An orally active, water-soluble neurokinin-1 receptor antagonist suitable for both intravenous and oral clinical administration.

1-(5-[[(2R,3S)-2-([(1R)-1-[3,5-Bis(trifluoromethyl)phenyl]ethyl]oxy)-3-(4-fluorophenyl)morpholin-4-yl]methyl]-2H-1,2,3-triazol-4-yl)-N,N-dimethylmethanamine hydrochloride 3 is a high affinity, orally active, h-NK(1) receptor antagonist with a long central duration of action and a solubility in water of >100 mg/mL. The construction of the 5-dimethylaminomethyl 1,2,3-triazol-4-yl unit, which incorporates the solubilizing group of 3, was accomplished by thermal rearrangement of a propargylic azide in the presence of dimethylamine. Compound 3 is highly effective in pre-clinical tests that are relevant to clinical efficacy in emesis and depression.

Substituted imidazoles as glucagon receptor antagonists.

A modestly active, nonselective triarylimidazole lead was optimized for binding affinity with the human glucagon receptor. This led to the identification of a 2- and/or 4-alkyl or alkyloxy substituent on the imidazole C4-aryl group as a structural determinant for significant enhancement in binding with the glucagon receptor (e.g., 41, IC(50)=0.053 microM) and selectivity (>1000x) over p38MAP kinase in this class of compounds.

Beta(3)-adrenoceptor agonist-induced increases in lipolysis, metabolic rate, facial flushing, and reflex tachycardia in anesthetized rhesus monkeys.

The effects of two beta(3)-adrenergic receptor agonists, (R)-4-[4-(3-cyclopentylpropyl)-4,5-dihydro-5-oxo-1H-tetrazol-1-yl]-N-[4-[2-[[2-hydroxy-2-(3-pyridinyl)ethyl]amino]ethyl]phenyl]benzenesulfonamide and (R)-N-[4-[2-[[2-hydroxy-2-(3-pyridinyl)- ethyl]amino]ethyl]phenyl]-1-(4-octylthiazol-2-yl)-5-indolinesulfonamide, on indices of metabolic and cardiovascular function were studied in anesthetized rhesus monkeys. Both compounds are potent and specific agonists at human and rhesus beta(3)-adrenergic receptors. Intravenous administration of either compound produced dose-dependent lipolysis, increase in metabolic rate, peripheral vasodilatation, and tachycardia with no effects on mean arterial pressure. The increase in heart rate in response to either compound was biphasic with an initial rapid component coincident with the evoked peripheral vasodilatation and a second more slowly developing phase contemporaneous with the evoked increase in metabolic rate. Because both compounds exhibited weak binding to and activation of rhesus beta(1)-adrenergic receptors in vitro, it was hypothesized that the increase in heart rate may be reflexogenic in origin and proximally mediated via release of endogenous norepinephrine acting at cardiac beta(1)-adrenergic receptors. This hypothesis was confirmed by determining that beta(3)-adrenergic receptor agonist-evoked tachycardia was attenuated in the presence of propranolol and in ganglion-blocked animals, under which conditions there was no reduction in the evoked vasodilatation, lipolysis, or increase in metabolic rate. It is not certain whether the beta(3)-adrenergic receptor-evoked vasodilatation is a direct effect of compounds at beta(3)-adrenergic receptors in the peripheral vasculature or is secondary to the release or generation of an endogenous vasodilator. Peripheral vasodilatation in response to beta(3)-adrenergic receptor agonist administration was not attenuated in animals administered mepyramine, indomethacin, or calcitonin gene-related peptide(8-37). These findings are consistent with a direct vasodilator effect of beta(3)-adrenergic receptor agonists.

Human beta3 adrenergic receptor agonists containing cyanoguanidine and nitroethylenediamine moieties.

Pyridineethanolamine derivatives containing cyanoguanidine or nitroethylenediamine moieties were examined as human beta3 adrenergic receptor (AR) agonists. Notably, indoline derivatives 6a and 11 were potent beta3 AR agonists (beta3 EC50 = 13 and 19 nM, respectively), which showed good selectivity over binding to and minimal activation of the beta1 and beta2 ARs.

The CXCR4 agonist ligand stromal derived factor-1 maintains high affinity for receptors in both Galpha(i)-coupled and uncoupled states.

The alpha chemokine receptor CXCR4 and its only characterized chemokine ligand, stromal cell-derived factor-1 (SDF-1), are postulated to be important in the development of the B-cell arm of the immune system. In addition, CXCR4 is a critical coreceptor in support of viral entry by T-cell line tropic strains (X4) of the Human Immunodeficiency Virus Type 1 (HIV-1), viral variants which predominate in some infected individuals in end stage disease. SDF-1 can block X4-tropic HIV-1 infection of CD4+ target cells in vitro, and allelic variants of the human gene encoding SDF-1 in vivo correlate with delayed disease progression. Therefore, CXCR4 may be an appropriate target for therapeutic intervention in acquired immunodeficiency syndrome (AIDS), and knowledge of the pharmacology of SDF-1 binding to its cognate receptor will be important in the interpretation of these experiments. We report here a Kd derived using a competition binding assay of 4.5 nM for CXCR4 endogenously expressed on peripheral blood monocytes and T-cells. This affinity is similar to that which SDF-1 exhibits when binding to endogenous CXCR4 on an established immortal Jurkat T-cell line as well as recombinant CXCR4 transfected into Chinese Hamster Ovary (CHO) cells. We also demonstrate that the determined affinity of SDF-1 for CXCR4 is reflective of its ability to induce a CXCR4-mediated signal transduction in these different cell types. Furthermore, using Bordetella pertussis toxin, we observe that high affinity binding of SDF-1 to CXCR4 is independent of the G-protein coupled state of the receptor, as uncoupling of G-protein did not lead to the appearance of measurable low affinity SDF-1 binding sites. Moreover, binding affinity and receptor number were unaffected by uncoupling for both recombinant and endogenously expressed CXCR4. Thus, SDF-1 is novel among agonist ligands of G protein-coupled receptors in that it appears to have equal affinity for both the G protein-coupled and uncoupled states of CXCR4.

L-750355, a human beta3-adrenoceptor agonist; in vitro pharmacology and profile of activity in vivo in the rhesus monkey.

The profile of in vitro and in vivo biology of a human beta3-adrenoceptor agonist, (S)-N-[4-[2-[[3[(2-amino-5-pyridinyl)oxy]-2-hydroxy-propyl]amino]-eth yl]-phenyl]-4-isopropylbenzenesulfonamide, L-750355, is described. Using cloned human and rhesus beta1-, beta2- and beta3-adrenoceptors, expressed in Chinese hamster ovary (CHO) cells, L-750355 was shown to be a potent, albeit partial, agonist for the human (EC(50)=10 nM; % maximal receptor activation=49%) and rhesus (EC(50)=28 nM; % maximal receptor activation=34%) beta3-adrenoceptors. Furthermore, L-750355 stimulates lipolysis in rhesus adipocytes in vitro. L-750355 is a weak partial agonist (EC(50)=3.2 microM; % maximal receptor activation=33% ) for the human beta1-adrenoceptor but exhibits no agonist activity for rhesus beta1- or beta2-adrenoceptors of either human or rhesus origin. Administration of L-750355 to anesthetized rhesus monkeys, as a series of rising dose intravenous infusions, evokes dose-dependent glycerolemia and tachycardia with no change in mean arterial blood pressure or plasma potassium. The dose-response curve for L-750355-induced glycerolemia lies to the left of that for tachycardia. Propranolol, at a dose (0.3 mg/kg, i.v. ) that attenuates isoproterenol-induced changes in heart rate and glycerolemia, abolished L-750355-induced tachycardia but had no effect on L-750355-induced glycerolemia.

Discovery of a potent, orally bioavailable beta(3) adrenergic receptor agonist, (R)-N-[4-[2-[[2-hydroxy-2-(3-pyridinyl)ethyl]amino]ethyl]phenyl]-4-[4 -[4-(trifluoromethyl)phenyl]thiazol-2-yl]benzenesulfonamide.

As part of our investigation into the development of orally bioavailable beta(3) adrenergic receptor agonists, we have identified a series of pyridylethanolamine analogues possessing a substituted thiazole benzenesulfonamide pharmacophore that are potent human beta(3) agonists with excellent selectivity against other human beta receptor subtypes. Several of these compounds also exhibited an improved pharmacokinetic profile in dogs. For example, thiazole sulfonamide 2e (R = 4-F(3)C-C(6)H(4)) is a potent full beta(3) agonist (EC(50) = 3.6 nM, 94% activation) with >600-fold selectivity over the human beta(1) and beta(2) receptors, which also displays good oral bioavailability in several mammalian species, as well as an extended duration of action.

Tetrahydroisoquinoline derivatives containing a benzenesulfonamide moiety as potent, selective human beta3 adrenergic receptor agonists.

Tetrahydroisoquinoline derivatives containing a 4-(hexylureido)benzenesulfonamide were examined as human beta3 adrenergic receptor (AR) agonists. Notably, 4,4-biphenyl derivative 9 was a 6 nM full agonist of the beta3 AR. Naphthyloxy compound 18 (beta3 EC50 = 78 nM) did not activate the beta1 and beta2 ARs at 10 microM, and showed >1000-fold selectivity over binding to the beta1 and beta2 ARs.

Potent, selective 3-pyridylethanolamine beta3 adrenergic receptor agonists possessing a thiazole benzenesulfonamide pharmacophore.

A series of thiazole benzenesulfonamide-substituted 3-pyridylethanolamines was prepared and evaluated for their human beta3 adrenergic receptor agonist activity. Incorporation of aryl and heteroaryl substitution in the 4-position of the thiazole ring resulted in a number of highly potent and selective beta3 agonists. Results of preliminary in vivo evaluation of several of these compounds is described.

Human beta3-adrenergic receptor agonists containing 1,2,3-triazole-substituted benzenesulfonamides.

Compounds containing a 1,2,3-triazole-substituted benzenesulfonamide were prepared and found to be potent and selective human beta3-adrenergic receptor agonists. The most interesting compound, trifluoromethylbenzyl analogue 12e (beta3 EC50 = 3.1 nM with >1500-fold selectivity over binding to both beta1- and beta2 receptors), stimulates lipolysis in the rhesus monkey (ED50 = 0.36 mg/kg) and is 25% orally bioavailable in the dog.

The chemokine/chemokine-receptor family: potential and progress for therapeutic intervention.

The chemokines are a large superfamily of chemotactic cytokines that are utilized to direct the trafficking and migration of leukocytes within the immune system. The chemokines mediate their activity through a large family of G-protein-coupled receptors, and thus are highly tractable as therapeutic targets. Exciting advances have been made in the field within the past year, not the least of which is the disclosure of potent antagonists of several chemokine receptors. Several CCR5 antagonists have demonstrated potent antiviral activity and may represent novel therapeutic agents for the treatment of AIDS. In addition, new biological insights have been gained from the demonstration that the targeting of cells to inflammatory sites is tissue specific, such that different chemokine/chemokine-receptor pairs are utilized in recruitment of T-lymphocytes to the skin and to the intestine. Also, utilization of neutralizing antibodies to the CXCR3 ligand Mig in murine allograft transplantation models has demonstrated the importance of CXCR3 in orchestrating T-cell-mediated tissue rejection.

Substituted oxazole benzenesulfonamides as potent human beta3 adrenergic receptor agonists.

As a part of our investigation into the development of orally bioavailable beta3 adrenergic receptor agonists, we have identified a series of substituted oxazole derivatives that are potent beta3 agonists with excellent selectivity against other beta receptors. Several of these compounds showed excellent oral bioavailability in dogs. One example, cyclopentylethyloxazole 5f is a potent beta3 agonist (EC50 = 14 nM, 84% activation) with 340-fold and 160-fold selectivity over beta1 and beta2 receptors, respectively, and has 38% oral bioavailability in dogs.

Discovery of an orally bioavailable alkyl oxadiazole beta3 adrenergic receptor agonist.

5-n-Pentyl oxadiazole substituted benzenesulfonamide 8 is a potent and selective beta3 adrenergic receptor agonist (beta3 EC50 = 23 nM, beta1 IC50 = 3000 nM, beta2 IC50 = 3000 nM). The compound has high oral bioavailability in dogs (62%) and rats (36%) and is among the most orally bioavailable beta3 adrenergic receptor agonists reported to date.

Synthesis and SAR of benzyl and phenoxymethylene oxadiazole benzenesulfonamides as selective beta3 adrenergic receptor agonist antiobesity agents.

Benzyl and phenoxymethylene substituted oxadiazoles are potent and orally bioavailable beta3 adrenergic receptor (AR) agonists. The 4-trifluormethoxy substituted 5-benzyl oxadiazole 5f has an EC50 of 8 nM in the beta3 AR agonist assay with 100-fold selectivity over beta1 and beta2 AR binding inhibition activity. Its oral bioavailability in dogs is 30 +/- 4%, with a half-life of 3.8 +/- 0.4 h. In the anesthetized rhesus, 5f evoked a dose-dependent glycerolemia (ED50Gly = 0.15 mg/kg). Under these conditions a heart rate increase of 15% was observed at a dose level of 10 mg/kg.

Phosphorylated morpholine acetal human neurokinin-1 receptor antagonists as water-soluble prodrugs.

The regioselective dibenzylphosphorylation of 2 followed by catalytic reduction in the presence of N-methyl-D-glucamine afforded 2-(S)-(1-(R)-(3, 5-bis(trifluoromethyl)phenyl)ethoxy)-3-(S)-(4-fluoro)phenyl-4-(5-(2- phosphoryl-3-oxo-4H,-1,2,4-triazolo)methylmorpholine, bis(N-methyl-D-glucamine) salt, 11. Incubation of 11 in rat, dog, and human plasma and in human hepatic subcellular fractions in vitro indicated that conversion to 2 would be expected to occur in vivo most readily in humans during hepatic circulation. Conversion of 11 to 2 occurred rapidly in vivo in the rat and dog with the levels of 11 being undetectable within 5 min after 1 and 8 mg/kg doses iv in the rat and within 15 min after 0.5, 2, and 32 mg/kg doses iv in the dog. Compound 11 has a 10-fold lower affinity for the human NK-1 receptor as compared to 2, but it is functionally equivalent to 2 in preclinical models of NK-1-mediated inflammation in the guinea pig and cisplatin-induced emesis in the ferret, indicating that 11 acts as a prodrug of 2. Based in part on these data, 11 was identified as a novel, water-soluble prodrug of the clinical candidate 2 suitable for intravenous administration in humans.

Potent and selective human beta(3)-adrenergic receptor antagonists.

Although the functional presence of beta(3)-adrenergic receptors (beta(3)-AR) in rodents is well established, its significance in human adipose tissue has been controversial. One of the issues confounding the experimental data has been the lack of potent and selective human beta(3)-AR ligands analogous to the rodent-specific agonist BRL37344. Recently, we described a new class of aryloxypropanolamine beta(3)-AR agonists that potently and selectively activate lipolysis in rhesus isolated adipocytes and stimulate the metabolic rate in rhesus monkeys in vivo. In this article, we describe novel and selective beta(3)-AR antagonists with high affinity for the human receptor. L-748,328 and L-748,337 bind the human cloned beta(3)-AR expressed in Chinese hamster ovary (CHO) cells with an affinity of 3.7 +/- 1.4 and 4.0 +/- 0.4 nM, respectively. They display an affinity of 467 +/- 89 and 390 +/- 154 nM for the human beta(1)-AR. Their selectivity for human beta(3)-AR versus beta(2)-AR is greater than 20-fold (99 +/- 43 nM) and 45-fold (204 +/- 75 nM), respectively. These compounds are competitive antagonists capable of inhibiting the functional activation of agonists in a dose-dependent manner in cells expressing human cloned beta(3)-AR. Moreover, both L-748,328 and L-748,337 inhibit the lipolytic response elicited by the beta(3)-AR agonist L-742,791 in isolated nonhuman primate adipocytes. The aryloxypropanolamine benzenesulfonamide ligands illustrated here and elsewhere demonstrate high-affinity human beta(3)-AR binding. In addition, we describe specific 3'-phenoxy substitutions that transform these compounds from potent agonists into selective antagonists.

Potent, elective human beta3 adrenergic receptor agonists containing a substituted indoline-5-sulfonamide pharmacophore.

A series of compounds possessing an N-substituted indoline-5-sulfonamide pharmacophore was prepared and evaluated for their human beta3 adrenergic receptor agonist activity. The SAR of a wide range of urea and heterocyclic substituents is discussed. 4-Octyl thiazole compound 8c was the most potent and selective compound in the series, with 2800-fold selectivity over beta1 binding and 1400-fold selectivity over beta2 binding.

Receptor for motilin identified in the human gastrointestinal system.

Motilin is a 22-amino acid peptide hormone expressed throughout the gastrointestinal (GI) tract of humans and other species. It affects gastric motility by stimulating interdigestive antrum and duodenal contractions. A heterotrimeric guanosine triphosphate-binding protein (G protein)-coupled receptor for motilin was isolated from human stomach, and its amino acid sequence was found to be 52 percent identical to the human receptor for growth hormone secretagogues. The macrolide antibiotic erythromycin also interacted with the cloned motilin receptor, providing a molecular basis for its effects on the human GI tract. The motilin receptor is expressed in enteric neurons of the human duodenum and colon. Development of motilin receptor agonists and antagonists may be useful in the treatment of multiple disorders of GI motility.

L-770,644: a potent and selective human beta3 adrenergic receptor agonist with improved oral bioavailability.

L-770,644 (9c) is a potent and selective agonist of the human beta3 adrenergic receptor (EC50 = 13 nM). It shows good oral bioavailability in both dogs and rats (%F = 27), and is a full agonist for glycerolemia in the rhesus monkey (ED50 = 0.21 mg/kg). Based on its desirable in vitro and in vivo properties, L-770,644 was chosen for further preclinical evaluation.