1. Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences; Flemingovo nám. 2 166 10 Prague 6 Czech Republic
2. Fachbereich Chemie; Technische Universität Braunschweig; Hagenring 30 38106 Braunschweig Germany
3. Department of Inorganic Chemistry; Faculty of Science; Charles University; Hlavova 2030/8 128 43 Prague 2 Czech Republic
4. Gilead Sciences, Inc.; 333 Lakeside Drive 94404 Foster City CA USA