RESUMO
Following the discovery of 4-(substituted amino)-1-alkyl-pyrazolo[3,4-b]pyridine-5-carboxamides as potent and selective phosphodiesterase 4B inhibitors, [Hamblin, J. N.; Angell, T.; Ballentine, S., et al. Bioorg. Med. Chem. Lett.2008, 18, 4237] the SAR of the 5-position was investigated further. A range of substituted heterocycles showed good potencies against PDE4. Optimisation using X-ray crystallography and computational modelling led to the discovery of 16, with sub-nM inhibition of LPS-induced TNF-α production from isolated human peripheral blood mononuclear cells.
Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/química , Compostos Heterocíclicos/química , Inibidores de Fosfodiesterase/química , Pirazóis/química , Piridinas/química , Sítios de Ligação , Simulação por Computador , Cristalografia por Raios X , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Humanos , Modelos Químicos , Modelos Moleculares , Inibidores de Fosfodiesterase/síntese química , Inibidores de Fosfodiesterase/farmacologia , Estrutura Terciária de Proteína , Pirazóis/síntese química , Pirazóis/farmacologia , Piridinas/síntese química , Piridinas/farmacologia , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Optimisation of a high-throughput screening hit resulted in the discovery of 4-(substituted amino)-1-alkyl-pyrazolo[3,4-b]pyridine-5-carboxamides as potent and selective inhibitors of Phosphodiesterase 4 (PDE4). Herein, we describe early SAR studies around this novel template highlighting preferred substituents and rationalization of SAR through X-ray crystal structures of analogues bound to the PDE4 active site. Pyrazolopyridine 20a was found to be a potent and selective PDE4 inhibitor which also inhibits LPS induced TNF-alpha production from isolated human peripheral blood mononuclear cells and has an encouraging rat PK profile suitable for oral dosing.
