1. Institute of Biochemistry University of Freiburg 79104 Freiburg Germany
2. Magellan Biologics & Consulting 4200-135 Porto Portugal
3. Institute of Organic Chemistry University of Freiburg 79104 Freiburg Germany
4. Institute of Pharmazeutical Sciences University of Freiburg Germany
5. Department of Biochemistry and Biophysics University of Pennsylvania Philadelphia PA 19104 USA
6. Department of Pharmacy University of Naples 80131 Napoli Italy
7. Department of Biochemistry and Molecular Biology Tel Aviv University 69978 Tel Aviv Israel