Saponins from the roots of Nylandtia spinosa

From the roots of Nylandtia spinosa, four new triterpene saponins, 3-0-β-D-glucopyranosylpresenegenin 28-0-β-D-galactopyranosyl-(1→4)-[a-L-arabinopyranosyl-(1→3)]-β-D-xylopyranosyl-(1→4)-[β-D-apiofuranosyl-(1→3)]-a-L-rhamnopyranosyl-(1→2)-β-D-fucopyranosyl ester (1), 3-0-β-D-glucopyranosylpresenegenin 28-0-β-D-galactopyranosyl-(1-4)-[a-L-arabinopyranosyl-(1→3)]-β-D-xylopyranosyl-(1→4)-a-L-rhamnopyranosyl-(1→2)-β-D-fucopyranosyl ester (2), 3-O-β-D-glucopyranosylpresenegenin 28-O-β-D-apiofuranosyl-(1→4)-[β-D-galactopyranosyl-(1→2)]-β-D-xylopyranosyl-(l-4)-a-L-rhamnopyranosyl-(1→2)-β-D-fucopyranosyl ester (3), and 3-0-β-D-glucopyranosylpresenegenin 28-O-β - D-apiofuranosyl-(1→3)-β-D-xylopyranosyl-(1→4)-a-L-rhamnopyranosyl-(1→2)-β-D-fucopyranosyl ester (4), were isolated, together with the known tenuifolin. Their structures were established mainly by 2D NMR techniques and mass spectrometry. Compounds 1-4 were evaluated for cytotoxicity against HCT 116 and HT-29 human colon cancer cells, but were inactive (IC 50 > 5 μg/ mL ).