Simultaneous analysis of diosgenin and sarsasapogenin in Asparagus officinalis byproduct by thin-layer chromatography

Asparagus officinalis L. has several biological activities including antifungal, antiviral and antitumoral activities due to the steroidal saponins. Normally diosgenin and sarsasapogenin are analysed separately by thin-layer chromatography or high-performance liquid chromatography (HPLC-UV or HPLC-ELSD), which is time-consuming and expensive, so we need to find a rapid solution to this problem.

To develop a sensitive, rapid and validated TLC method for simultaneous detection and quantification of diosgenin and sarsasapogenin.

Samples were prepared by extraction of A. officinalis with 70% aqueous ethanol to get steroidal saponins, and then hydrolysed using 36  mL 2 m hydrochloric acid for 3  h. The hydrolysis product was extracted with chloroform, and then analysed by TLC, the results of which were verified by HPLC and HPLC-MS.

The retention factor (R(f)) of diosgenin and sarsasapogenin on TLC plate were 0.49 and 0.6, respectively. After calculation from the regression equation of the standard curve, the contents of diosgenin and sarsasapogenin in the A. officinalis extract were 0.27-0.46 and 0.11-0.32%, respectively.

The study showed that thin-layer chromatography can be applied for the determination of diosgenin and sarsasapogenin in the oldest tissue of A. officinalis, and also can be conducted for screening of sapogenin in other plant or extracts.