1. Department of Organic Chemistry; Faculty of Science; Charles University in Prague; Hlavova 2030/8 12843 Prague 2 Czech Republic
2. Department of Biochemistry; Faculty of Science; Charles University in Prague; Hlavova 2030/8 12843 Prague 2 Czech Republic
3. Department of Pharmacology and Toxicology; School of Pharmacy; University of Kansas; Lawrence KS 66045 USA