1‐Acetyl‐3‐[(3R)‐hydroxyfatty acyl]glycerols: Lipid Compounds from Euphrasia rostkoviana Hayne and E. tetraquetra (Bréb.) Arrond. |
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Authors: | Peter Lorenz Diana N. Knittel Jürgen Conrad Eva M. Lotter Jörg Heilmann Florian C. Stintzing Dietmar R. Kammerer |
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Affiliation: | 1. +4971649307099+4971649307080;2. Department of Analytical Development & Research, Section 3. Phytochemical Research, WALA Heilmittel GmbH, Bad Boll/Eckw?lden;4. Institute of Chemistry, Bioorganic Chemistry, Hohenheim University, Stuttgart;5. Pharmaceutical Biology Department, University of Regensburg, Regensburg |
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Abstract: | Five homologous acetylated acylglycerols of 3‐hydroxyfatty acids (chain lengths C(14) – C(18)), named euphrasianins A – E, were characterized for the first time in Euphrasia rostkoviana Hayne (Orobanchaceae) by gas chromatography/mass spectrometry (GC/MS) and high‐performance liquid chromatography/atmospheric pressure chemical ionization‐mass spectrometry (HPLC/APCI‐MSn). In addition to mass spectrometric data, structures of euphrasianins were verified via a three‐step total synthesis of one representative homologue (euphrasianin A). The structure of the latter was confirmed by 1D‐ and 2D‐NMR experiments as well as high‐resolution electrospray ionization‐mass spectrometry (HR‐ESI‐MS). The absolute configuration of the 3‐hydroxyfatty acid moiety at C(3) was found to be R in the natural euphrasianins, which was determined by alkaline hydrolysis and methylation of a purified fraction, followed by chiral GC analysis. Furthermore, in extracts of Euphrasia tetraquetra (Bréb .) Arrond . euphrasianins C and E were detected exclusively, indicating that this subclass of lipid constituents is possibly valuable for fingerprinting methods. |
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Keywords: | Eyebright Orobanchaceae Acetyl monoacylglycerols Hydroxyfatty acids Euphrasianins |
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