ABSTRACT
A class of monomeric nuphar analogues that are either epimeric at C1 and C1' or lack the naturally occurring methyl group at those positions were synthesized and evaluated for biological activity. The syntheses feature enantioselective vinylogous Mukaiyama-Mannich (vM-Mannich) reactions catalyzed by chiral phosphoric acids that proceed with excellent diastereoselectivity. Biological assays reveal that both the desmethyl and C1-epimeric monomeric nuphar analogous are able to induce rapid apoptosis.
Subject(s)
Nuphar/chemistry , Alkaloids/chemistry , Humans , Spectrum Analysis/methods , Stereoisomerism , U937 CellsABSTRACT
Concise, scalable, and enantioselective formal syntheses of eight dimeric and three monomeric nuphar alkaloids were achieved, along with the construction of a stereochemically diverse collection of the first known monomeric analogues having apoptotic activity. The syntheses involved the development of highly enantioselective Brønsted acid catalyzed vinylogous Mukaiyama-Mannich reactions, which feature the unprecedented use of a supersilyl group to control the regio-, enantio- and diastereoselectivity. Biological studies reveal that several of these novel nuphar analogues are even more potent than their dimeric natural product counterparts.
Subject(s)
Alkaloids/chemical synthesis , Apoptosis/drug effects , Alkaloids/chemistry , Alkaloids/pharmacology , Drug Discovery , StereoisomerismABSTRACT
Herein, we describe the first total syntheses of five members of the dimeric nuphar alkaloids: (+)-6,6'-dihydroxythiobinupharidine (+)-1 a, (+)-6-hydroxythiobinupharidine (+)-1 b, (-)-6,6'-dihydroxythionuphlutine (-)-2 a, (-)-6,6'-dihydroxyneothiobinupharidine (-)-3 a, and (+)-6,6'-dihydroxyneothionuphlutine (+)-4 a. The latter two have not been found in nature. We have also made each of their enantiomers (-)-1 a-b, (+)-2 a, (+)-3 a, and (-)-4 a. The key step in these syntheses was the dimerization of an α-aminonitrile (a hydrolytically stable surrogate for its corresponding hemiaminal) with chiral Lewis acid complexes. We have also reassigned the literature structures of (+)-1 a-1 bfor those instances in which the NMR spectra were obtained in CD3ODto their corresponding CD3O-adducts. Our efforts provide for the first time apoptosis data for (-)-3 a, (+)-4 a, and all five non-natural enantiomers prepared. The data indicate high apoptotic activity regardless of the enantiomer or relative stereochemical configuration at C7 and C7'.
Subject(s)
Alkaloids/chemistry , Dimerization , Hydroxylation , Magnetic Resonance Spectroscopy , StereoisomerismABSTRACT
The potent 5-lipoxygenase-activating protein (FLAP) inhibitor 3-[3-tert-butylsulfanyl-1-[4-(6-ethoxypyridin-3-yl)benzyl]-5-(5-methylpyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethylpropionic acid 11cc is described (AM803, now GSK2190915). Building upon AM103 (1) (Hutchinson et al. J. Med Chem.2009, 52, 5803-5815; Stock et al. Bioorg. Med. Chem. Lett. 2010, 20, 213-217; Stock et al. Bioorg. Med. Chem. Lett.2010, 20, 4598-4601), SAR studies centering around the pyridine moiety led to the discovery of compounds that exhibit significantly increased potency in a human whole blood assay measuring LTB(4) inhibition with longer drug preincubation times (15 min vs 5 h). Further studies identified 11cc with a potency of 2.9 nM in FLAP binding, an IC(50) of 76 nM for inhibition of LTB(4) in human blood (5 h incubation) and excellent preclinical toxicology and pharmacokinetics in rat and dog. 11cc also demonstrated an extended pharmacodynamic effect in a rodent bronchoalveolar lavage (BAL) model. This compound has successfully completed phase 1 clinical studies in healthy volunteers and is currently undergoing phase 2 trials in asthmatic patients.
Subject(s)
5-Lipoxygenase-Activating Protein Inhibitors/chemical synthesis , Anti-Asthmatic Agents/chemical synthesis , Indoles/chemical synthesis , Pentanoic Acids/chemical synthesis , 5-Lipoxygenase-Activating Protein Inhibitors/pharmacokinetics , 5-Lipoxygenase-Activating Protein Inhibitors/pharmacology , Administration, Oral , Animals , Anti-Asthmatic Agents/pharmacokinetics , Anti-Asthmatic Agents/pharmacology , Bronchoalveolar Lavage , Cytochrome P-450 Enzyme Inhibitors , Dogs , Female , Humans , In Vitro Techniques , Indoles/pharmacokinetics , Indoles/pharmacology , Male , Pentanoic Acids/pharmacokinetics , Pentanoic Acids/pharmacology , Rats , Rats, Sprague-Dawley , Structure-Activity RelationshipABSTRACT
Compound 21 (AM432) was identified as a potent and selective antagonist of the DP(2) receptor (CRTH2). Modification of a bi-aryl core identified a series of tri-aryl antagonists of which compound 21 proved a viable clinical candidate. AM432 shows excellent potency in a human whole blood eosinophil shape change assay with prolonged incubation, a comparatively long off-rate from the DP(2) receptor, excellent pharmacokinetics in dog and in vivo activity in two mouse models of inflammatory disease after oral dosing.
Subject(s)
Phenylacetates/chemistry , Pyridines/chemistry , Receptors, Immunologic/antagonists & inhibitors , Receptors, Prostaglandin/antagonists & inhibitors , Administration, Oral , Animals , Disease Models, Animal , Dogs , Eosinophils/drug effects , Eosinophils/immunology , Humans , Inflammation/drug therapy , Mice , Phenylacetates/pharmacokinetics , Phenylacetates/therapeutic use , Pyridines/pharmacokinetics , Pyridines/therapeutic use , Receptors, Immunologic/metabolism , Receptors, Prostaglandin/metabolismABSTRACT
AM643 (compound 6, 3-{3-tert-butylsulfanyl-1-[4-(5-methoxy-pyrimidin-2-yl)-benzyl]-5-(5-methyl-pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid) was identified as a potential candidate for formulation as a topical agent for the treatment of skin disorders involving leukotriene production. Dermal application of 6 using a prototypical vehicle in a murine ear arachidonic acid model showed significant reduction in the concentrations of leukotrienes in mouse skin with concomitant reduction in ear swelling.
Subject(s)
Enzyme Inhibitors/chemistry , Indoles/chemical synthesis , Propionates/chemical synthesis , 5-Lipoxygenase-Activating Proteins/metabolism , Administration, Topical , Animals , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/therapeutic use , Humans , Indoles/chemistry , Indoles/therapeutic use , Leukotrienes/biosynthesis , Mice , Propionates/chemistry , Propionates/therapeutic use , Rats , Skin Diseases/chemically induced , Skin Diseases/drug therapyABSTRACT
We evaluated the in vivo pharmacological properties of AM803 3-[3-tert-butylsulfanyl-1-[4-(6-ethoxy-pyridin-3-yl)-benzyl]-5-(5-methyl-pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid, a selective five-lipoxygenase-activating protein (FLAP) inhibitor, using rat and mouse models of acute inflammation. Oral administration of AM803 (1 mg/kg) resulted in sustained inhibition of ex vivo ionophore-challenged whole blood LTB4 biosynthesis with >90% inhibition for up to 12 h and an EC50 of approximately 7 nM. When rat lungs were challenged in vivo with calcium-ionophore, AM803 inhibited LTB4 and cysteinyl leukotriene (CysLT) production with ED50s of 0.12 mg/kg and 0.37 mg/kg, respectively. The inhibition measured 16 h following a single oral dose of 3 mg/kg was 86% and 41% for LTB4 and CysLTs, respectively. In an acute inflammation setting, AM803 dose-dependently reduced LTB4, CysLTs, plasma protein extravasation and neutrophil influx induced by peritoneal zymosan injection. Finally, AM803 increased survival time in mice exposed to a lethal intravenous injection of platelet activating factor (PAF). The magnitude of effect was similar to that of an inhibitor of five-lipoxygenase (5-LO) and LTA4 hydrolase but superior to a leukotriene CysLT1 receptor antagonist. In summary, AM803 is a novel, potent and selective FLAP inhibitor that has excellent pharmacodynamic properties in vivo and is effective in animal models of acute inflammation and in a model of lethal shock.
Subject(s)
Carrier Proteins/antagonists & inhibitors , Indoles/pharmacology , Inflammation/metabolism , Membrane Proteins/antagonists & inhibitors , Pentanoic Acids/pharmacology , Propionates/pharmacology , 5-Lipoxygenase-Activating Proteins , Animals , Chronic Disease , Cysteine/biosynthesis , Disease Models, Animal , Female , Humans , Indoles/pharmacokinetics , Indoles/therapeutic use , Inflammation/drug therapy , Leukotriene B4/biosynthesis , Leukotrienes/biosynthesis , Lung/drug effects , Lung/metabolism , Male , Mice , Pentanoic Acids/pharmacokinetics , Pentanoic Acids/therapeutic use , Platelet Activating Factor/pharmacology , Propionates/pharmacokinetics , Propionates/therapeutic use , Rats , Substrate Specificity , Zymosan/pharmacologyABSTRACT
A series of potent 5-lipoxygenase-activating protein (FLAP) inhibitors are herein described. SAR studies focused on the discovery of novel alicyclic moieties appended to an indole core to optimize potency, physical properties and off-target activities. Subsequent SAR on the N-benzyl substituent of the indole led to the discovery of compound 39 (AM679) which showed potent inhibition of leukotrienes in human blood and in a rodent bronchoalvelolar lavage (BAL) challenge model.
Subject(s)
Carrier Proteins/antagonists & inhibitors , Indoles/chemistry , Lipoxygenase Inhibitors/chemistry , Membrane Proteins/antagonists & inhibitors , Pentanoic Acids/chemistry , 5-Lipoxygenase-Activating Proteins , Animals , Carrier Proteins/metabolism , Humans , Indoles/chemical synthesis , Indoles/pharmacology , Leukotrienes/blood , Leukotrienes/metabolism , Lipoxygenase Inhibitors/chemical synthesis , Lipoxygenase Inhibitors/pharmacology , Membrane Proteins/metabolism , Mice , Models, Animal , Pentanoic Acids/chemical synthesis , Pentanoic Acids/pharmacology , Rats , Structure-Activity RelationshipABSTRACT
The potent and selective 5-lipoxygenase-activating protein leukotriene synthesis inhibitor 3-[3-tert-butylsulfanyl-1-[4-(6-methoxy-pyridin-3-yl)-benzyl]-5-(pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid (11j) is described. Lead optimization was designed to afford compounds with superior in vitro and in vivo inhibition of leukotriene synthesis in addition to having excellent pharmacokinetics and safety in rats and dogs. The key structural features of these new compounds are incorporation of heterocycles on the indole N-benzyl substituent and replacement of the quinoline group resulting in compounds with excellent in vitro and in vivo activities, superior pharmacokinetics, and improved physical properties. The methoxypyridine derivative 11j has an IC(50) of 4.2 nM in a 5-lipoxygenase-activating protein (FLAP) binding assay, an IC(50) of 349 nM in the human blood LTB(4) inhibition assay, and is efficacious in a murine ovalbumin model of allergen-induced asthma. Compound 11j was selected for clinical development and has successfully completed phase 1 trials in healthy volunteers.
Subject(s)
Carrier Proteins/antagonists & inhibitors , Indoles/pharmacokinetics , Leukotriene B4/antagonists & inhibitors , Membrane Proteins/antagonists & inhibitors , Propionates/pharmacokinetics , 5-Lipoxygenase-Activating Proteins , Animals , Asthma/drug therapy , Dogs , Drug-Related Side Effects and Adverse Reactions , Heterocyclic Compounds/chemistry , Humans , Inhibitory Concentration 50 , Leukotriene B4/biosynthesis , Mice , Protein Binding , Rats , Structure-Activity RelationshipABSTRACT
Leukotrienes (LTs) are proinflammatory lipid mediators synthesized by the conversion of arachidonic acid (AA) to LTA(4) by the enzyme 5-lipoxygenase (5-LO) in the presence of 5-LO-activating protein (FLAP). 3-[3-tert-Butylsulfanyl-1-[4-(6-methoxy-pyridin-3-yl)-benzyl]-5-(pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid (AM103) is a novel selective FLAP inhibitor in development for the treatment of respiratory conditions such as asthma. In a rat ex vivo whole-blood calcium ionophore-induced LTB(4) assay, AM103 (administered orally at 1 mg/kg) displayed >50% inhibition for up to 6 h with a calculated EC(50) of approximately 60 nM. When rat lung was challenged in vivo with calcium ionophore, AM103 inhibited LTB(4) and cysteinyl leukotriene (CysLT) production with ED(50) values of 0.8 and 1 mg/kg, respectively. In this model, the EC(50) derived from plasma AM103 was approximately 330 nM for inhibition of both LTB(4) and CysLT. In an acute inflammation setting, AM103 displayed dose-dependent inhibition of LTB(4), CysLT, and plasma protein extravasation induced by peritoneal zymosan injection. In a model of chronic lung inflammation using ovalbumin-primed and challenged BALB/c mice, AM103 reduced the concentrations of eosinophil peroxidase, CysLTs, and interleukin-5 in the bronchoalveolar lavage fluid. Finally, AM103 increased survival time in mice exposed to a lethal intravenous injection of platelet-activating factor. In summary, AM103 is a novel, potent and selective FLAP inhibitor that has excellent pharmacodynamic properties in vivo and is effective in animal models of acute and chronic inflammation and in a model of lethal shock.