Design and Synthesis of Poly(ADP-ribose) Polymerase Inhibitors: Impact of Adenosine Pocket-Binding Motif Appendage to the 3-Oxo-2,3-dihydrobenzofuran-7-carboxamide on Potency and Selectivity.
Velagapudi, U.K., Langelier, M.F., Delgado-Martin, C., Diolaiti, M.E., Bakker, S., Ashworth, A., Patel, B.A., Shao, X., Pascal, J.M., Talele, T.T.(2019) J Med Chem 62: 5330-5357
- PubMed: 31042381 
- DOI: https://doi.org/10.1021/acs.jmedchem.8b01709
- Primary Citation of Related Structures:  
6NRF, 6NRG, 6NRH, 6NRI, 6NRJ - PubMed Abstract: 
Poly(adenosine 5'-diphosphate-ribose) polymerase (PARP) inhibitors are a class of anticancer drugs that block the catalytic activity of PARP proteins. Optimization of our lead compound 1 (( Z)-2-benzylidene-3-oxo-2,3-dihydrobenzofuran-7-carboxamide; PARP-1 IC 50 = 434 nM) led to a tetrazolyl analogue (51, IC 50 = 35 nM) with improved inhibition. Isosteric replacement of the tetrazole ring with a carboxyl group (60, IC 50 = 68 nM) gave a promising new lead, which was subsequently optimized to obtain analogues with potent PARP-1 IC 50 values (4-197 nM). PARP enzyme profiling revealed that the majority of compounds are selective toward PARP-2 with IC 50 values comparable to clinical inhibitors. X-ray crystal structures of the key inhibitors bound to PARP-1 illustrated the mode of interaction with analogue appendages extending toward the PARP-1 adenosine-binding pocket. Compound 81, an isoform-selective PARP-1/-2 (IC 50 = 30 nM/2 nM) inhibitor, demonstrated selective cytotoxic effect toward breast cancer gene 1 ( BRCA1)-deficient cells compared to isogenic BRCA1-proficient cells.
Organizational Affiliation: 
Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences , St. John's University , Queens , New York 11439 , United States.