1. Department of Chemistry, University of Turku, FIN-20014 Turku, Finland, Department of Clinical Chemistry, Tampere University Hospital and University of Tampere, P. O. Box 2000, FIN-33521 Tampere, Finland, Department of Organic Chemistry, Åbo Akademi University, FIN-20500 Turku, Finland, and Department of Pharmacology and Clinical Pharmacology, Institute of Biomedicine, University of Turku, FIN-20520 Turku, Finland, and Helsinki University Hospital (Jorvi Hospital), FIN-02740 Espoo, Finland