Antiobesity effect of MK-5046, a novel bombesin receptor subtype-3 agonist.

Bombesin receptor subtype-3 (BRS-3) is an orphan G protein-coupled receptor implicated in the regulation of energy homeostasis. Here, we report the biologic effects of a highly optimized BRS-3 agonist, (2S)-1,1,1-trifluoro-2-[4-(1H-pyrazol-1-yl)phenyl]-3-(4-{[1-(trifluoromethyl)cyclopropyl]methyl}-1H-imidazol-2-yl)propan-2-ol (MK-5046). Single oral doses of MK-5046 inhibited 2-h and overnight food intake and increased fasting metabolic rate in wild-type but not Brs3 knockout mice.

Dihydro-pyrano[2,3-b]pyridines and tetrahydro-1,8-naphthyridines as CB1 receptor inverse agonists: synthesis, SAR and biological evaluation.

Synthesis and structure-activity relationships of cannabinoid-1 receptor (CB1R) inverse agonists based on dihydro-pyrano[2,3-b] pyridine and tetrahydro-1,8-naphtyridine scaffolds are presented. Rat food intake and pharmacokinetic evaluation of 13g, 13i, 13k and 17a revealed these compounds to be highly efficacious orally active modulators of CB1R.

Discovery of N-[(4R)-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-2,2-dimethyl-3,4-dihydro-2H-pyrano[2,3-b]pyridin-4-yl]-5-methyl-1H-pyrazole-3-carboxamide (MK-5596) as a novel cannabinoid-1 receptor (CB1R) inverse agonist for the treatment of obesity.

This paper describes the discovery of N-[(4R)-6-(4-chlorophenyl)-7-(2,4-dichlorophenyl)-2,2-dimethyl-3,4-dihydro-2H-pyrano[2,3-b]pyridin-4-yl]-5-methyl-1H-pyrazole-3-carboxamide (MK-5596, 12c) as a novel cannabinoid-1 receptor (CB1R) inverse agonist for the treatment of obesity. Structure-activity relationship (SAR) studies of lead compound 3, which had off-target hERG (human ether-a-go-go related gene) inhibition activity, led to the identification of several compounds that not only had attenuated hERG inhibition activity but also were subject to glucuronidation in vitro providing the potential for multiple metabolic clearance pathways. Among them, pyrazole 12c was found to be a highly selective CB1R inverse agonist that reduced body weight and food intake in a DIO (diet-induced obese) rat model through a CB1R-mediated mechanism.

Discovery of substituted biphenyl imidazoles as potent, bioavailable bombesin receptor subtype-3 agonists.

We report SAR studies on a novel non-peptidic bombesin receptor subtype-3 (BRS-3) agonist lead series derived from high-throughput screening hit RY-337. This effort led to the discovery of compound 22e with significantly improved potency at both rodent and human BRS-3.

Furo[2,3-b]pyridine-based cannabinoid-1 receptor inverse agonists: synthesis and biological evaluation. Part 1.

The synthesis, SAR and binding affinities of cannabinoid-1 receptor (CB1R) inverse agonists based on furo[2,3-b]pyridine scaffolds are described. Food intake, mechanism specific efficacy, pharmacokinetic, and metabolic evaluation of several of these compounds indicate that they are effective orally active modulators of CB1R.

Pyridopyrimidine based cannabinoid-1 receptor inverse agonists: Synthesis and biological evaluation.

The synthesis, SAR and binding affinities are described for cannabinoid-1 receptor (CB1R) specific inverse agonists based on pyridopyrimidine and heterotricyclic scaffolds. Food intake and pharmacokinetic evaluation of several of these compounds indicate that they are effective orally active modulators of CB1R.

Characterization of a novel and selective cannabinoid CB1 receptor inverse agonist, Imidazole 24b, in rodents.

We document in vitro and in vivo effects of a novel, selective cannabinoid CB(1) receptor inverse agonist, Imidazole 24b (5-(4-chlorophenyl)-N-cyclohexyl-4-(2,4-dichlorophenyl)-1-methyl-imidazole-2-carboxamide). The in vitro binding affinity of Imidazole 24b for recombinant human and rat CB(1) receptor is 4 and 10 nM, respectively. Imidazole 24b binds to human cannabinoid CB(2) receptor with an affinity of 297 nM; in vitro, it is a receptor inverse agonist at both cannabinoid CB(1) and CB(2) receptors as it causes a further increase of forskolin-induced cAMP increase.

Antiobesity efficacy of a novel cannabinoid-1 receptor inverse agonist, N-[(1S,2S)-3-(4-chlorophenyl)-2-(3-cyanophenyl)-1-methylpropyl]-2-methyl-2-[[5-(trifluoromethyl)pyridin-2-yl]oxy]propanamide (MK-0364), in rodents.

The cannabinoid-1 receptor (CB1R) has been implicated in the control of energy balance. To explore the pharmacological utility of CB1R inhibition for the treatment of obesity, we evaluated the efficacy of N-[(1S,2S)-3-(4-chlorophenyl)-2-(3-cyanophenyl)-1-methylpropyl]-2-methyl-2-[[5-(trifluoromethyl)pyridin-2-yl]oxy]propanamide (MK-0364) and determined the relationship between efficacy and brain CB1R occupancy in rodents. MK-0364 was shown to be a highly potent CB1R inverse agonist that inhibited the binding and functional activity of various agonists with a binding K(i) of 0.

Substituted acyclic sulfonamides as human cannabinoid-1 receptor inverse agonists.

Sulfonamide analogues of the potent CB1R inverse agonist taranabant were prepared and optimized for potency and selectivity for CB1R. They were variably more potent than the corresponding amide analogues. The most potent representative 22 had good pharmacokinetic and brain levels, but was modestly active in blocking CB1R agonist-mediated hypothermia.

Lead optimization of 5,6-diarylpyridines as CB1 receptor inverse agonists.

Optimization of the biological activity for 5,6-diarylpyridines as CB1 receptor inverse agonists is described. Food intake and pharmacokinetic evaluation of 3f and 15c indicate that these compounds are effective orally active modulators of CB1.

Discovery of N-[(1S,2S)-3-(4-Chlorophenyl)-2- (3-cyanophenyl)-1-methylpropyl]-2-methyl-2- {[5-(trifluoromethyl)pyridin-2-yl]oxy}propanamide (MK-0364), a novel, acyclic cannabinoid-1 receptor inverse agonist for the treatment of obesity.

The discovery of novel acyclic amide cannabinoid-1 receptor inverse agonists is described. They are potent, selective, orally bioavailable, and active in rodent models of food intake and body weight reduction. A major focus of the optimization process was to increase in vivo efficacy and to reduce the potential for formation of reactive metabolites.

Ghrelin neutralization by a ribonucleic acid-SPM ameliorates obesity in diet-induced obese mice.

Ghrelin, an acylated peptide secreted from the stomach, acts as a short-term signal of nutrient depletion. Ghrelin is an endogenous ligand for the GH secretagogue receptor 1a, a G protein-coupled receptor expressed in the hypothalamus and pituitary. We used a synthetic oligonucleotide, NOX-B11-2, capable of specific high-affinity binding to bioactive ghrelin to determine whether ghrelin neutralization would alter indices of energy balance in vivo.

Synthesis of functionalized 1,8-naphthyridinones and their evaluation as novel, orally active CB1 receptor inverse agonists.

Synthesis, SAR, and binding affinities are described for a new class of 1,8-naphthyridinone CB1 receptor specific inverse agonists. Food intake, knockout mouse, and pharmacokinetic evaluation of 14 indicate that this compound is an effective orally active modulator of CB1.

Synthesis and activity of 4,5-diarylimidazoles as human CB1 receptor inverse agonists.

Structure-activity relationship studies directed toward the optimization of 4,5-diarylimidazole-2-carboxamide analogs as human CB1 receptor inverse agonists resulted in the discovery of the two amide derivatives 24a and b (hCB1 IC50 = 6.1 and 4.0 nM) which also demonstrated efficacy in overnight feeding studies in the rat for reduction in both food intake and overall body weight.

Synthesis and SAR of 5,6-diarylpyridines as human CB1 inverse agonists.

Structure-activity relationship studies for two series of 2-benzyloxy-5-(4-chlorophenyl)-6-(2,4-dichlorophenyl)pyridines having either a 3-cyano or 3-carboxamide moiety resulted in the preparation of the 2-(3,4-difluorobenzyloxy)-3-nitrile analog 10d and the 2-(3,4-difluorobenzyloxy)-3-(N-propylcarboxamide) analog 16c, (hCB1 IC(50)=1.3 and 1.7 nM, respectively) as potent and selective hCB1 inverse agonists.

Enhanced running wheel activity of both Mch1r- and Pmch-deficient mice.

Mch1r-deficient (Mch1r(-/-)) mice are hyperphagic, hyperactive, lean, and resistant to diet-induced obesity. To examine whether the MCH1R is involved in regulating activity-based energy expenditure, we investigated voluntary wheel running (WR) activity of wild-type (WT) and Mch1r(-/-) mice basally, in response to diets with different caloric density and with different feeding schedules. We also evaluated WR activity of mice with ablation of the prepro-MCH gene (Pmch(-/-) mice).

Voluntary exercise augments acute effects of CB1-receptor inverse agonist on body weight loss in obese and lean mice.

Cannabinoid CB1 receptor (CB1R) inverse agonists reduce appetite and body weight (BW) gain in various species. Exercise is thought to be a natural reward process and the cannabinoid system is also believed to influence reward. We tested the hypothesis that voluntary exercise would augment the effects of AM251, a CB1R inverse agonist, on food intake (FI) and BW loss in murine genetic models of obesity.

Chronic MCH-1 receptor modulation alters appetite, body weight and adiposity in rats.

Central administration of the neuropeptide melanin-concentrating hormone (MCH) stimulates feeding in rodents. We studied the effects of intracerebroventricular (i.c.

Neither agouti-related protein nor neuropeptide Y is critically required for the regulation of energy homeostasis in mice.

Agouti-related protein (AgRP), a neuropeptide abundantly expressed in the arcuate nucleus of the hypothalamus, potently stimulates feeding and body weight gain in rodents. AgRP is believed to exert its effects through the blockade of signaling by alpha-melanocyte-stimulating hormone at central nervous system (CNS) melanocortin-3 receptor (Mc3r) and Mc4r. We generated AgRP-deficient (Agrp(-/-)) mice to examine the physiological role of AgRP.

Melanin-concentrating hormone 1 receptor-deficient mice are lean, hyperactive, and hyperphagic and have altered metabolism.

Melanin-concentrating hormone (MCH) is a cyclic 19-aa hypothalamic neuropeptide derived from a larger prohormone precursor of MCH (Pmch), which also encodes neuropeptide EI (NEI) and neuropeptide GE (NGE). Pmch-deficient (Pmch-/-) mice are lean, hypophagic, and have an increased metabolic rate. Transgenic mice overexpressing Pmch are hyperphagic and develop mild obesity.