1. Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
2. Forschungsanstalt Agroscope Changins-Wädenswil ACW, Schloss 1, Postfach, 8820 Wädenswil, Switzerland
3. Department of Clinical Research (AMSM), MR-Center 1, University of Bern and Inselspital, CH-3010 Bern, Switzerland