RESUMEN
A structure-activity relationship study was undertaken to address the lack of oral exposure of the H3 antagonist 1, which incorporated an arylketone. Among a number of sub-series, the 4H-pyrido[1,2-a]pyrimidin-4-one analog 21 showed an improved PK profile in rat and mouse and was active in an obesity model. The pyrimidin-4-one proved to be a novel and useful ketone bioisostere.
Asunto(s)
Antagonistas de los Receptores Histamínicos H3/farmacocinética , Tiadiazoles/farmacología , Administración Oral , Animales , Cetonas , Obesidad/tratamiento farmacológico , Ratas , Relación Estructura-Actividad , Tiadiazoles/farmacocinéticaRESUMEN
The synthesis and SAR of a novel series of 4-azabenzoxazole histamine H(3) antagonists is described. Introduction of substituted phenyl, pyridyl and fused heterocyclic groups to the 6-position of the 4-azabenzoxazole core gave a series of compounds with good H(3) antagonist activity in both ex vivo and in vivo assays.
Asunto(s)
Benzoxazoles/química , Benzoxazoles/farmacología , Antagonistas de los Receptores Histamínicos H3/química , Antagonistas de los Receptores Histamínicos H3/farmacología , Receptores Histamínicos H3/metabolismo , Animales , Compuestos Aza/síntesis química , Compuestos Aza/química , Compuestos Aza/farmacocinética , Compuestos Aza/farmacología , Benzoxazoles/síntesis química , Benzoxazoles/farmacocinética , Antagonistas de los Receptores Histamínicos H3/síntesis química , Antagonistas de los Receptores Histamínicos H3/farmacocinética , Humanos , Ratones , Ratas , Relación Estructura-ActividadRESUMEN
A series of novel 2-piperidinopiperidine thiadiazoles were synthesized and evaluated as new leads of histamine H3 receptor antagonists. The 4-(5-([1,4'-bipiperidin]-1'-yl)-1,3,4-thiadiazol-2-yl)-2-(pyridin-2-yl)morpholine (5u) displayed excellent potency and ex vivo receptor occupancy. Compound 5u was also evaluated in vivo for antidiabetic efficacy in STZ diet-induced obesity type 2 diabetic mice for 2 or 12 days. Non-fasting glucose levels were significantly reduced as compared with vehicle-treated mice. In addition, 5u dose dependently blocked the increase of HbA1c after 12 days of treatment.
RESUMEN
A series of 2-piperidinopiperidine-5-arylthiadiazoles was synthesized and subjected to a structure-activity relationship (SAR) investigation. The potency of this series was improved to the single digit nanomolar range. The key analogs were shown to be free of P450 issues, and they also maintained good ex vivo activity and brain penetration.
Asunto(s)
Antagonistas de los Receptores Histamínicos/química , Antagonistas de los Receptores Histamínicos/farmacología , Receptores Histamínicos H3/metabolismo , Tiadiazoles/química , Tiadiazoles/farmacología , Animales , Encéfalo/metabolismo , Antagonistas de los Receptores Histamínicos/farmacocinética , Humanos , Ratones , Ratas , Relación Estructura-Actividad , Tiadiazoles/farmacocinéticaRESUMEN
A series of 2-(1,4'-bipiperidine-1'-yl)thiazolopyridines was synthesized and evaluated as a new lead of non-imidazole histamine H(3) receptor antagonists. Introduction of diversity at the 6-position of the pyridine ring was designed to enhance in vitro potency and decrease hERG activity. The structure-activity relationships for these new thiazolopyridine antagonists are discussed.
Asunto(s)
Antagonistas de los Receptores Histamínicos/química , Piridinas/química , Receptores Histamínicos H3/química , Animales , Haplorrinos , Antagonistas de los Receptores Histamínicos/síntesis química , Antagonistas de los Receptores Histamínicos/farmacocinética , Humanos , Ratones , Ratones Endogámicos ICR , Microsomas Hepáticos/metabolismo , Piridinas/síntesis química , Piridinas/farmacocinética , Ratas , Receptores Histamínicos H3/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Relación Estructura-Actividad , Transactivadores/metabolismo , Regulador Transcripcional ERGRESUMEN
A novel series of histamine H3 receptor antagonists based on the 4-[(1H-imidazol-4-yl)methyl]piperidine template displaying low CYP2D6 and CYP3A4 inhibitory profiles has been identified. Structural features responsible for the reduction of P450 activity, a typical liability of 4-substituted imidazoles, have been established.
Asunto(s)
Inhibidores Enzimáticos del Citocromo P-450 , Inhibidores Enzimáticos/farmacología , Antagonistas de los Receptores Histamínicos/farmacología , Imidazoles/farmacología , Piperidinas/farmacología , Receptores Histamínicos H3/efectos de los fármacos , Animales , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Cobayas , Haplorrinos , Antagonistas de los Receptores Histamínicos/síntesis química , Antagonistas de los Receptores Histamínicos/química , Humanos , Imidazoles/síntesis química , Imidazoles/química , Estructura Molecular , Piperidinas/síntesis química , Piperidinas/química , Ratas , Relación Estructura-Actividad , Distribución TisularRESUMEN
We report the discovery of novel histamine H(3) receptor antagonists based on 4-[(1H-imidazol-4-yl)methyl]piperidine. The most potent compounds in the series (e.g., 7) result from the attachment of a substituted aniline amide to the main pharmacophore piperidine via a two-methylene linker.
Asunto(s)
Antagonistas de los Receptores Histamínicos/farmacología , Imidazoles/farmacología , Piperidinas/farmacología , Receptores Histamínicos H3/efectos de los fármacos , Inhibidores del Citocromo P-450 CYP2D6 , Evaluación Preclínica de Medicamentos , Antagonistas de los Receptores Histamínicos/síntesis química , Antagonistas de los Receptores Histamínicos/química , Humanos , Imidazoles/síntesis química , Imidazoles/química , Técnicas In Vitro , Estructura Molecular , Piperidinas/síntesis química , Piperidinas/química , Relación Estructura-ActividadRESUMEN
BACKGROUND: The human histamine H1 receptor is constitutively active and exhibits basal activation of nuclear factor-kappaB (NF-kappaB), an important modulator of allergic inflammation. Certain H1 antihistamines have recently been shown to inhibit basal NF-kappaB activity by stabilizing the H1 receptor in an inactive state, a phenomenon called 'inverse agonism'. METHODS: We evaluated the effect of the new H1 antihistamine, desloratadine, on basal and histamine-stimulated NF-kappaB activity and compared it with the activities of other H1 antihistamines. RESULTS: Transiently transfected COS-7 cells co-expressing NF-kappaB-luciferase and the H1 receptor exhibited constitutive NF-kappaB activity. H1 antihistamines reduced basal NF-kappaB activity (rank order of potency: desloratadine > pyrilamine > cetirizine > loratadine > fexofenadine). Histamine stimulated basal NF-kappaB activity 8-fold, which was blocked by H1 antihistamines (rank order of potency: desloratadine > cetirizine > pyrilamine > loratadine > fexofenadine). Neither histamine nor antihistamines had any effect on NF-kappaB activity in the absence of the H1 receptor. CONCLUSIONS: Desloratadine, acting through the histamine H1 receptor, inhibited basal NF-kappaB activity and can thus be classified as an inverse agonist. Inhibition of basal and histamine-stimulated NF-kappaB activity may help to explain previously reported inhibitory effects of desloratadine on allergic inflammatory mediators.
Asunto(s)
Antagonistas de los Receptores Histamínicos H1/farmacología , Histamina/farmacología , Loratadina/análogos & derivados , Loratadina/farmacología , FN-kappa B/antagonistas & inhibidores , Receptores Histamínicos H1/inmunología , Animales , Células COS , Chlorocebus aethiops , Histamina/inmunología , Agonistas de los Receptores Histamínicos/inmunología , Agonistas de los Receptores Histamínicos/farmacología , Antagonistas de los Receptores Histamínicos H1/inmunología , Humanos , Concentración 50 Inhibidora , Loratadina/inmunología , FN-kappa B/inmunologíaRESUMEN
Combining the first generation H(1) antihistamine chlorpheniramine (1) with H(3) ligands of the alkylamine type has led to the identification of compound 9d, a dual ligand of both the H(1) and H(3) receptors.