contrasting sirtuin and PARP-1 inhibitory activities. We showed that modification on benzimidazoles may alter their selectivity toward sirtuin or PARP-1 enzymes. This offers an opportunity for further discovery and development of new promising sirtuininhibitors. Molecular docking studies were carried out to aid the rationalization of these observations. Preliminary antiproliferative studies of selected
Benzimidazole-4-carboxamide compounds (I) which can act as potent inhibitors of the DNA repair enzyme poly(ADP-ribose) polymerase or PARP enzyme (EC 2.4.2.30), and which thereby can provide useful therapeutic compounds for use in conjunction with DNA-damaging cytotoxic drugs or radiotherapy to potentiate the effects of the latter. In formula (I), R and R' may each be selected independently from hydrogen, alkyl, hydroxyalkyl (e.g. CH.sub.2 CH.sub.2 OH), acyl (e.g. acetyl or benzoyl) or an optionally substituted aryl (e.g. phenyl) or aralkyl (e.g. benzyl or carboxybenzyl) group. R is generally a substituted phenyl group in the most preferred compounds. The compounds may also be used in the form of pharmaceutically acceptable salts or pro-drugs. ##STR1##
Poly (ADP-ribose) polymerases (PARPs) play diverse roles in various cellular processes that involve DNA repair and programmed cell death. Amongst these polymerases is PARP-1 which is the key DNA damage-sensing enzyme that acts as an initiator for the DNA repair mechanism. Dihydroorotate dehydrogenase (DHODH) is an enzyme in the pyrimidine biosynthetic pathway which is an important target for anti-hyperproliferative and anti-inflammatory drug design. Since these enzymes share a common role in the DNA replication and repair mechanisms, it may be beneficial to target both PARP-1 and DHODH in attempts to design new anti-cancer agents.Benzimidazole derivatives have shown a wide variety of pharmacological activities including PARP and DHODH inhibition. We hereby report the design, synthesis and bioactivities of a series of benzimidazole derivatives as inhibitors of both the PARP-1 and DHODH enzymes. (C) 2015 Elsevier Ltd. All rights reserved.