1. Molecular Biotechnology Institute of Molecular Biosciences Goethe University Frankfurt 60438 Frankfurt am Main Germany
2. Institute of Molecular Biosciences and Center for Biomolecular Magnetic Resonance (BMRZ) Goethe University Frankfurt 60438 Frankfurt am Main Germany
3. Department of Natural Products in Organismic Interactions Max-Planck-Institute for Terrestrial Microbiology 35043 Marburg Germany
4. Senckenberg Gesellschaft für Naturforschung 60325 Frankfurt am Main Germany