Cytotoxic cardenolides and sesquiterpenoids from the fruits of Reevesia formosana

Bioassay-guided fractionation of the fruits of Reevesia formosana led to isolation of three cardenolides (reevesioside J, reevesioside K, and epi-reevesioside K), three sesquiterpenoids (reevesiterpenol C, reevesiterpenol D, and reevesiterpenol E), and two glycosides (reevesianin A and reevesianin B), along with 46 known compounds. Their structures were determined using spectroscopic techniques. In addition to the reported cytotoxic cardenolides, reevesioside J and strophanthidin exhibited moderate cytotoxicity against the cell lines MCF-7, NCI-H460, and HepG2, with IC50 values of 0.39 +/- 0.06 mu M and 1.06 +/- 0.12 mu M for MCF-7, 0.12 +/- 0.01 mu M and 0.29 +/- 0.01 mu M for NCI-H460, and 1.09 +/- 0.02 mu M and 1.72 +/- 0.02 mu M for HepG2, respectively. Reevesiterpenol E also exhibited the best selective cytotoxicity to the NCI-H460 cell line; with an IC50 value of 3.15 +/- 0.22 mu M. (C) 2016 Elsevier Ltd. All rights reserved.