1. Department of Chemistry, University of Iowa, Iowa City, Iowa 52242-1294, United States
2. Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269-3092,United States
3. Department of Chemistry, Western Michigan University, Kalamazoo, Michigan 49008-5413, United States
4. Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut 06269-3092, United States
5. Department of Pharmacology, University of Iowa, Iowa City, Iowa 52242-1109, United States