1. Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, Praha 6 16610, Czech Republic
2. Department of Organic Chemistry, Faculty of Science, Charles University, Albertov 6, Praha 2 12800, Czech Republic
3. Department of Chemistry, Stanford University, Stanford, California 94305, United States
4. Department of Pathology, School of Medicine, Stanford University, Stanford, California 94305, United States
5. Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského n. 2, Praha 6 16206, Czech Republic