1. Laboratory of Medicinal Chemistry and Laboratory of Medical Biochemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium, Erasmus MC, Josephine Nefkens Institute, Department of Medical Oncology, Dr. Molewaterplein 50, 3015 GE Rotterdam, Netherlands, and Wilex AG, Grillparzestr. 10, 81675 Munich, Germany