1. Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany
2. Chemistry of Natural Compounds Department, Pharmaceutical and Drug Industries Research Division, National Research Centre, El-Behoos St. 33, Dokki-Cairo 12622, Egypt
3. Labor Grün-Wollny, Anemonenstr. 5, D-69469 Weinheim, Germany
4. Institut für Angewandte Mikrobiologie, Justus-Liebig Universität Giessen, D-35392 Giessen, Germany
5. Oncotest GmbH, Am Flughafen 12-14, D-79108 Freiburg, Germany