RESUMO
Potent and selective antagonists of the adenosine A2A receptor often contain a nitrogen-rich fused-ring heterocyclic core. Replacement of the core with an isomeric ring system has previously been shown to improve target affinity, selectivity, and in vivo activity. This paper describes the preparation, by a novel route, of A2A receptor antagonists containing the [1,2,4]triazolo[1,5-a]pyrazine nucleus, which is isomeric with the [1,2,4]triazolo[1,5-c]pyrimidine core of a series of known A2A antagonists with in vivo activity in animal models of Parkinson's disease.
Assuntos
Antagonistas do Receptor A2 de Adenosina , Pirazinas/síntese química , Animais , Encéfalo/ultraestrutura , Membrana Celular/química , Membrana Celular/metabolismo , Modelos Animais de Doenças , Doença de Parkinson/tratamento farmacológico , Pirazinas/farmacologia , Ensaio Radioligante , Ratos , Relação Estrutura-AtividadeRESUMO
Piperazine derivatives of 2-furanyl[1,2,4]triazolo[1,5-a][1,3,5]triazine have recently been shown to be potent and selective adenosine A(2a) receptor antagonists. We now demonstrate that potent and selective A(2a) receptor antagonists could still be obtained when the arylpiperazines are separated from the triazolotriazine core structure by an ethylenediamine spacer. Selected analogs bearing this triazolotriazine or the related triazolopyrimidine core structure have been found to be orally active in a mouse catalepsy model of Parkinson's disease.
