Abstract
Three new oleanane-type saponins, giganteosides L (1), M (2) and N (3) along with eight known ones were isolated from the roots of Cephalaria gigantea. Their structures were established as 3-O-[β-D-galactopyranosyl-(1→2)-β-D-glucuronopyranosyl]-28-O-[β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl]-oleanolic acid, 3-O-[β-D-galactopyranosyl-(1→2)-β-D-glucuronopyranosyl]-28-O-[β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl]-hederagenin, 3-O-[α-L-rhamnopyranosyl-(1→2)-β-D-glucuronopyranosyl]-28-O-[β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl]-hederagenin, respectively, by means of spectroscopic methods (1D and 2D NMR, HR-ESI-MS). Cytotoxic activity of monodesmosides was investigated in vitro using three cancer cell lines, namely, human non pigmented melanoma MEL-5 and human leukemia HL-60. Giganteosides D (4) and E (5) showed antiproliferative effect on human cell lines with IC50 values in the range 3.15—7.5 μM.
