1. Leibniz Institute for Natural Product Research and Infection Biology; Hans Knöll Institute; Adolf-Reichwein-Strasse 23 07745 Jena Germany
2. Pharmaceutical and Medicinal Chemistry; Institute of Pharmacy; Friedrich-Schiller-Universität Jena; Philosophenweg 14 07743 Jena Germany
3. Institute for Pharmaceutical Biology; Rheinische Friedrich-Wilhelms-Universität Bonn; Nussallee 6 53115 Bonn Germany