RESUMO
We previously reported potent BACE1 inhibitors KMI-420 and KMI-570 possessing a hydroxymethylcarbonyl isostere as a substrate transition-state mimic. Acidic moieties at the P(1)(') and P(4) positions of KMI inhibitors are thought to be unfavorable in terms of membrane permeability across the blood-brain barrier. Herein, we replaced acidic moieties at the P(4) position with hydrogen bond accepting groups and acidic moieties at the P(1)(') position with less acidic and similar molecular-size moieties (carboxylic acid or tetrazole bioisosteres). These inhibitors exhibited improved BACE1 inhibitory activities and a thorough quantitative structure-activity relationship study was performed.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Desenho de Fármacos , Inibidores Enzimáticos , Oligopeptídeos/síntese química , Oligopeptídeos/farmacologia , Ácidos Carboxílicos/química , Cristalografia por Raios X , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Modelos Moleculares , Estrutura Molecular , Oligopeptídeos/química , Tiazóis/química , Triazóis/químicaRESUMO
Recently, we reported potent and small-sized beta-secretase (BACE1) inhibitors KMI-570 and KMI-684 in which we replaced carboxylic acid groups at the P(1)(') position of KMI-420 and KMI-429, respectively, with tetrazole derivatives as carboxylic acid bioisosteres. These modifications improved significantly BACE1 inhibitory activity and chemical stability. In this study, the acidic tetrazole ring of the P(4) position of KMI-420 and KMI-570, respectively, was replaced with various hydrogen bond acceptor groups. We found BACE1 inhibitor KMI-574 that exhibited potent inhibitory activity in cultured cells as well as in vitro enzymatic assay.
Assuntos
Endopeptidases/química , Inibidores de Proteases/farmacologia , Secretases da Proteína Precursora do Amiloide , Ácido Aspártico Endopeptidases , Ácidos Carboxílicos/química , Células Cultivadas , Química Farmacêutica , Desenho de Fármacos , Ésteres/química , Humanos , Modelos Químicos , Modelos Moleculares , Inibidores de Proteases/química , Tetrazóis/químicaRESUMO
Recently, we reported potent and small-sized beta-secretase (BACE1) inhibitors KMI-420 and KMI-429 in which we replaced the Glu residue at the P4 position of KMI-260 and KMI-360, respectively, with a 1H-tetrazole-5-carbonyl DAP (L-alpha,beta-diaminopropionic acid) residue. At the P1' position, these compounds contain one or two carboxylic acid groups, which are unfavorable for crossing the blood-brain barrier. Herein, we report BACE1 inhibitors with P1' carboxylic acid bioisosteres in order to develop practical anti-Alzheimer's disease drugs. Among them, tetrazole ring-containing compounds, KMI-570 (IC50=4.8 nM) and KMI-684 (IC50=1.2 nM), exhibited significantly potent BACE1 inhibitory activities.
