Triterpene glucosides from the leaves of Aralia elata and their cytotoxic activities.

Three new triterpene glucosides, named congmuyenosides C-E (1-3, resp.), along with four known ones, were isolated from an EtOH extract of Aralia elata (Miq.) Seem. leaves. The structures of the new compounds were identified as 3-O-{β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→3)-[β-D-glucopyranosyl-(1→2)]-β-D-glucopyranosyl}caulophyllogenin (1), 3-O-{β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→3)-[β-D-glucopyranosyl-(1→2)]-β-D-glucopyranosyl}hederagenin 28-O-β-D-glucopyranosyl ester (2), 3-O-{β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→3)-[β-D-glucopyranosyl-(1→2)]-β-D-glucopyranosyl}echinocystic acid 28-O-β-D-glucopyranosyl ester (3) on the basis of spectral analyses, including MS, (1) H-NMR, (13) C-NMR, DEPT, HSQC, HMBC, NOESY, and HSQC-TOCSY experiments. All isolates obtained were evaluated for their cytotoxic activities against three human tumor cell lines (HepG2, SKOV3, and A549). Compound 3 showed significant cytotoxicity against A549 cell line (IC50 9.9±1.5 μM).