1. Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, Colorado 80523, United States, Life Sciences Institute and Department of Medicinal Chemistry, The University of Michigan, 210 Washtenaw Avenue, Ann Arbor, Michigan 48109-2216, United States, and Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto, 862-0973, Japan