1. Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, USA
2. Harvey Cushing Neuro-Oncology Laboratories, Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
3. Microbiology, Bioorganic & Macromolecular Chemistry, Faculté de Pharmacie, Université libre de Bruxelles (ULB), Boulevard du Triomphe, 1050 Brussels, Belgium
4. Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky 40536, USA
5. University of Kentucky Markey Cancer Center, University of Kentucky, Lexington, KY, 40536, USA