1. Organic Chemistry; Department of Chemistry; Faculty of Sciences; University of Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Germany
2. Heinrich-Pette-Institute; Leibniz Institute of Experimental Virology; Martinistrasse 52 20251 Hamburg Germany
3. Laboratory of Virology and Chemotherapy, Department of Microbiology and Immunology; Rega Institute for Medical Research; KU Leuven; Minderbroedersstraat 10 3000 Leuven Belgium