PARP Inhibitor XI, DR2313 is a water soluble and brain-permeable pyrimidinone compound that functions as a Poly(ADP-ribose) polymerase inhibitor. Poly(ADP-ribose) polymerases, known as PARP, function by triggering DNA repair mechanisms and activating apoptosis in damaged cells. Studies show that DR2313 is a NAD+ utilizing enzyme which competitively inhibits Poly(ADP-ribose) polymerases but does not display selectivity among PARP-1 and PARP-2. In addition, in vitro studies of cerebral ischemia exhibiting an overactivation of PARP can be reduced by introducing DR2313