1. Department of Pharmacology, Department of Chemistry, and Vanderbilt Institute of Chemical Biology, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232, United States
2. PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53121 Bonn, Germany
3. Technical Research and Development, Novartis, via Ribes 5, Colleretto Giacosa 10010, Italy