1. Department of Botany, Faculty of Sciences Palacky University Olomouc 783 71 Czech Republic
2. Department of Biochemistry, Faculty of Sciences Palacky University Olomouc 783 71 Czech Republic
3. Department of Analytical Chemistry, Faculty of Sciences Palacky University Olomouc 771 46 Czech Republic
4. Department of Bioorganic Chemistry Leibniz‐Institut für Pflanzenbiochemie Halle (Saale) 06120 Germany
5. Department of Biochemistry St Petersburg State University St Petersburg 199004 Russia
6. Department of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy Martin‐Luther University Halle‐Wittenberg 06120 Germany
7. Agricultural Research Ltd Troubsko 664 41 Czech Republic