1. Institute of Pharmacy, Christian-Albrechts-University of Kiel, Gutenbergstraße 76, D-24116 Kiel, Germany
2. GEOMAR Centre for Marine Biotechnology (GEOMAR-Biotech), Research Unit of Marine Natural Products Chemistry, GEOMAR Helmholtz Centre for Ocean Research Kiel, Am Kiel-Kanal 44, 24106 Kiel, Germany