Triterpenoid saponins from Ardisia gigantifolia.

Four new triterpenoid saponins (1—4) were isolated from the rhizome of Ardisia gigantifolia STAPF. The structures of new saponins were established as 3β-o-α-L-rhamnopyranosyl-(1→3)-[β-D-xylopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranosyl-16α--hydroxy-13,28-epoxy-oleanane (1), 3β-o-α-L-rhamnopyranosy)-(1→3)-[β-D-xylopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranosyl-16a-hydroxy-13,28-epoxy-30-acetoxy-oleanane (2), 3β-o-α-L-rhamnopyranosyl-(1→3)-[β-D-glucopyranosyl-(1→4)-β-D-xylopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranosyl-16α-hydroxy-13,28-epoxy-oleanane (3) and 3β-o-α-L-rhamnopyranosyl-(1→3)-[β-D-xylopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-[β-D-6-O-acetylglucopranosyl-(1→2)]-α-L-arabinopyranosyl-16α-hydroxy-13,28-epoxy-oleanane (4) were isolated from Ardisia gigantifolia STAPF. Their structures were elucidated by means of 1 H- and 13 C-NMR spectroscopic studies, including 2D-NMR technique. The cytotoxic activities of saponins 1—4 are reported against three human cancer cell lines, namely, Hela human cervical carcinoma cells, EJ human bladder tumor cells, and BCG-823 human gastric carcinoma cells.