1. a Department of Analytical Chemistry , Faculty of Chemical Engineering, Institute of Chemical Technology , Technická 5, 166 28, Prague 6 , Czech Republic
2. b First Faculty of Medicine, Charles University in Prague , Katerinská 32, 121 08, Prague 2 , Czech Republic
3. c Institute of Molecular Genetics, Academy of Sciences of the Czech Republic , Vídenská 1083, 142 20, Prague 4 , Czech Republic
4. d Zentiva R&D, part of Sanofi-Aventis , U Kabelovny 130, 102 37, Prague 10 , Czech Republic