1. Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, and The Purdue Cancer Center, Purdue University, West Lafayette, Indiana 47907
2. Ikosatec GmbH, Königsbergerstr. 74, 85748 Garching, Germany
3. Institute of Food Chemistry, University of Hamburg, D-20146 Hamburg, Germany
4. Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66047