AUTHOR=Wang Huijuan , Ma Guoxu , Wang Huaxiang , Li Lingyu , Dong Aijun , Liu Huiping , Huo Xiaoshuang , Si Jianyong , Wang Junchi 

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

JOURNAL=Frontiers in Chemistry

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.885487

DOI=10.3389/fchem.2022.885487

ISSN=2296-2646

ABSTRACT=<p>Four novel triterpenoid alkaloids, siragrosvenins A–D (<bold>1–4</bold>), and two new cucurbitane-type triterpenoids, siragrosvenins E–F (<bold>5</bold>, <bold>6</bold>), together with eight known analogs (<bold>7−14</bold>), were isolated from the roots of <italic>Siraitia grosvenorii</italic>. Compounds <bold>1−4</bold> possessed a rare cucurbitane-type triterpenoid scaffold, featuring an extra pyrazine unit <italic>via</italic> the Strecker reaction in the cucurbitane framework. Compound <bold>5</bold> 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<sup>+</sup> analysis method was applied for the first time to determine the absolute configurations of the trihydroxybutyl moiety in the side chain of compounds <bold>1–4</bold>. <italic>In vitro</italic> cytotoxicity screening found that compounds <bold>4, 8, 9, 13,</bold> and <bold>14</bold> exhibited remarkable cytotoxic activities against three cell lines with IC<sub>50</sub> 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 <italic>via</italic> the induction of G2/M phase arrest and significantly induced apoptosis in MCF-7 cells.</p>