Triterpene Saponins from Eryngium campestre

Five new triterpene saponins, 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucuronopyranosyl-22-O-β,β-dimethylacryloyl-A1-barrigenol (1), 3-O-α-L-rhamnopyranosyl-(l-2)-β-D-glucuronopyranosyl-22-O-angeloyl-Rl-barrigenol (2), 3-O-α-L-rhamnopyranosyl-( 1-2)-β-D-glucuronopyranosyl-21-O-acetyl-22-O-angeloyl-R1-barrigenol (3), 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucuronopyranosyl-21-O-acetyl-22-O-β,β-dimethylacryloyl-R 1-barrigenol (4), and 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucuronopyranosyl-22-O-angeloyl-28-O-acetyl-R1-barrigenol (5), were isolated from the roots of Eryngium campestre. Their structures were established mainly by 2D NMR techniques and mass spectrometry. Compounds 1-4 and 3-O-β-D-glucopyranosyl-(1→2)-[a-L-rhamnopyranosyl-(1→4)]-β-D-glucuronopyranosyl-22-O-β,β-dimethylacryl-oyl-Al-barrigenol, previously isolated from the same plant, showed a weak cytotoxicity when tested against HCT 116 and HT 29 human colon cancer cells.