Saponins from the roots of Nylandtia spinosa

From the roots of Nylandtia spinosa, four new triterpene saponins, 3- O-beta- d-glucopyranosylpresenegenin 28- O-beta- d-galactopyranosyl-(1-->4)-alpha- l-arabinopyranosyl-(1-->3)]-beta- d-xylopyranosyl-(1-->4)-beta- d-apiofuranosyl-(1-->3)]-alpha- l-rhamnopyranosyl-(1-->2)-beta- d-fucopyranosyl ester ( 1), 3- O-beta- d-glucopyranosylpresenegenin 28- O-beta- d-galactopyranosyl-(1-->4)-alpha- l-arabinopyranosyl-(1-->3)]-beta- d-xylopyranosyl-(1-->4)-alpha- l-rhamnopyranosyl-(1-->2)-beta- d-fucopyranosyl ester ( 2), 3- O-beta- d-glucopyranosylpresenegenin 28- O-beta- d-apiofuranosyl-(1-->4)-beta- d-galactopyranosyl-(1-->2)]-beta- d-xylopyranosyl-(1-->4)-alpha- l-rhamnopyranosyl-(1-->2)-beta- d-fucopyranosyl ester ( 3), and 3- O-beta- d-glucopyranosylpresenegenin 28- O-beta- d-apiofuranosyl-(1-->3)-beta- d-xylopyranosyl-(1-->4)-alpha- l-rhamnopyranosyl-(1-->2)-beta- 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 (IC50 > 5 microg/mL).