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DOI: 10.1055/s-0028-1084435
New results on the phytochemistry and pharmacology of Doronicum austriacum Jaqc
Positive preliminary results showing an acetylcholinesterase (AChE) inhibitory activity of the dichloromethane extract of the roots of Doronicum austriacum Jaqc. (39.1±7.1% inhibition; c=1.0mg/ml; in vitro enzyme test based on Ellman's method [1]) incited a phytochemical reinvestigation [2], which led to the isolation and structure elucidation of three known dihydrobenzofurane derivatives: 6,12-dihydroxytremeton-12-O-isobutyrate, 6,12-dihydroxytremeton-12-O-(2-methyl)butyrate and 6,12-dihydroxytremeton. The activity was clearly related to the two prominent ester derivatives (50% mass of the investigated extract) with IC50 values >500µM. Investigations of the methanolic extract yielded two unknown tremeton derivates and three new diterpene acid derivatives: 12-O-ß-D-glucopyranosyl-6,12-dihydroxytremeton, 12-O-ß-D-[6-(3-hydroxy-3-methyl-glutaryl)-glucopyranosyl]-6,12-dihydroxy-tremeton; 4-carboxy-2-O-β-D-[2-(3-isopropyl-malat-1-methyl-ester)-glucopyranosyl]-atractyligenin, 4-carboxy-2-O-β-D-[2-(3-isopropyl-malat-1-methyl-ester)-isorhamnosyl]-atractyligenin and 2-O-β-D-[2-(3-isopropyl-malat-1-methyl-ester)-glucopyranosyl]-atractyligenin. Since Doronicum extracts and sub-fractions are described to possess cytostatic effects on isolated mice fibroblasts [3] all isolated compounds were tested for their cytotoxic potential at two different cell-types (HUVEC and CCRF-CEM-C7H2). The used concentrations (c=10 and 100µM) showed no significant change in the percentage of viable, necrotic or apoptotic cells when analyzed by FACS after 24h in comparison to control and might not be involved in the described effect.
Acknowledgements: This work was supported by the Austrian Science Fund (P18379).
References: 1. Ellman, GL. et al. (1961) Biochem Pharmacol 7: 88–95.
2. Bohlmann, F. et al. (1970) Tetrahedron Lett 41: 3575–6.
3. Petričić, J. et al. (1991) Acta Pharm Jugosl 41: 169–73.