Cissatriterpenoids D-L, nine undescribed polyhydroxylated oleanane triterpenoids from Cissampelos pareira var....

Nine undescribed polyhydroxylated oleanane triterpenoids (cissatriterpenoids D-L, 1-9) were isolated from the roots of Cissampelos pareira var. hirsuta. Their structures and absolute configurations were elucidated by extensive spectroscopic analysis (HR-ESI-MS, UV, IR, NMR), and compared with the spectral data reported in the literature. All the compounds were tested for their cytotoxicity against MGC-803 and B16F10 cell lines, and inhibitory activity against nitric oxide (NO) release in LPS-induced RAW 264.7 cells. Among the tested compounds, compound 3 demonstrated the most potent cytotoxicity against the B16F10 cell line, with an IC₅₀ value of 28.58 μM (etoposide, 23.51 μM). Moreover, it also exhibited the strongest inhibition of NO production in LPS-stimulated RAW 264.7 cells with an IC₅₀ value of 17.73 μM, and was equivalent to that of the control drug dexamethasone (17.95 μM, P > 0.05). Compared with etoposide (47.77 μM), compounds 3 and 4 showed more potent cytotoxicities against the MGC-803 cell line with IC₅₀ values of 42.21 μM and 38.28 μM, respectively. The preliminary study of structure-activity relationship indicated that esterification of 28-OH by tiglic acid may enhance the cytotoxic activity against two cell lines and NO inhibition effect in LPS-stimulated RAW 264.7 cells of polyhydroxylated oleanane triterpenoids. In contrast, benzoylation of 28-OH was found to increase the cytotoxic activity of those compounds against MGC-803 cell line. These results revealed the potential of polyhydroxylated oleanane triterpenoids as lead compounds for anti-tumor and anti-inflammatory applications.