1. Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, DE-97074 Wuerzburg, Germany
2. Novartis Pharma AG, Lichtstrasse 35, CH-4056 Basel, Switzerland
3. Institute of Organic Chemistry, University of Wuerzburg, Am Hubland, DE-97074 Wuerzburg, Germany
4. Helmholtz Institute for RNA-based Infection Biology (HIRI), Josef-Schneider-Strasse 2/D15, DE-97080 Wuerzburg, Germany