Inhibition of NO Production by Grindelia argentina and Isolation of Three New Cytotoxic Saponins |
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| Authors: | Natalia P Alza Eva‐Maria Pferschy‐Wenzig Sabine Ortmann Nadine Kretschmer Olaf Kunert Gerald N Rechberger Rudolf Bauer Ana P Murray |
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| Institution: | 1. INQUISUR‐CONICET, Departamento de Química, Universidad Nacional del Sur, Avenida Alem 1253, Bahía Blanca, 8000, Argentina (phone: +54‐291‐4595101 ext 3538;2. fax: +54‐291‐4595187);3. Institute of Pharmaceutical Sciences, Department of Pharmacognosy, University of Graz, Universit?tsplatz 4, AT‐8010 Graz;4. Institute of Pharmaceutical Sciences, Department of Pharmaceutical Chemistry, University of Graz, Universit?tsplatz 1, AT‐8010 Graz;5. Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/II, AT‐8010 Graz |
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| Abstract: | A bioassay‐guided phytochemical analysis of the ethanolic extract of Grindelia argentina Deble & Oliveira ‐Deble (Asteraceae) allowed the isolation of a known flavone, hispidulin, and three new oleanane‐type saponins, 3‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐O‐β‐D ‐xylopyranosyl‐(1→2)‐β‐D ‐apiofuranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→3)‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl ester ( 2 ), 3‐O‐β‐D ‐glucopyranosyl‐2β,3β,23‐trihydroxyolean‐12‐en‐28‐oic acid 28‐O‐β‐D ‐xylopyranosyl‐(1→2)‐β‐D ‐apiofuranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→3)‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl ester, ( 3 ) and 3‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐2β,3β,23‐trihydroxyolean‐12‐en‐28‐oic acid 28‐O‐β‐D ‐xylopyranosyl‐(1→2)‐β‐D ‐apiofuranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→3)‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl ester ( 4 ), named grindeliosides A–C, respectively. Their structures were determined by extensive 1D‐ and 2D‐NMR experiments along with mass spectrometry and chemical evidence. The isolated compounds were evaluated for their inhibitory activities against LPS/IFN‐γ‐induced NO production in RAW 264.7 macrophages and for their cytotoxic activities against the human leukemic cell line CCRF‐CEM and MRC‐5 lung fibroblasts. Hispidulin markedly reduced LPS/IFN‐γ‐induced NO production (IC50 51.4 μM ), while grindeliosides A–C were found to be cytotoxic, with grindelioside C being the most active against both CCRF‐CEM (IC50 4.2±0.1 μM ) and MRC‐5 (IC50 4.5±0.1 μM ) cell lines. |
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| Keywords: | Grindelia argentina Grindeliosides A – C Triterpene saponins Saponins Hispidulin Nitric oxide Cytotoxic activity |
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