1. Department of Life Sciences and Chemistry, Jacobs University Bremen, D-28719Bremen, Germany
2. Department of Chemistry, University College London, WC1E 6BT London, United Kingdom
3. IOM/CNR, Sezione di Cagliari, Cittadella Universitaria di Monserrato, 09042 Monserrato, Italy
4. Department of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, D-72076 Tübingen, Germany
5. German Center for Infection Research (DZIF) Partner Site, D-72076 Tübingen, Germany
6. Department of Physics, University of Cagliari, and CNR/IOM, Cittadella Universitaria di Monserrato, 09042 Monserrato, Italy