1. PharmaCenter Bonn, Pharmaceutical
Institute, Pharmaceutical Chemistry I, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
2. Institute of Pharmaceutical and Medicinal Chemistry, University of Münster, Hittorfstrasse 58-62,
D-48149 Münster, Germany
3. CH-8592 Uttwil, Oberdorfstrasse 14, Switzerland