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

Abstract

Aspidiata E (1), a new spirostanol saponin {(22 S*,25 R*)-1 β,3 β,4 β,5 β,6 β-pentahydroxyspirostan-2 β-yl β-D-xylopyranoside), together with 2 known compounds, (22 S*,25 R*)-spirost-5-ene-3 β-yl O- α-L-rhamnopyranosyl-(1→2)- O-[ O- α-L-rhamnopyranosyl-(1→5)- α-L-arabinofuranosyl-(1→4)]- β-D-glucopyranoside (2), and (22 S*)-16-[( β-D -glucopyranosyl)oxy]-1 β,3 β,22-trihydroxycholest-5-en-1 β-yl α-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 µM. 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 µM. All compounds 1-3 were discovered for the first time in the genus Aspidistra.