Triterpenoids from the leaves of Eleutherococcus sessiliflorus, and their antiproliferative activities in TNF-α induced HFLS-RA cells

Five undescribed elesesterpenes L-U, along with nine known 3,4-seco-lupane-type triterpenoids were isolated from the leaves of Eleutherococcus sessiliflorus (Rupr. & Maxim.) S. Y. Hu. Elesesterpene L-S, and U were lupane-type triterpenoids, whereas elesesterpene T was an oleanane-type triterpenoid, probably artifact, as suggested by LC-MS analysis. Out of the nine known compounds, five were initially identified in E. sessiliflorus. Moreover, their structures were definitively determined using spectroscopic analyses, and the absolute configurations of elesesterpenes L-M and sachunogenin 3-O-glucoside were clarified using X-ray crystallographic techniques. The absolute configuration of elesesterpene T was determined by measuring and calculating its ECD. In addition, all compounds were tested to examine their ability to inhibit the proliferation of HFLS-RA cells induced by TNF-α in vitro. Elesesterpene M, chiisanogenin, chiisanoside, and 3-methylisochiisanoside significantly inhibited HFLS-RA proliferation.