1. Department of Pharmaceutical Biology, Institute of Pharmacy, Faculty of Mathematics and Natural Sciences, Ernst-Moritz-Arndt-University of Greifswald, Jahnstrasse 15a, D-17487 Greifswald, Germany, Institute of Chemistry, Faculty of Mathematics and Natural Sciences, Humboldt-University of Berlin, Hessische Strasse 1-2, D-10115 Berlin, Germany, and Institute of Automation, Faculty of Engineering, University of Rostock, Richard-Wagner-Strasse 31/H.8, D-18119 Rostock-Warnemünde, Germany