1. Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis Zografou, Athens 15771, Greece, Leibniz Institute for Age Research, Fritz Lipmann Institute (FLI), Jena 07745, Germany, and CEA, Service D’Ingénierie Moléculaire des Protéines (SIMOPRO), Bat 152, CE-Saclay, Gif/Yvette Cedex 91191, France