1. Isotope Laboratory, Institute of Experimental Botany AS CR, Vídeňská 1083, 14220 Prague 4, Czech Republic
2. Department of Chemistry of Natural Compounds, Institute of Chemical Technology in Prague, Technická 5, 16628 Prague 6, Czech Republic
3. Institute of Entomology, Biology Centre AS CR, Branišovská 31, 37005, České Budějovice, Czech Republic
4. Institute of Organic Chemistry and Biochemistry AS CR, Flemingovo náměstí 2, 16610, Prague 6, Czech Republic