Simultaneous Determination of Furostanol and Spirostanol Glycosides in Taiwanese Yam (Dioscorea spp.) Cultivars by High Performance Liquid Chromatography
DENG-JYE YANG, TING-JANG LU AND LUCY SUN HWANG*
Graduate Institute of Food Science and Technology, National Taiwan University, 1, Sec. 4, Roosevelt Rd., Da-an District, Taipei City 106, Taiwan (R.O.C.)
(Received: April 4, 2003; Accepted: June 3, 2003)
ABSTRACT
A high performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of the steroid saponins, furostanol and spirostanol glycosides in Taiwanese yam cultivars. C18 column kept at 45℃ was used as the stationary phase. The mobile phase was a binary solvent system consisting of methanol and deionized water (62/38, v/v) in the first 20 min and 71/29 (v/v) from 21 to 65 min at a flow rate of 1 mL/min. Both evaporative light scattering detector (ELSD) and UV (203 to 215 nm) were employed and compared for the detection of saponins. The detection limits for ELSD and 203 nm UV were 2~3.5 mg and 0.1~0.2 mg, respectively at signal-to-noise ratio of 10. The recoveries of furostanol and spirostanol glycosides in the range of 0.25~3 mg were all above 92%. The presence of steroid saponins in Taiwanese yams was also determined.
Key words: diosgenin, evaporative light scattering detector, furostanol glycoside, high performance liquid chromatography, saponins, spirostanol glycoside, yam (Dioscorea spp.)