1. R. Koljak, Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232–6602, USA, and Department of Bioorganic Chemistry, Institute of Chemistry, Tallinn, Estonia EE0026.
2. O. Boutaud, B.-H. Shieh, A. R. Brash, Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232–6602, USA.
3. N. Samel, Department of Bioorganic Chemistry, Institute of Chemistry, Tallinn, Estonia EE0026.