1. Institute of Organic Chemistry, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
2. Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Department of Microbial Natural Products, Helmholtz Centre for Infection Research (HZI) and Department of Pharmaceutical Biotechnology, Universität des Saarlandes, Campus E8.1, 66123 Saarbrücken, Germany
3. German Centre for Infection Research (DZIF), Partner Site Hannover−Braunschweig, 38124 Braunschweig, Germany
4. Kekulé Institute of Organic Chemistry and Biochemistry, University of Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany