1. Department of Pharmaceutical Analysis and Nuclear Pharmacy, Faculty of Pharmacy, Comenius University, Odbojarov 10, SK-832 32 Bratislava, Slovak Republic, Laboratory of Pharmacognosy and Phytochemistry, Faculty of Pharmaceutical Sciences, University of Gent, Harelbekestraat 72, B-9000 Gent, Belgium, and Laboratory of Food Analysis, Faculty of Pharmaceutical Sciences, University of Gent, Harelbekestraat 72, B-9000 Gent, Belgium