Two novel saponins of 20, 26-epoxy derivatives of pseudojujubogenin from the seeds of Hovenia trichocarpa.

Two new saponins of 20, 26-epoxy derivatives of pseudojujubogenin, hoduloside XI (1) and hoduloside XII (2) were isolated from the seeds of Hovenia trichocarpa. The structures of the new compounds were established by extensive NMR experiments and chemical methods. Hoduloside XI was confirmed to be 3-O-{ß-D-glucopyranosyl(1→3)-[ß-D-xylopyranosyl(1→2)]-α-L-arabinopyranosyl}-20, 26-epoxypseudojujubogenin. Hoduloside XII was identified as 3-O-{ß-D-xylopyranose(1→2)glucopyranosyl(1→3)[rhamnopyranose(1→2)]ß-D-glucopyranosyl}-20, 26-epoxypseudojujubogenin. The in vitro cytotoxic activity of compounds 1 and 2 was assayed. They displayed inhibitive activities against human cancer cell lines HL60 and K562.