A spirostanol glycoside from wild yam (Diosccorea villosa) extract and its cytostatic activity on three cancer cells

A spirostanol glycoside, (25R)-spirost-5-en-3β-ol 3-O-α-L-rhamnopyranosyl -(1→2)-O-[β-D-glucopyranosyl -(1→4)]-β-D-glucopyranoside, was isolated from wild yam (Dioscorea villosa) extract with reversed-phase preparative HPLC. This was the first time found in yams (Dioscorea species). The structure was identified by LC-MS, ¹H- and ¹³C-NMR. Cytostatic activities of the isolated saponin on Hep G2, HEK293 and MCF7 cells were estimated. Growth of these cells was inhibited as higher concentration of the compound was used. The IC₅₀ values of the isolated spirostanol glycoside and its aglycon, diosgenin, were 9.02 and 23.91 μM for Hep G2 cells, 13.21 and 27.31 μM for HEK293 cells, and 16.74 and 35.38 μM for MCF7 cells, respectively. The isolated compound had significantly higher active intensity than diosgenin.