RESUMEN
An effort aimed at exploring structural diversity in the N-pyrazole-N'-naphthylurea class of p38 kinase inhibitors led to the synthesis and characterization of N-phenyl-N'-naphthylureas. Examples of these compounds displayed excellent inhibition of TNF-alpha production in vitro, as well as efficacy in a mouse model of lipopolysaccharide induced endotoxemia. In addition, perspective is provided on the role of a sulfonamide functionality in defining inhibitor potency.
Asunto(s)
2-Naftilamina/análogos & derivados , Inhibidores de Proteínas Quinasas/farmacología , Urea/análogos & derivados , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , 2-Naftilamina/química , Animales , Química Orgánica/métodos , Química Farmacéutica/métodos , Cristalografía por Rayos X/métodos , Diseño de Fármacos , Concentración 50 Inhibidora , Lipopolisacáridos/metabolismo , Ratones , Modelos Químicos , Estructura Molecular , Factor de Necrosis Tumoral alfa/metabolismo , Urea/químicaRESUMEN
We report on the structure-activity relationships (SAR) of 1-(5-tert-butyl-2-p-tolyl-2H-pyrazol-3-yl)-3-[4-(2-morpholin-4-yl-ethoxy)naphthalen-1-yl]urea (BIRB 796), an inhibitor of p38alpha MAP kinase which has advanced into human clinical trials for the treatment of autoimmune diseases. Thermal denaturation was used to establish molecular binding affinities for this class of p38alpha inhibitors. The tert-butyl group remains a critical binding element by occupying a lipophilic domain in the kinase which is exposed upon rearrangement of the activation loop. An aromatic ring attached to N-2 of the pyrazole nucleus provides important pi-CH(2) interactions with the kinase. The role of groups attached through an ethoxy group to the 4-position of the naphthalene and directed into the ATP-binding domain is elucidated. Pharmacophores with good hydrogen bonding potential, such as morpholine, pyridine, and imidazole, shift the melting temperature of p38alpha by 16-17 degrees C translating into K(d) values of 50-100 pM. Finally, we describe several compounds that potently inhibit TNF-alpha production when dosed orally in mice.