RESUMO
The peptide hormone ghrelin is the endogenous ligand for the type 1a growth hormone secretagogue receptor (GHS-R1a) and the only currently known circulating appetite stimulant. GHS-R1a antagonism has therefore been proposed as a potential approach for obesity treatment. More recently, ghrelin has been recognized to also play a role in controlling glucose-induced insulin secretion, which suggests another possible benefit for a GHS-R1a antagonist, namely, the role as an insulin secretagogue with potential value for diabetes treatment. In our laboratories, piperidine-substituted quinazolinone derivatives were identified as a new class of small-molecule GHS-R1a antagonists. Starting from an agonist with poor oral bioavailability, optimization led to potent, selective, and orally bioavailable antagonists. In vivo efficacy evaluation of selected compounds revealed suppression of food intake and body weight reduction as well as glucose-lowering effects mediated by glucose-dependent insulin secretion.
Assuntos
Diabetes Mellitus/tratamento farmacológico , Obesidade/tratamento farmacológico , Quinazolinonas/síntese química , Receptores de Grelina/antagonistas & inibidores , Administração Oral , Animais , Ligação Competitiva , Glicemia/análise , Linhagem Celular , Ingestão de Alimentos/efeitos dos fármacos , Teste de Tolerância a Glucose , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Quinazolinonas/química , Quinazolinonas/farmacologia , Ensaio Radioligante , Ratos , Ratos Wistar , Estereoisomerismo , Relação Estrutura-Atividade , Redução de Peso/efeitos dos fármacosRESUMO
Activation of the NPY2 receptor to reduce appetite while avoiding stimulation of the NPY1 and NPY5 receptors that induce feeding provides a pharmaceutical approach to modulate food intake. The naturally occurring peptide PYY(3-36) is a nonselective NPY1, NPY2, and NPY5 agonist. N-terminal truncation of PYY to abrogate affinity for the NPY1 and NPY5 receptors and subsequent N-terminal modification with aminobenzoic analogs to restore NPY2 receptor potency results in a series of highly selective NPY2 receptor peptide agonists.
Assuntos
Ingestão de Alimentos/efeitos dos fármacos , Peptídeo YY/química , Peptídeo YY/farmacologia , Receptores de Neuropeptídeo Y/agonistas , Ligação Competitiva/efeitos dos fármacos , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Guanosina 5'-O-(3-Tiotrifosfato)/farmacologia , Humanos , Indicadores e Reagentes , Fragmentos de Peptídeos , Receptores de Neuropeptídeo Y/efeitos dos fármacosRESUMO
We have developed a highly convergent synthesis of the manumycin-type m-C7N-antibiotic nisamycin that is applicable to other members of this family of antibiotics. The synthesis features a three-step sequence to the epoxyquinol core that serves as a scaffold for the attachment of the polyene side chains. The eastern polyene side chain was constructed via a novel organozirconocene-mediated synthesis. Zirconocene methodology was also applied to the synthesis of the polyene side chains of asukamycin. The southern side chain of nisamycin was introduced via a Stille reaction that employed a vinyl bromo ketone, derived from an acid-sensitive bromo ketal. Pd-mediated coupling of the vinyl bromide with a stannyl TIPS ester gave TIPS-protected nisamycin that was readily converted to the natural product.