RESUMEN
The design, synthesis, and biological evaluation of potent inhibitors of poly(ADP-ribose) polymerase-1 (PARP-1) are reported. A novel series of 3,4-dihydro-2H-[1,4]diazepino[6,7,1-hi]indol-1-ones were designed using a combination of protein structure-based drug design, molecular modeling, and structure-activity relationships (SAR). These novel submicromolar inhibitors possess a tricyclic ring system conformationally restricting the benzamide in the preferred cis orientation. The compounds were designed to optimize space-filling and atomic interactions within the NAD+ binding site of PARP-1. Previously described and newly adapted methods were applied to syntheses of these tricyclic inhibitors. Various modifications were made to the diazepinoindolones at the 6- and 7-positions in order to study this region of the active site and optimize noncovalent interactions. The electron density of derivative 28 bound to chicken PARP-1 revealed that the oxime makes a tight hydrogen bond with the catalytic gamma-carboxylate of glutamic acid (Glu) 988 in accordance with our original designs and models. Most of the compounds have been evaluated for inhibition of human PARP-1. Selected inhibitors were also tested for the ability to potentiate the cytotoxic effect of the DNA-damaging agent Topotecan.
Asunto(s)
Antineoplásicos/síntesis química , Azepinas/síntesis química , Indoles/síntesis química , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Antineoplásicos/química , Antineoplásicos/farmacología , Azepinas/química , Azepinas/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cristalografía por Rayos X , Diseño de Fármacos , Resistencia a Antineoplásicos , Sinergismo Farmacológico , Humanos , Indoles/química , Indoles/farmacología , Modelos Moleculares , Relación Estructura-Actividad , Inhibidores de Topoisomerasa IRESUMEN
A series of novel compounds have been designed that are potent inhibitors of poly(ADP-ribose) polymerase-1 (PARP-1), and the activity and physical properties have been characterized. The new structural classes, 3,4,5,6-tetrahydro-1H-azepino[5,4,3-cd]indol-6-ones and 3,4-dihydropyrrolo[4,3,2-de]isoquinolin-5-(1H)-ones, have conformationally locked benzamide cores that specifically interact with the PARP-1 protein. The compounds have been evaluated with in vitro cellular assays that measure the ability of the PARP-1 inhibitors to enhance the effect of cytotoxic agents against cancer cell lines.