Oleanane-type triterpene saponins from Aralia armata leaves and their cytotoxic activity
Two new, aramatosides A and B (1 and 2), together with seven known oleanane-type triterpene saponins (3–9) were isolated from the leaves of Aralia armata. Their structures were determined by combination of HR-ESI-MS, 1 D and 2 D NMR spectral data as well as comparison with the previous literature. Compounds 6–9 exhibited cytotoxic effects towards three human cancer cell lines (HT29, A2058, and A549) with IC50 values ranging from 2.01 ± 0.17 to 18.8 ± 1.17 µM. Especially, compound 7 (narcissiflorin) showed significant cytotoxic activity against HT29 and A549 cell lines with IC50 values of 2.02 ± 1.65 and 2.01 ± 0.17 µM, respectively, which are smaller than those of positive control irinotecan hydrochloride (IC50 values of 10.3 ± 1.32 and 9.89 ± 0.19 µM).
