Synthesis and evaluation of tricyclic derivatives containing a non-aromatic amide as inhibitors of poly(ADP-ribose)polymerase-1 (PARP-1).

Highly potent poly(ADP-ribose)polymerase-1 (PARP-1) inhibitors, including 9-hydroxy-1,2-dihydro-4H-thiopyrano[3,4-c]quinolin-5(6H)-one derivatives with a non-aromatic A-ring, were synthesized. Among the derivatives, 12a showed low nanomolar enzyme and cellular activity (IC(50) = 42 nM, ED(50) = 220 nM) with good water solubility. Further, 12a exhibited microsomal stability in vitro and brain permeability in vivo.