RESUMO
The high expression of MCH in the hypothalamus with the lean hypophagic phenotype coupled with increased resting metabolic rate and resistance to high fat diet-induced obesity of MCH KO mice has spurred considerable efforts to develop small molecule MCHR1 antagonists. Starting from a lead thienopyrimidinone series, structure-activity studies at the 3- and 6-positions of the thienopyrimidinone core afforded potent and selective MCHR1 antagonists with representative examples having suitable pharmacokinetic properties. Based on structure-activity relationships, a structural model for MCHR1 was constructed to explain the binding mode of these antagonists. In general, a good correlation was observed between pKas and activity in the right-hand side of the template, with Asp123 playing an important role in the enhancement of binding affinity. A representative example when evaluated chronically in diet-induced obese mice resulted in good weight loss effects. These antagonists provide a viable lead series in the discovery of new therapies for the treatment of obesity.
Assuntos
Fármacos Antiobesidade/síntese química , Pirimidinas/síntese química , Receptores de Somatostatina/antagonistas & inibidores , Tiofenos/síntese química , Administração Oral , Animais , Fármacos Antiobesidade/química , Fármacos Antiobesidade/farmacologia , Disponibilidade Biológica , Células CHO , Cricetinae , Cricetulus , Canal de Potássio ERG1 , Canais de Potássio Éter-A-Go-Go/efeitos dos fármacos , Canais de Potássio Éter-A-Go-Go/fisiologia , Genes Reporter , Meia-Vida , Humanos , Camundongos , Camundongos Obesos , Modelos Moleculares , Pirimidinas/química , Pirimidinas/farmacologia , Ratos , Relação Estrutura-Atividade , Tiofenos/química , Tiofenos/farmacologiaRESUMO
Genetic manipulation studies in mice at both the MCH receptor 1 (MCHR1) as well as the MCH peptide levels have implicated MCHR1 as a key player in energy homeostasis. The phenotype exhibited by these studies, that is, increased metabolic rate, resistance to high fat diet, and subsequent weight loss, has spurred considerable efforts to develop antagonists of MCHR1. In continuation of efforts directed toward this goal, the present work capitalizes on the putative binding mode of an MCH antagonist, resulting in the identification of several novel chemotypes that are potent and selective MCHR1 antagonists. In addition, the favorable pharmacokinetics of representative examples has allowed for the evaluation of an MCHR1 antagonist in a high fat diet-induced obese rodent model of obesity. The tolerability of the right-hand side of the template for diverse chemotypes accompanied by favorable effects on weight loss enhances the attractiveness of this template in the pursuit toward development of effective anti-obesity agents.