Planta Med 2009; 75 - PG32
DOI: 10.1055/s-0029-1234686

Study of decomposition behaviour of absinthin from Artemisia absinthium using LC/MS and LC-SPE-NMR

A Aberham 1, SS Cicek 1, P Schneider 1, H Stuppner 1
  • 1Institute of Pharmacy/Pharmacognosy*, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria, * Member of the Center for Molecular Biosciences (CMBI)

Artemisia absinthium L., commonly known as wormwood, is a well-known medicinal plant with monographs in several pharmacopoeas (e.g. Ph.Eur.). The aerial parts are used to treat anorexia and indigestion. Sesquiterpene lactones e.g. absinthin, a dimer guaianolide, and the monomer artabsin account for the bitter taste of this plant. Absinthin is also regarded as marker substance to confirm the authenticity of wormwood.

In weak acidic medium absinthin is unstable and isomerizes into anabsinthin [1]. Older literature describes absinthin as a glucoside, being decomposed by hydrolysis into sugar, a liquid and a resinous compound [2]. To determine the stability of the bitter substance, the degradation behaviour of absinthin was investigated under different stress conditions (hydrolytic, oxidative, photolytic and thermal). An aqueous ethanol solution of absinthin was found to be stable for up to 6 months (recovery rate by HPLC analysis ≥95%). This was also the case when the solid compound was kept in the refrigerator at -35°C. In contrast, the colourless needles, when stored in an exsiccator at 25°C and exposed to light, turned yellow. In total, 3 decomposition compounds were detected by LC/MS and LC-SPE-NMR, and identified as dimeric sesquiterpene lactones. The major degradation product was anabsinthin, which is not only formed in acidic medium, but also under acid-free conditions [1].

Acknowledgemenst: This work was financially supported by Bionorica research GmbH, 6020 Innsbruck, Austria

References: [1] Hänsel, R. and Sticher, O. (2007) Pharmakognosie – Phytopharmazie, 8. Auflage, Springer Verlag, Heidelberg.

[2] Senger, O. (1892)J. Chem. Soc. 62:1240–1241.