1. Biomolecular NMR Laboratory
2. Department of Organic Chemistry
3. University of Barcelona
4. 10-12 08028 Barcelona
5. Spain
6. Department of Physical Chemistry
7. Martí i Franquès
8. 1-11 08028-Barcelona
9. Mass Spectrometry Core Facility
10. Institute for Research in Biomedicine (IRB Barcelona)
11. Instituto de Ciencia de Materiales de Aragón
12. CSIC-Universidad de Zaragoza
13. 50009 Zaragoza
14. Department of Physics
15. University of Antwerp
16. B-2610 Wilrijk
17. Belgium