Novel Triterpenoid Alkaloids With Their Potential Cytotoxic Activity From the Roots of Siraitia grosvenorii

Abstract

Four novel triterpenoid alkaloids, siragrosvenins A–D (1–4), and two new cucurbitane-type triterpenoids, siragrosvenins E–F (5, 6), together with eight known analogs (7−14), were isolated from the roots of Siraitia grosvenorii. Compounds 1−4 possessed a rare cucurbitane-type triterpenoid scaffold, featuring an extra pyrazine unit via the Strecker reaction in the cucurbitane framework. Compound 5 displayed a 6/6/6/5/6/5-fused polycyclic ring system, with an uncommon fused furan and pyran ring in the side chain. All the structures were characterized by extensive spectroscopic analysis, including HRESIMS, NMR, and X-ray crystallographic data. It is worth noting that the DP4+ analysis method was applied for the first time to determine the absolute configurations of the trihydroxybutyl moiety in the side chain of compounds 1–4. In vitro cytotoxicity screening found that compounds 4, 8, 9, 13, and 14 exhibited remarkable cytotoxic activities against three cell lines with IC50 values ranging from 1.44 to 9.99 μM. Siragrosvenin D shows remarkable cytotoxic activity on MCF-7 cells. As a result, it inhibited the proliferation of MCF-7 cells and reduced their viability via the induction of G2/M phase arrest and significantly induced apoptosis in MCF-7 cells.

The generally useful estimate of solvent systems method facilitates off‐line two‐dimensional countercurrent chromatography for isolating compositions from Siraitia grosvenorii roots

“…A key issue in the research on herbal medicine involves the clarification of the pharmacodynamic material basis. A few chemical investigations of the ethanolic extract of the roots have reported the isolation of some cucurbitacin compounds, including siraitic acids A-F and two cucurbitane-type glycosides [3][4][5][6][7][8]. These compounds are usually separated through multidimensional solid-based column chromatography, an extremely time-consuming process.…”