Cytotoxic effect of triterpenoids from the root bark of Hibiscus syriacus.

In this study, 4 new triterpenoids-3β- acetoxy-olean-11-en,28,13β-olide (1), 3β- acetoxy-11α,12α-epoxy-olean-28,13β-olide (2), 19α-epi-betulin (3), and 20, 28-epoxy-17β,19β-lupan-3β-ol (4)-and 12 known compounds, were isolated from the root bark of Hibiscus syriacus L. by using acetone extraction. Their structures were characterized by extensive spectroscopic analysis. To investigate cytotoxicity, A549 human lung cancer cells were exposed to the extract and the compounds identified from it. Significantly reduced cell viability was observed with betulin-3-caffeate (12) (IC50, 4.3 μM). The results of this study indicate that betulin-3-caffeate (12) identified from H. syriacus L. may warrant further investigation for potential as anticancer therapies.