Abstract: Five oleanane-type triterpenoid saponins were isolated from the roots of Psammosilene tunicoides W.C.Wu et C.Y.Wu. Their structures were elucidated by spectral and chemical methods as 3-O-β-D-galactopyranosyl-(1→2)-β-D-glucuronopyranosyl-gypsogenin(1),3-O-β-D-galactopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucuronopyranosyl-gypsogenin(2),3-O-β-D-galactopyranosyl-(1→2)-β-D-glucuronopyranosyl-gypsogenin-28-O-β-D-xylopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→3)]-α-L-rhamnopyranosyl(1→2)-β-D-fucopyranoside (Lobatoside I,3),3-O-β-D-galactopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucuronopyranosylgypsogenin-28-O-β-D-xylopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→3)]-α-L-rhamnopyranosyl(1→2)-β-D-fucopyranoside (4),3-O-β-D-galactopyranosyl-(1→2)-β-D-glucuronopyranosyl-gypsogenin-28- O-β-D-xylopyranosyl-(1→4)-[β-D-6-O-acetylglucopyranosyl-(1→3)]-α-L-rhamnopyranosyl(1→2)-β-D-fucopyranoside(5).Among them, compound 5 was a new triterpenoid saponin.

Key words: Psammosilene tunicoides