Quantitative analysis of ingenol in Euphorbia species via validated isotope dilution ultra-high performance liquid chromatography-tandem mass spectrometry

Béres T., Dragull K., Pospíšil J., Tarkowská D., Dančák M., Bíba O., Tarkowski P., Doležal K., Strnad M.
PHYTOCHEMICAL ANALYSIS : , 2017

Keywords: Ingenol; ultra-high performance liquid chromatography; mass spectrometry; isotope-dilution method; Euphorbia genus
Abstract: Introduction – Various species of the Euphorbia genus contain diterpene ingenol and ingenol mebutate (ingenol-3-angelate), a substance found in the sap of the plant Euphorbia peplus and an inducer of cell death. A gel formulation of the drug has been approved by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for the topical treatment of actinic keratosis. Objective – To develop a rapid and reliable method for quantification of ingenol in various plant extracts. Methodology – Methanolic extracts of 38 species of the Euphorbia genus were analysed via ultra-high performance liquid chromatography with tandem mass spectrometry after methanolysis and SPE purification. The 18O-labelled ingenol analogue was prepared and used as an internal standard for ingenol content determination and method validation. Results – The highest ingenol concentration (547 mg·kg-1 of dry weight) was found in the lower leafless stems of E. myrsinites. The screening confirms a substantial amount of ingenol in species studied previously and furthermore, reveals some new promising candidates. Conclusion – The newly established UHPLC-MS/MS method shows to be an appropriate tool for screening of the Euphorbia genus for ingenol content and allows selection of species suitable for raw material production and/or in vitro culture initiation.
DOI: 10.1002/pca.2711
Fulltext:
IEB authors: Karel Doležal, Jiří Pospíšil, Miroslav Strnad, Danuše Tarkowská