[Determination of saponins in Dipsaci Radix by HILIC-HPLC]

To develop an HILIC-HPLC method for simultaneous analysis of three main active triterpenoid saponins including dipsacus asponin VI, dipsacus asponin X and dipsacus asponin XII. To evaluate the medical material from various habitats in China, different commercial grades or parts of plant.

The HPLC was conducted on Venusil HILIC column (4.6 mm x 250 mm, 5 microm) with acetonitrile and water as the mobile phase at 25 degrees C, which was in gradient elution. The flow rate was 1 mL x min(-1); and the detection wavelength was 203 nm.

The contents of dipsacus asponin VI, X and XII were 0.77%-14.31%, 0.39%-3.19% and 0.41%-1.49% respectively in different provinces of China, that were related to locations. The contents of saponins from Yunnan and Sichuan provinces were higer than those of Hubei and Guizhou. Thick roots, which were high-class products, contained less saponins than thin ones. In addition, the contents of stem, residual parts of stem and fibrous roots were fewer than main roots.

This method is simple, sensitive and accurate. It could be used to determine the contents of dipsacus asponin VI, X, XII and evaluate the quality of dipsacus asperoides.