Objective:To investigate extraction rate variation of harpagide in different separated recipes of Simiao Yong'an decoction

and explore its regularity of compatibility. Method: Extraction rate of harpagide from 8 separated recipes of Simiao Yong'an decoction was determined by HPLC

using a SunFireTM C18 column (4.6 mm×150 mm

5 μm)

acetonitrile-water containing 0.1% H3PO4 in gradient elution as mobile phase

the detection wavelength was set at 250 nm

the flow rate was 1.0 mL·min-1

column temperature of 35 ℃

then extraction rate variation of harpagide was analyzed. Result: The regression equation of harpagide was Y=1.22×106X+3 218.75(r=0.999 8) with the liner range of 0.065 3-0.457 μg

the average recovery was 96.81% with RSD of 1.83%. Extraction rate of harpagide from different separated recipes was in order of the original prescription>Scrophularia ningpoensis>other separated recipes. Conclusion: All these seven separated recipes of Simiao Yong'an decoction reduced extraction rate of harpagide

which showed a distinct advantage of the original prescription.And harpagide may be one of effective components in Simiao Yong'an decoction.