [2-methyl-4-((2S,3'S)-2-methyl-[1,3']bipyrrolidinyl-1'-yl)phenyl] amide as histamine H(3) receptor antagonist for the treatment of depression.

Lead optimization guided by histamine H3 receptor (H3R) affinity and calculated physico-chemical properties enabled simultaneous improvement in potency and PK properties leading to the identification of a potent, selective, devoid of hERG issues, orally bioavailable, and CNS penetrable H3R antagonist/inverse agonist 3h. The compound was active in forced-swimming tests suggesting its potential therapeutic utility as an anti-depressive agent. This Letter further includes its cardiovascular and neuropsychological/behavioral safety assessments.

Discovery of a potent, selective, and orally bioavailable histamine H3 receptor antagonist SAR110068 for the treatment of sleep-wake disorders.

Previous studies have shown that compound 1 displayed high affinity towards histamine H3 receptor (H3R), (human (h-H3R), K(i)=8.6 nM, rhesus monkey (rh-H3R), K(i)=1.2 nM, and rat (r-H3R), K(i)=16.

Synthesis, characterization, and biological assessment of the four stereoisomers of the H(3) receptor antagonist 5-fluoro-2-methyl-N-[2-methyl-4-(2-methyl[1,3']bipyrrolidinyl-1'-yl)phenyl]benzamide.

This Letter describes the asymmetric synthesis of the four stereoisomers (8a-8d) of a potent and highly selective histamine H3 receptor (H3R) antagonist, 5-fluoro-2-methyl-N-[2-methyl-4-(2-methyl[1,3']bipyrrolidinyl-1'-yl) phenyl]benzamide (1). The physico-chemical properties, in vitro H3R affinities and ADME of 8a-8d were determined. Stereoisomer 8c (2S,3'S) displayed superior in vitro H3R affinity over other three stereoisomers and was selected for further profiling in in vivo PK and drug safety.

Discovery of aryl ureas and aryl amides as potent and selective histamine H3 receptor antagonists for the treatment of obesity (part II).

A novel series of histamine H3 receptor (H3R) antagonists was derived from an arylurea lead series (1) via bioisosteric replacement of the urea functionality by an amide linkage. The arylamide series was optimized through SAR studies by a broad variation of substituents in the left-hand side benzoyl residue (analogs 2a-2ag) or replacement of the benzoyl moiety by heteroarylcarbonyl residues (analogs 5a-5n). Compounds 2p and 2q were identified within the series as potent and selective H3R antagonists/inverse agonists with acceptable overall profile.

Discovery of aryl ureas and aryl amides as potent and selective histamine H3 receptor antagonists for the treatment of obesity (part I).

A series of structurally novel aryl ureas was derived from optimization of the HTS lead as selective histamine H3 receptor (H3R) antagonists. The SAR was explored and the data obtained set up the starting point and foundation for further optimization. The most potent tool compounds, as exemplified by compounds 2l, 5b, 5d, and 5e, displayed antagonism potencies in the subnanomolar range in in vitro human-H3R FLIPR assays and rhesus monkey H3R binding assays.

Ring expansion of cyclic β-amino alcohols induced by diethylaminosulfur trifluoride: synthesis of cyclic amines with a tertiary fluorine at C3.

As the replacement of a hydrogen atom by a fluorine atom in a compound can have an important impact on its biological properties, the development of methods allowing the introduction of a fluorine atom is of great importance. The scope and limitations of the ring expansion of cyclic 2-hydroxymethyl amines induced by diethylaminosulfur trifluoride (DAST) to produce cyclic β-fluoro amines was studied as well as the enantioselectivity of the process.

Synthesis of aminopyridines and aminopyridones by cobalt-catalyzed [2+2+2] cycloadditions involving yne-ynamides: scope, limitations, and mechanistic insights.

An in-depth study of the cobalt-catalyzed [2+2+2] cycloaddition between yne-ynamides and nitriles to afford aminopyridines has been carried out. About 30 nitriles exhibiting a broad range of steric demand and electronic properties have been evaluated, some of which open new perspectives in metal-catalyzed arene formation. In particular, the use of [CpCo(CO)(dmfu)] (dmfu=dimethyl fumarate) as a precatalyst made possible the incorporation of electron-deficient nitriles into the pyridine core.

Synthesis and biological evaluation of analogues of M6G.

Synthesis and biological evaluation of new derivatives of Morphine-6-Glucuronide (M6G) are described. M6G is an active metabolite of morphine which displays more analgesia than morphine with a superior side effect profile but with a less efficiently BBB penetration. These phenomena could be explained by the presence of the glucuronide moiety, which confers a higher hydrophilic character compare to morphine.

Regioselective cobalt-catalyzed formation of bicyclic 3- and 4-aminopyridines.

Bimolecular cobalt-catalyzed [2 + 2 + 2] cycloadditions between yne-ynamides and nitriles afford bicyclic 3- or 4-aminopyridines in up to 100% yield. The high regioselectivity observed depends on the substitution pattern at the starting ynamide. Aminopyridines bearing TMS and Ts groups are efficiently deprotected in an orthogonal fashion.

In vivo quantification of monoamine oxidase A in baboon brain: a PET study using [(11)C]befloxatone and the multi-injection approach.

[(11)C]befloxatone is a high-affinity, reversible, and selective radioligand for the in vivo visualization of the monoamine oxidase A (MAO-A) binding sites using positron emission tomography (PET). The multi-injection approach was used to study in baboons the interactions between the MAO-A binding sites and [(11)C]befloxatone. The model included four compartments and seven parameters.

[(11)C]SL25.1188, a new reversible radioligand to study the monoamine oxidase type B with PET: preclinical characterisation in nonhuman primate.

[(11)C]SL-25.1188 [(S)-5-methoxymethyl-3-[6-(4,4,4-trifluorobutoxy)-benzo[d]isoxazol-3-yl]-oxazolidin-2-one], an oxazolidinone derivative, was characterized in baboons as a radioligand for the in vivo visualization of MAO-B using positron emission tomography (PET). After i.

Characterization of SSR103800, a selective inhibitor of the glycine transporter-1 in models predictive of therapeutic activity in schizophrenia.

On native human, rat and mouse glycine transporter-1(GlyT1), SSR130800 behaves as a selective inhibitor with IC50 values of 1.9, 5.3 and 6.

Synthesis of new potentially bioactive bicyclic 2-pyridones.

Three convenient methods of reduction of the nitro group of 5-nitroimidazoles and 5-nitrothiazole that bear a diethylmethylene malonate group in an ortho-like position with respect to the nitro group and cyclization of the resulting amino derivatives are reported. These reactions afforded the target bicyclic 2-pyridones in good to excellent yields.

SSR180711, a novel selective alpha7 nicotinic receptor partial agonist: (1) binding and functional profile.

In this paper, we report on the pharmacological and functional profile of SSR180711 (1,4-Diazabicyclo[3.2.2]nonane-4-carboxylic acid, 4-bromophenyl ester), a new selective alpha7 acetylcholine nicotinic receptor (n-AChRs) partial agonist.

Solid-phase syntheses of 6-arylpyridazin-3(2H)-ones.

The 3-chloropyridazine moiety was immobilized on a Wang resin, using two different methodologies. The first of these involved direct nucleophilic substitution of 3,6-dichloropyridazine with the alcoholate of Wang resin. The experimental conditions were optimized.

Design and synthesis of novel imidazo[1,2-a]quinoxalines as PDE4 inhibitors.

New imidazo[1,2-a]quinoxaline derivatives have been synthesised by condensation of an appropriate alpha-aminoalcohol with a quinoxaline followed by intramolecular cyclisation and nucleophilic substitutions. Their phosphodiesterase inhibitory activities have been assessed on a preparation of the PDE4 isoform purified from a human alveolar epithelial cell line (A549). These studies showed potent inhibitory properties that emphasize the importance of a methyl amino group at position 4 and a weakly hindered group at position 1.