1. Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, United States
2. Department of Pathology, University of Michigan, 1301 Catherine St., Ann Arbor, Michigan 48109, United States
3. Norris Comprehensive Cancer Center, University of Southern California, NOR 6314A, 1441 Eastlake Ave., Los Angeles, California 90089, United States
4. Department of Medicinal Chemistry, University of Minnesota, 2231 6th St. SE, Minneapolis, Minnesota 55455, United States