1. Chemistry Department, Drug Discovery Division, Southern Research, 2000 Ninth Avenue South, Birmingham, Alabama 35205, United States
2. Department of Medicine, Division of Hematology and Oncology, University of Alabama at Birmingham, NP 2540 J, 1720 Second Avenue South, Birmingham, Alabama 35294-3300, United States
3. Department of Chemistry and Biochemistry, The University of Alabama, 250 Hackberry Lane, Tuscaloosa, Alabama 35487-0336, United States