6(5H)-Phenanthridinone

6(5H)-Phenanthridinone is a potent inhibitor of Poly(ADP-ribose) Polymerase (PARP) and displays immunosuppressive activity. It is a mixed-type inhibitor that acts on both the enzyme and enzyme-NAD+ complex at sites distinct from the NAD+-binding site to attenuate the fall in NAD and ATP, and consequently, improves cell survival.