1. Department of Pharmaceutical Technology, Albert‐Ludwigs‐University, Hermann‐Herder‐Str. 9, D‐79104 Freiburg, Germany,
2. Cardiological Research Laboratory of the Charité, Humboldt‐University, Ziegelstr. 5‐9, D‐10117 Berlin, Germany,
3. Institute of Physiological Chemistry, Martin‐Luther‐University, Hollystr. 1, D‐06114 Halle, Germany