RESUMEN
Rhizopus delemar lipase catalysed ester hydrolysis of the alpha-methoxy-beta-phenylpropanoate 1 affords the (R)-(+) and (S)-(-) isomers in > 84% enantiomeric excess. Absolute stereochemistry was determined by a single crystal X-ray analysis of a related synthetic analogue. The activity of these two enantiomers on glucose transport in vitro and as anti-diabetic agents in vivo is reported and their unexpected equivalence attributed to an enzyme-mediated stereospecific isomerisation of the (R)-(+) isomer. Binding studies using recombinant human PPARgamma (peroxisomal proliferator activated receptor gamma), now established as a molecular target for this compound class, indicate a 20-fold higher binding affinity for the (S) antipode relative to the (R) antipode.
Asunto(s)
Hipoglucemiantes/síntesis química , Hipoglucemiantes/farmacología , Fenilpropionatos/síntesis química , Animales , Cristalografía por Rayos X , Modelos Químicos , Modelos Moleculares , Ratas , Receptores Citoplasmáticos y Nucleares/metabolismo , Estereoisomerismo , Factores de Tiempo , Factores de Transcripción/metabolismoRESUMEN
A radioiodinated ligand, [125I]SB-236636 [(S)-(-)3-[4-[2-[N-(2-benzoxazolyl)-N-methylamino]ethoxy]3-[125I]i odo phenyl]2-ethoxy propanoic acid], which is specific for the gamma isoform of the peroxisomal proliferator activated receptor (PPARgamma), was developed. [125I]SB-236636 binds with high affinity to full-length human recombinant PPARgamma1 and to a GST (glutathione S-transferase) fusion protein containing the ligand binding domain of human PPARgamma1 (KD = 70 nM). Using this ligand, we characterized binding sites in adipose-derived cells from rat, mouse and humans. In competition experiments, rosiglitazone (BRL-49653), a potent antihyperglycemic agent, binds with high affinity to sites in intact adipocytes (IC50 = 12, 4 and 9 nM for rat, 3T3-L1 and human adipocytes, respectively). Binding affinities (IC50) of other thiazolidinediones for the ligand binding domain of PPARgamma1 were comparable with those determined in adipocytes and reflected the rank order of potencies of these agents as stimulants of glucose transport in 3T3-L1 adipocytes and antihyperglycemic agents in vivo: rosiglitazone > pioglitazone > troglitazone. Competition of [125I]SB-236636 binding was stereoselective in that the IC50 value of SB-219994, the (S)-enantiomer of an alpha-trifluoroethoxy propanoic acid insulin sensitizer, was 770-fold lower than that of SB-219993 [(R)-enantiomer] at recombinant human PPARgamma1. The higher binding affinity of SB-219994 also was evident in intact adipocytes and reflected its 100-fold greater potency as an antidiabetic agent. The results strongly suggest that the high-affinity binding site for [125I]SB-236636 in intact adipocytes is PPARgamma and that the pharmacology of insulin-sensitizer binding in rodent and human adipocytes is very similar and, moreover, predictive of antihyperglycemic activity in vivo.
Asunto(s)
Adipocitos/metabolismo , Benzoxazoles/metabolismo , Hipoglucemiantes/farmacología , Fenilpropionatos/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Tiazoles/metabolismo , Tiazolidinedionas , Factores de Transcripción/metabolismo , Células 3T3 , Animales , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Ensayo de Unión Radioligante , Ratas , Ratas Sprague-Dawley , Proteínas Recombinantes , Rosiglitazona , Relación Estructura-ActividadRESUMEN
A series of [(ureidoethoxy)benzyl]-2,4-thiazolidinediones and [[(heterocyclylamino)alkoxy]-benzyl]-2,4-thiazolidinediones was synthesized from the corresponding aldehydes. Compounds from the urea series, exemplified by 16, showed antihyperglycemic potency comparable with known agents of the type such as pioglitazone and troglitazone (CS-045). The benzoxazole 49, a cyclic analogue of 16, was a very potent enhancer of insulin sensitivity, and by modification of the aromatic heterocycle, an aminopyridine, 37, was identified as a lead compound from SAR studies. Evaluation of antihyperglycemic activity together with effects on blood hemoglobin content, to determine the therapeutic index, was performed in 8-day repeat administration studies in genetically obese C57 Bl/6 ob/ob mice. From these studies, BRL 49653 (37) has been selected, on the basis of antihyperglycemic potency combined with enhanced selectivity against reductions in blood hemoglobin content, for further evaluation.
Asunto(s)
Hipoglucemiantes/farmacología , Tiazoles/farmacología , Animales , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Modelos Animales de Enfermedad , Hemoglobinas/análisis , Hipoglucemiantes/uso terapéutico , Ratones , Ratones Endogámicos C57BL , Relación Estructura-Actividad , Tiazoles/uso terapéuticoRESUMEN
The RR-enantiomer of the beta 3-adrenergic receptor agonist BRL 37344 was tritiated to yield a high specific activity compound, [3H]SB 206606. This new, potentially specific, beta 3-adrenergic receptor ligand was characterized by binding studies using membranes from both Chinese hamster ovary K1 cells transfected with the rat beta 3-adrenergic receptor and rat interscapular brown adipose tissue, where beta 1-, beta 2-, and beta 3-adrenergic receptor subtypes are known to coexist. [3H]SB 206606 was found to bind to a single population of binding sites in both preparations. The Kd values for [3H]SB 206606 binding to membranes from Chinese hamster ovary K1 cells and brown adipose tissue were quite comparable (58 and 38 nM, respectively). At 37 degrees, the time courses of association and dissociation of [3H]SB 206606 with membranes of brown adipose tissue were quite short. At 4 degrees, the T1/2 were found to be 13 and 40 min, respectively. The Ki values for various beta-adrenergic agonists and antagonists in brown adipose tissue membranes were similar to those obtained in Chinese hamster ovary K1 cell membranes with both [3H]SB 206606 and [125I]iodocyanopindolol. The order of binding affinity was BRL 37344 >> (-)-isoproterenol = (-)-norepinephrine > (-)-epinephrine = (+)-isoproterenol. The similarity of the Kd values and of the Ki values for various beta-adrenergic agonists and antagonists in both systems tested indicates that, in a complex membrane system, [3H]SB 206606 binds selectively to the beta 3-adrenergic receptor. The affinity of [3H]SB 206606 is 76 times higher for the beta 3-adrenergic receptor than for the beta 1/beta 2-adrenergic receptors, thus allowing, under controlled conditions, measurement of interactions only with the beta 3-adrenergic receptor in complex membrane systems.
Asunto(s)
Etanolaminas/metabolismo , Receptores Adrenérgicos beta/metabolismo , Tejido Adiposo Pardo/metabolismo , Animales , Células CHO , Cricetinae , Cricetulus , Masculino , Estructura Molecular , Ensayo de Unión Radioligante , Ratas , Ratas Sprague-Dawley , Receptores Adrenérgicos beta/genética , Receptores Adrenérgicos beta 3 , Estereoisomerismo , Transfección , TritioRESUMEN
A selection of novel 2-hydroxy-3-nitro-1,4-naphthoquinones are shown to be potent inhibitors of rat passive cutaneous anaphylaxis (PCA) and to have highest potency with alkyl substitution at both C-6 and C-7. The most potent compounds were 7c and 7e which produced a 50% inhibition in the rat PCA test at doses of about 10 micrometerM/kg following subcutaneous administration and showed activity after oral administration. Related 4-hydroxy-3-nitro-2(1H)-naphthalenones had no effect on rat PCA in doses up to 500 micrometerM/kg.
Asunto(s)
Naftoquinonas/síntesis química , Anafilaxis Cutánea Pasiva/efectos de los fármacos , Animales , Depresión Química , Masculino , Naftoquinonas/farmacología , Ratas , Relación Estructura-ActividadRESUMEN
A number of 2-cyanoindan-1,3-diones and 3-cyano-4-hydroxycoumarins have been prepared and assessed for potential antiallergy activity as measured by their ability to inhibit passive cutaneous anaphylaxis in the rat, mediated by rat serum containing antigen specific IgE. The structural requirements for activity were similar not only for both series of compounds but also for the analogous 2-nitroindan-1,3-diones and 4-hydroxy-3-nitrocoumarins previously reported. The most active compounds were 2-cyano-5,6-diethylindan-1,3-dione (4e) and 3-cyano-6,7-diethyl-4-hydroxycoumarin (11h).
Asunto(s)
4-Hidroxicumarinas/síntesis química , Hipersensibilidad/tratamiento farmacológico , Indanos/síntesis química , Indenos/síntesis química , 4-Hidroxicumarinas/farmacología , Animales , Cromolin Sódico/farmacología , Inmunoglobulina E , Indanos/farmacología , Ovalbúmina/inmunología , Anafilaxis Cutánea Pasiva/efectos de los fármacos , Ratas , Relación Estructura-ActividadRESUMEN
The synthesis and biological activity of a number of 4-hydroxy-3-nitro-2-quinolones are discussed and compared with their related hydroaromatic analogs. Antiallergic activity has been assessed by their ability to inhibit the homocytotropic antibody-antigen induced passive cutaneous anaphylaxis reaction in the rat.
Asunto(s)
Hidroxiquinolinas/síntesis química , Hipersensibilidad/tratamiento farmacológico , Nitroquinolinas/síntesis química , Animales , Hidroxiquinolinas/uso terapéutico , Masculino , Nitroquinolinas/uso terapéutico , Anafilaxis Cutánea Pasiva , Ratas , Pruebas CutáneasRESUMEN
Selected omega-nitroacetophenones, formed by the alcoholic cleavage of 2-nitroindandiones, have been shown to inhibit the homocytotropic antibody-antigen induced passive cutaneous analhylaxis reaction in the rat. The enzymatic cyclization of these derivatives to the parent nitroindandione has been demonstrated both in vivo and in vitro and this process is suggested as a possible prerequisite to biological activity.
Asunto(s)
Acetofenonas/síntesis química , Hipersensibilidad/tratamiento farmacológico , Acetofenonas/sangre , Acetofenonas/uso terapéutico , Animales , Ciclización , Técnicas In Vitro , Hígado/metabolismo , Nitrocompuestos/sangre , Nitrocompuestos/síntesis química , Nitrocompuestos/uso terapéutico , Anafilaxis Cutánea Pasiva , Ratas , Espectrofotometría UltravioletaRESUMEN
Twenty-four substituted 4-hydroxy-3-nitrocoumarins have been prepared for nitration of the corresponding 4-hydroxycoumarins. All were found to possess antiallergic activity as measured by the homocytotropic antibody-antigen induced passive cutaneous anaphylaxis reaction in the rat.