Potent and Selective Double-Headed Thiophene-2-carboximidamide Inhibitors of Neuronal Nitric Oxide Synthase for the Treatment of Melanoma.
Huang, H., Li, H., Yang, S., Chreifi, G., Martasek, P., Roman, L.J., Meyskens, F.L., Poulos, T.L., Silverman, R.B.(2014) J Med Chem 57: 686-700
- PubMed: 24447275 
- DOI: https://doi.org/10.1021/jm401252e
- Primary Citation of Related Structures:  
4KCH, 4KCI, 4KCJ, 4KCK, 4KCL, 4KCM, 4KCN, 4KCO, 4KCP, 4KCQ, 4KCR, 4KCS - PubMed Abstract: 
Selective inhibitors of neuronal nitric oxide synthase (nNOS) are regarded as valuable and powerful agents with therapeutic potential for the treatment of chronic neurodegenerative pathologies and human melanoma. Here, we describe a novel hybrid strategy that combines the pharmacokinetically promising thiophene-2-carboximidamide fragment and structural features of our previously reported potent and selective aminopyridine inhibitors. Two inhibitors, 13 and 14, show low nanomolar inhibitory potency (Ki = 5 nM for nNOS) and good isoform selectivities (nNOS over eNOS [440- and 540-fold, respectively] and over iNOS [260- and 340-fold, respectively]). The crystal structures of these nNOS-inhibitor complexes reveal a new hot spot that explains the selectivity of 14 and why converting the secondary to tertiary amine leads to enhanced selectivity. More importantly, these compounds are the first highly potent and selective nNOS inhibitory agents that exhibit excellent in vitro efficacy in melanoma cell lines.
Organizational Affiliation: 
Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.