Studies On The Quality Control Standard Of Desmodium Styracifolium (Osbeck) Merr.

Snowbell-leaf tickclover is a Chinese medicinal herb, which widely has beeen used for curing urination disturbance caused by damp-heat, urolithiasis accompanied by difficult and painful urination, edema with oliguria, and jaundice with dark urine. It facilitates diuresis and relieves dysuria. In the Chinese Pharmacopoeia (2000), Snowbell-leaf tickclover herb is described as the dried aerial part of Desmodium styracifolium (Osbeck) Merr. of the family Leguminosae. This species is widely distributed in the southeast China. The effective chemical compounds are flavonoids and saponins according to past researches on the chemical constituents and pharmacological experiments of Desmodium styracifolium.Snowbell-leaf tickclover lacks an overall standard to control its quality in practice up to now. Described in the Chinese Pharmacopoeia (2000) there are only morphological characteristics, identification and the water-soluble extractives. In order to make a good use of the source of this medicine, we studied its quality control standard. We firstly established a standard method to determine not only the total flavonoids and saponins, but also its representative components based on the specificconstituents from references. Then, we determined the contents of water, total ash, acid-insoluble ash, water-soluble extractive, lead and arsenic. The results provide a scientific basis for quality control of the original materials and products of Desmodium styracifolium in the future. Our main research results are as follows:1. Using vicenin-2, the highest constituent in the total flavonoides, as a standard a column chromatography-UV spectrophotomatry was developed to determine total flavonoids in Desmodium styracifolium for the first time. This method is simple, accurate and reproducible. The content of total flavonoids of 11 batches from different sources varied from 1.34% to 2.59%.2. ARP-HPLC method was established for the determination of vicenin-2 in Desmodium styracifolium. This method is accurate and reproducible, which can be used in practice to control the quality of Desmodium styracifolium. The vicenin-2 of 11 batches from different sources varied from 0.106% to 0.452%, making up 7.91%-17.45% of the total flavonoids.3. Using soyasapogenol B, the specific constituent in Desmodium styracifolium, as a standard a spectrophotometric method was established to determine the total saponins in Desmodium styracifolium with AccuBondII SPE ODS-Cig Cartridges Pretreatment for the first time. The method is simple, accurate and reproducible. The total saponins of 11batches from different sources varied from 0.05704% to 0.12341%.4. A RP-HPLC method was established for the determination of the soyasapogenol B in Desmodium styracifolium. The content of soyasapogenol B of 11 batches from different sources varied from 0.00506% to 0.01940%, making up 6.37%-15.72% of the total saponins.5. We for the first times determined the contents of water, total ash, acid-insoluble ash, water-soluble extractive, lead and arsenic comprehensively. The content of water in 11 batches from different sources was different, which varied from the highest content, 12%, to the lowest, 7%. The content of water-soluble extractive was in accord with the demands of the Chinese Pharmacopoeia. The contents of total ash and acid-insoluble ash were different. The highest content for the former was 15% and for the latter, 8%. The content of lead in 10 batches was not more than 30ppm/g, while it was found to be more than 40ppm/g in only 1 batch. However, the content of arsenic in all 11 batches was samiliar, being not more than 2ppm/g.