Quantitative Analysis Of Saponins In Herba Medicines And Extracts

Puerariae Flos, the flowers of Pueraria lobata (Willd.) OHWI and P. thomsonii Benth., is an important herbal medicine used to ameliorate crapulence in China. The qualitative and quantitative methods of triterpenoid saponins in the raw materials and commercial extracts of Puerariae Flos were carried out. The main results were as follows.1. By means of solvent partition, column chromatography and preparative HPLC methods, three reference substances, including kakkasaponin I, soyasaponin I and kaikasaponin III were obtained as well as spectral data for their structural elucidation and physico-chemical properties which provided material basis for the development of the qualitative and quantitative analysis of the triterpenoid saponins in Puerariae Flos.2. TLC method was established, for the first time, for the qualitative assay for saponins of the raw materials and commercial extracts of Puerariae Flos. The result indicated that the spots of kakkasaponin I, soyasaponin I and kaikasaponin III were detected in both the flower of P. lobata and that of P. thomsonii. However, a characteristic spot was shown only in the TLC chromatogram of the flower of P. thomsonii, which may be the marker component for the TLC identification of both crude materials of Puerariae Flos.3. The determination of total saponins of the raw materials and commercial extracts of Puerariae Flos was established by UV-Vis spectrophotometry for the first time. Although the method is practical, the procedure of purifying samples is necessary.4. The simultaneous and quantitative determination of kakkasaponin I, soyasaponin I and kaikasaponin III of the raw materials and commercial extracts of Puerariae Flos was established by RP-HPLC method. Validation test indicated the good repeatability and accuracy of the quantitative method, which is adequate for the quantitative analysis of 3 saponin components in the samples. The results of quantitative determination showed that there was similarity in the variety of saponins, but a significant difference in their contents between flowers of Pueraria lobata and P. thomsonii. And the contents of saponins of commercial extracts of Puerariae Flos were lower than those of the crude materials. 5. The effects of the extractive solvents of ethanol and water in various proportion on the extractive efficacy of triterpenoid saponins were investigated using extract yield, contents of triterpenoid saponins and their availability as the review indexes.