1. Department of Basic Pharmaceutical Sciences, West Virginia University, 1 Medical Center Drive, P.O. Box 9530, Morgantown, WV 26506, USA
2. Memorial Sloan Kettering Cancer Center, Molecular Pharmacology & Chemistry Program, 1275 York Avenue, New York, NY 10065, USA
3. Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA