Cytotoxic triterpenoid saponins from Ardisia pusilla

A new triterpenoid saponin, 3-O-{β-d-xylopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 4)-[β-d-glucopyranosyl-(1 → 2)]-α-l-arabinopyranosyl}-3β,16α,28α-trihydroxy-13β,28-epoxy-oleanan-30-al (ardipusilloside III, 1), together with two known saponins, ardisiacrispins A (2) and B (3), were isolated from the whole plants of Ardisia pusilla A. DC. Their structures were elucidated by extensive spectral analysis and chemical evidences. Saponins 1 and 3 exhibited significant cytotoxicity against human glioblastoma U251MG cells.