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 ( IC 50 9.9±1.5 μ M ).