RESUMEN
The identification of novel, non-purine based inhibitors of xanthine oxidase is described. After a high-throughput screening campaign, an NMR based counterscreen was used to distinguish actives, which interact with XO in a reversible manner, from assay artefacts. This approach identified pyrimidone 1 as a reversible and competitive inhibitor with good lead-like properties. A hit to lead campaign gave compound 41, a nanomolar inhibitor of hXO with efficacy in the hyperuricemic rat model after oral dosing.
Asunto(s)
Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Pirimidinonas/química , Pirimidinonas/farmacología , Xantina Oxidasa/antagonistas & inhibidores , Animales , Sitios de Unión , Evaluación Preclínica de Medicamentos , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/farmacocinética , Inhibidores Enzimáticos/uso terapéutico , Supresores de la Gota/química , Supresores de la Gota/farmacocinética , Supresores de la Gota/farmacología , Supresores de la Gota/uso terapéutico , Semivida , Ensayos Analíticos de Alto Rendimiento , Hiperuricemia/tratamiento farmacológico , Espectroscopía de Resonancia Magnética , Simulación del Acoplamiento Molecular , Unión Proteica , Estructura Terciaria de Proteína , Pirimidinonas/farmacocinética , Pirimidinonas/uso terapéutico , Ratas , Relación Estructura-Actividad , Xantina Oxidasa/metabolismoRESUMEN
We describe the discovery of novel inhibitors of prostaglandin D2 synthase (PGDS) through fragment-based lead generation and structure-based drug design. A library of 2500 low-molecular-weight compounds was screened using 2D nuclear magnetic resonance (NMR), leading to the identification of 24 primary hits. Structure determination of protein-ligand complexes with the hits enabled a hit optimization process, whereby we harvested increasingly more potent inhibitors out of our corporate compound collection. Two iterative cycles were carried out, comprising NMR screening, molecular modeling, X-ray crystallography, and in vitro biochemical testing. Six novel high-resolution PGDS complex structures were determined, and 300 hit analogues were tested. This rational drug design procedure culminated in the discovery of 24 compounds with an IC 50 below 1 microM in the in vitro assay. The best inhibitor (IC 50 = 21 nM) is one of the most potent inhibitors of PGDS to date. As such, it may enable new functional in vivo studies of PGDS and the prostaglandin metabolism pathway.