1. Institute of Pharmaceutical and Medicinal Chemistry, Westphalian Wilhelms-University, Hittorfstrasse 58-62, D-48149 Münster, Germany, Leibniz Institute for Age Research—Fritz Lipmann Institute (FLI), Beutenbergstrasse 11, D-07745 Jena, Germany, ÆternaZentaris GmbH, Weismüllerstrasse 50, D-60314 Frankfurt, Germany