Taraxastane-type triterpenoids from the medicinal and edible plant Cirsium setosum

Guided by TNF-α secretion inhibitory activity assay, four taraxastane-type triterpenoids, including two new ones, 22-oxo-20-taraxasten-3β, 30-diol ( 1 ) and 22α-hydroxy-20-taraxasten-30β, 30-triol ( 2 ), have been obtained from an active fraction of the petroleum ether-soluble extract of the the medicinal and edible plant Cirsium setosum. Their structures were elucidated by spectroscopic data and CD data analysis. In the TNF-α secretion inhibitory activity assay, compounds 1 and 2 were active with the IC₅₀ of 2.6 and 3.8 μmol·L^-1, respectively. In addition, compounds 1 and 2 showed moderately selective cytotoxicity against the human ovarian cancer (A2780) and colon cancer (HCT-8) cell lines.