1. Institute of PharmacyUniversity of Greifswald Friedrich-Ludwig-Jahn-Strasse 17 17489 Greifswald Germany
2. Institute of Pharmaceutical SciencesUniversity of Freiburg Albertstrasse 25 79104 Freiburg Germany
3. Institute of BiochemistryUniversity of Greifswald Felix-Hausdorff-Strasse 4 17487 Greifswald Germany
4. Department of Pharmaceutical ChemistryPharmaceutical InstituteChristian Albrechts University of Kiel 24118 Kiel Germany