1. Institute for Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic Resonance (BMRZ)Johann Wolfgang Goethe-Universität Frankfurt Max-von-Laue-Str. 7 60438 Frankfurt Germany
2. Institute for Molecular BiosciencesCenter for Biomolecular Magnetic Resonance (BMRZ)Johann Wolfgang Goethe-Universität Frankfurt Max-von-Laue-Str. 9 60438 Frankfurt Germany