Planta Med 2006; 72 - S_036
DOI: 10.1055/s-2006-949769

Different strategies for discriminator identification in a NMR based metabonomics matrix of the genus Leontopodium using LC-SPE-NMR, 1H-NMR-guided isolation and classical phytochemistry

S Schwaiger 1, C Seger 1, M Godejohann 2, E Humpfer 2, S Hehenberger 1, LH Tseng 2, EP Ellmerer 3, M Spraul 2, H Stuppner 1
  • 1Institut für Pharmazie/Pharmakognosie, Leopold-Franzens-Universität Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
  • 2Bruker-Biospin GmbH, Silberstreifen 4, 76287 Rheinstetten, Germany
  • 3Institut für Organische Chemie, Leopold-Franzens-Universität Innsbruck, Innrain 52a, 6020 Innsbruck, Austria

The secondary metabolite profile of Edelweiss (Leontopodium alpinum Cass.; Asteraceae), is highly complex – more than 50 analytes have been characterized until now [1–4]. Thus, the chemotaxonomical assessment of the genus Leontopodium comprising more than thirty mostly Asian species seems a major undertaking not subsumable with a single analytical technique. NMR based metabolic profiling can be envisioned as alternative analytical approach. This technique, combining 1H-NMR spectroscopy of extracts with multivariate statistical data interpretation, allows an unbiased selection of spectral regions responsible for sample discrimination. Profiling of CDCl3-extracts of the roots of twelve Leontopodium species resulted in clear species discriminations. The three species with the highest variation compared to L. alpinum, the European Edelweiss, were identified as L. souliei Beauverd, L. franchetii Beauverd and L. subulatum Beauverd. Due to varying amounts of available plant material and differences in the obtained extract matrices, identification of the discriminating metabolites was carried out by three different strategies: LC-SPE-NMR experiments for L. souliei, 1H-NMR guided isolation for L. franchetii and classic phytochemical techniques (e.g. silica gel CC, Sephadex LH 20 CC and preparative TLC) for L. subulatum. These three distinctly different strategies allowed in each case the identification and structure elucidation of the discriminating constituents. Differences of the applied methods in time consume, amount of the required plant material, yield of the discriminating compounds and costs will be discussed.

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