野山藥（Dioscorea villosa）萃取物中主要的Spirostanol Glycoside分離與其於三種癌細胞之生長抑制活性   全文下載

A Spirostanol Glycoside from Wild Yam (Dioscorea villosa) Extract and Its Cytostatic Activity on Three Cancer Cells

本實驗以製備型HPLC自野山藥（Dioscorea villosa）萃取物中分離出一個主要的spirostanol glycoside，經LC-MS，1H- and 13C-NMR鑑定得知其結構為 （25R）-spirost-5-en-3β-ol 3-O-α-L-rhamnopyranosyl -（1→2）-O-[β-D-glucopyranosyl-（1→4）]-β-D-glucopyranoside，此乃首度於山藥植物中發現的固醇類皂素。此化合物於抑制Hep G2、HEK293 和 MCF7癌細胞株生長的研究中發現，使用的劑量愈高愈能抑制癌細胞株之生長。此spirostanol glycoside與其配醣體（aglycon）-diosgenin對Hep G2細胞株的IC50分別為9.02和23.91 μM；對HEK293細胞株的IC50分別為13.21 和 27.31 μM；對MCF7細胞株的IC50分別為16.74 和 35.38 μM，表示此固醇類皂素較diosgenin對上述之三種癌細胞株，有較高的生長抑制活性。

A spirostanol glycoside, (25R)-spirost-5-en-3β-ol 3-O-α-L-rhamnopyranosyl -(1→2)-O-[β-D-glucopyranosyl-(1→4)]-β-Dglucopyranoside, 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.