Bioorganic model of isoprene formation from mevalonic acid in vitro

Jiří Gasparič¹ (gasparic@faf.cuni.cz), Karel Kolář², Šárka Crhová¹, Radomír Hyšpler³, Alena Tichá⁴, Lidmila Hyšplerová², Monika Indrová⁴, Karel Myška²

¹Department of Biophysics and Physical Chemistry, Charles University in Prague, Faculty of Pharmacy in Hradec Králové,
²Department of Chemistry, Faculty of Education, University of Hradec Králové, Hradec Králové,
³Department of Biochemistry, Charles University in Prague, Faculty of Medicine in Hradec Králové,
⁴Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Pardubice,
Czech Republic

Summary

The in vitro fission of D,L-mevalonic acid with 50 % sulphuric acid at 100 °C resulted in the formation of isoprene identified by gas chromatography — mass spectrometry. When the same reaction was performed with D,L-mevalonolactone-2-¹³C two types of isoprene isomers were distinguished in the mass spectra: isoprene with the ¹³C carbon atom in position 1 or in the methyl group, resp. These isomers were formed in the ratio 2:1. The experimental results were compared with selected quantum chemical calculations and were found to be in agreement with the common knowledge of dehydration reactions.