A novel aliphatic glycoside and a new lignan glycoside from <i>Siraitia grosvenorii</i> and their hepatoprotective activities

Five glycosides (<b>1</b>-<b>5</b>) containing one novel aliphatic glycoside Luohanguonoside G (<b>1</b>), one new lignan glycoside Luohanguonoside H (<b>2</b>) and three known ones (<b>3</b>-<b>5</b>) were isolated from the fresh fruit extract of <i>Siraitia grosvenorii</i> (<i>S. grosvenorii</i>). Structurally, according to various spectroscopic techniques analysis, the new compounds <b>1</b> and <b>2</b> were elucidated as a rare seven-carbon heptane glucose glycoside and a lignan glycoside, respectively. Among <b>1</b>-<b>5</b>, the lignan glycosides <b>3</b> and <b>4</b> have been reported in other plants but separated from <i>S. grosvenorii</i> for the first time. Additionally, a cytotoxicity and a hepatoprotective activity experiment were performed on compounds <b>1</b>-<b>5</b> to evaluate their preventing ability for liver disease. The results indicate that compound <b>5</b> exhibited significant hepatoprotective activities in comparison with bicyclol and compound <b>1</b>-<b>4</b> exhibited moderate activity for liver protection compared to model control group. This research firstly assessed the hepatic protection competence of the isolates from <i>S. grosvenorii in vitro</i>, providing evidence for the further investigation on the preventing potential of liver diseases of this plant.