Aspidiata E, a New Spirostanol Saponin From Aspidistra triradiata and its Cytotoxic Activity

Aspidiata E (1), a new spirostanol saponin {(22S*,25R*)-1 beta,3 beta,4 beta,5 beta,6 beta-pentahydroxyspirostan-2 beta-yl beta-D-xylopyranoside), together with 2 known compounds, (22S*,25R*)-spirost-5-ene-3 beta-yl O-alpha-L-rhamnopyranosyl-(1 -> 2)-O-[O-alpha-L-rhamnopyranosyl-(1 -> 5)-alpha-L-arabinofuranosyl-(1 -> 4)]-beta-D-glucopyranoside (2), and (22S*)-16-[(beta-D-glucopyranosyl)oxy]-1 beta,3 beta,22-trihydroxycholest-5-en-1 beta-yl alpha-L-rhamnopyranoside (3), were isolated from Aspidistra triradiata. Their structures were determined by NMR spectroscopic and high resolution electrospray ionisation mass spectrometry analysis and by comparison with published data. Compound 2 revealed strong cytotoxic potential against MCF7, HepG2, SK-LU-1, and HT-29 cancer cell lines with IC50 values ranging from 0.28 to 0.81 mu M. In contrast, compound 1 showed a weak inhibitory effect on MCF7, HepG2, and HT-29 cell lines, with IC50 values within the range of 68.85 to 84.19 mu M. All compounds 1-3 were discovered for the first time in the genus Aspidistra.