1. Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, P. O. Box 513, 5600MB Eindhoven, The Netherlands
2. Department of Drug Science and Technology, University of Turin, via Giuria 9, 10125 Turin, Italy
3. Department of Chemistry, Biology and Biotechnology, University of Perugia, Via Elce di Sotto 8, 06123, Perugia, Italy