1. Institute of Biotechnology; RWTH Aachen University; Worringerweg 3 52074 Aachen Germany
2. Department of Chemistry; University of Graz; Heinrichstrasse 28 8010 Graz Austria
3. DSM Ahead R&D BV/DSM Innovative Synthesis, Post address: P.O. Box 1066; 6160 BB Geleen The Netherlands
4. DWI-Leibniz Institut für Interaktive Materialien; Forckenbeckstraße 50 52074 Aachen Germany