RESUMO
A unified strategy was conceived and implemented to deliver conformationally constrained anilides based on their preferred cis-amide conformers. The imidazole/triazole mimicing amide bonds were designed, building upon an earlier discovery of a novel series of tricyclic lactams MK2 kinase inhibitors. This approach enabled rapid, modular synthesis of structurally novel analogs. The efficient SAR development led to the discovery of low molecular weight and potent MK2 non-ATP competitive inhibitors with good ligand efficiency, which led to improved permeability and oral exposure in rats.
Assuntos
Amidas/química , Azóis/farmacologia , Descoberta de Drogas , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Azóis/síntese química , Azóis/química , Relação Dose-Resposta a Droga , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Conformação Molecular , Permeabilidade/efeitos dos fármacos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Ratos , Relação Estrutura-AtividadeRESUMO
Conformation restriction of linear N-alkylanilide MK2 inhibitors to their E-conformer was developed. This strategy enabled rapid advance in identifying a series of potent non-ATP competitive inhibitors that exhibited cell based activity in anti-TNFα assay.
Assuntos
Anilidas/química , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Lactamas/química , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Trifosfato de Adenosina/química , Trifosfato de Adenosina/metabolismo , Anilidas/síntese química , Anilidas/metabolismo , Ligação Competitiva , Avaliação Pré-Clínica de Medicamentos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lactamas/síntese química , Lactamas/metabolismo , Ligação Proteica , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Facile synthesis of two new series of tetracyclic azepine and oxazocine analogs is described. These analogs were evaluated for their potential as MAPKAP-K2 (MK2) inhibitors and several were found to be potent at inhibiting MK2 with a non-ATP competitive binding mode.
Assuntos
Azepinas/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Oxazocinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Azepinas/síntese química , Azepinas/química , Humanos , Estrutura Molecular , Oxazocinas/síntese química , Oxazocinas/química , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
A three-step protocol for SAR development was introduced and applied to the SAR studies of the MK2 inhibitor program. Following this protocol, key conformational features and functional groups for improving MK2 inhibitor activity were quickly identified. Through this effort, the initial gap observed between in vitro binding activity and cellular activity in the lead identification stage was very much reduced. Compound 28 was identified with single digit binding activity (IC(50)=8 nM) and good cellular activity (EC(50)=310 nM). This provides further evidence that non-ATP-competitive binding MK2 inhibitors are feasible by targeting the outside ATP pocket.
Assuntos
Química Farmacêutica/métodos , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Trifosfato de Adenosina/química , Animais , Desenho de Fármacos , Humanos , Concentração Inibidora 50 , Camundongos , Modelos Químicos , Conformação Molecular , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
Melanotan-II (MT-II), a cyclic heptapeptide, is a potent, non-selective melanocortinergic agonist. When administered centrally or systemically, MT-II elicited a profound inhibitory effect on food intake in rodents, presumably via activation of melanocortin-4-receptor (MC4R). In this study, we sought to investigate whether penetration of MT-II and iodo-MT-II into brain parenchyma is required for the anorectic effect following intravenous (IV) administration. Firstly, both MT-II and iodo-MT-II were effective at suppressing appetite in rats following their IV administration. We next surveyed by in vitro autoradiographic studies the distribution of selective (125)I-MT-II binding sites in multiple brain regions including areas important for feeding regulation such as the hypothalamus and caudal brainstem. Upon IV administration of (125)I-MT-II, significant radioactivity could not be detected in various brain regions by autoradiography except for a group of circumventricular organs (CVOs), which are anatomically situated outside the blood-brain barrier (BBB). The most intensely labeled CVOs include the subfornical organ, median eminence, area postrema and choroid plexus, and accumulation of radioactivity at these sites can be blocked by co-injection of excess unlabeled MT-II. Direct measurement of MT-II in the brain and plasma by LC-MS-MS following IV injection confirmed that the degree of MT-II penetration into the brain is negligible. Furthermore, when given peripherally under conditions that suppressed food intake, MT-II did not result in a detectable induction of c-Fos-like immunoreactivity in brain regions where a significantly elevated c-Fos expression was observed following intracerebroventricular injection of this peptide. Our results indicate that MT-II has a very limited brain penetration capability, and its effect on feeding behavior following systemic administration may be mediated by either the brain regions in close proximity to the CVOs or sites outside of the BBB, including CVOs or other peripheral systems.
Assuntos
Anorexia/metabolismo , Encéfalo/metabolismo , Peptídeos Cíclicos/farmacologia , alfa-MSH/análogos & derivados , alfa-MSH/agonistas , alfa-MSH/farmacologia , Animais , Anorexia/induzido quimicamente , Autorradiografia/métodos , Sítios de Ligação , Encéfalo/anatomia & histologia , Encéfalo/efeitos dos fármacos , Química Encefálica/efeitos dos fármacos , Mapeamento Encefálico , Vias de Administração de Medicamentos , Ingestão de Alimentos/efeitos dos fármacos , Isótopos de Iodo/farmacocinética , Masculino , Peptídeo Sintases/farmacologia , Peptídeos Cíclicos/sangue , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual , alfa-MSH/sangueRESUMO
Neuromedin U (NMU) and neuromedin S (NMS) are structurally related neuropeptides that have been reported to modulate energy homeostasis. Pharmacological data have shown that NMU and NMS inhibit food intake when administered centrally and that NMU increases energy expenditure. Additionally, NMU-deficient mice develop obesity, whereas transgenic mice overexpressing NMU are lean and hypophagic. Two high-affinity NMU/NMS receptors, NMUR1 and NMUR2, have been identified. NMUR1 is predominantly expressed in the periphery, whereas NMUR2 is predominantly expressed in the brain, suggesting that the effects of centrally administered NMU and NMS are mediated by NMUR2. To evaluate the role of NMUR2 in the regulation of energy homeostasis, we characterized NMUR2-deficient (Nmur2(-/-)) mice. Nmur2(-/-) mice exhibited a modest resistance to diet-induced obesity that was at least in part due to reduced food intake. Acute central administration of NMU and NMS reduced food intake in wild-type but not in Nmur2(-/-) mice. The effects on activity and core temperature induced by centrally administered NMU were also absent in Nmur2(-/-) mice. Moreover, chronic central administration of NMU and NMS evoked significant reductions in body weight and sustained reductions in food intake in mice. In contrast, Nmur2(-/-) mice were largely resistant to these effects. Collectively, these data demonstrate that the anorectic and weight-reducing actions of centrally administered NMU and NMS are mediated predominantly by NMUR2, suggesting that NMUR2-selective agonists may be useful for the treatment of obesity.