Quantitative analysis of phytoestrogens in kudzu-root, soy and spiked serum samples by high-pressure liquid chromatography

Biomed Chromatogr. 2004 Jul;18(6):367-80. doi: 10.1002/bmc.326.


A sensitive and reliable HPLC method that allows simultaneous quantification of phytoestrogens extracted from kudzu-root and soy preparations, and serum samples has been developed. Kudzu-root and soy preparations were mixed with 5 microg flavone and 15 microg rutin (internal standards) and the phytoestrogens were extracted by using solid-phase (C18) extraction cartridges. Blank or spiked serum samples were extracted by using either C18 cartridges or trichloroacetic acid-methanol extraction. The extracts were analyzed by the HPLC equipped with a reverse-phase (250 x 4 mm, C18) column and UV, diode-array or MS detector. A linear gradient of acetic acid and acetonitrile provided excellent separation of glycoside and aglycone-phytoestrogens from kudzu root and soy preparations. The C18 cartridge extraction of serum yielded excellent recovery of both glycoside- and aglycone-phytoestrogens, while the trichloroacetic acid-methanol extraction yielded excellent recovery of glycoside but poor recovery of aglycone compounds. UV and MS detectors were suitable for phytoestrogen analysis in plant and serum samples, while the diode-array detector was suitable for generating the UV absorbance curve for phytoestrogens.

Publication types

  • Validation Study

MeSH terms

  • Chromatography, High Pressure Liquid / methods*
  • Glycine max / chemistry*
  • Mass Spectrometry / methods
  • Phytoestrogens / analysis*
  • Phytoestrogens / blood
  • Phytoestrogens / chemistry
  • Plant Roots / chemistry*
  • Pueraria / chemistry*
  • Quantitative Structure-Activity Relationship
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Spectrophotometry, Ultraviolet / methods


  • Phytoestrogens