1. Institute of Biochemistry, Biological Research Center of the Hungarian Academy of Sciences, 6701 Szeged, P.O. Box 521, Hungary; Department of Inorganic and Analytical Chemistry, University of Debrecen, 4010 Debrecen, P.O. Box 21, Hungary; Department of Inorganic and Analytical Chemistry, University of Szeged, 6701 Szeged, P.O. Box 440, Hungary; Department of Organic Chemistry, Vrije University Brussels, Pleinlaan 2, 1050 Brussels, Belgium; and Department of Pharmacology and Pharmacotherapy, Faculty of...