Studies And Application On The Effective Components Of Snowbell-leaf Tickclover And Rhubarb Root

Snowbell-leaf tickclover is the dried aerial part of Desmodiiim styracifolhim (Osbeck) Merr., of which the main chemical constituents are flavonoids, saponins , polysaccharides, alkaloids etc.. It is a widely used herb and is the main raw material of Shilintong Tablet written in the Chinese Pharmacopoeia, and has been 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 can also' facilitate diuresis and relieve dysuria. Up to now, there are only some indefinite reports on the effective components used to cure urolithiasis, and lacking methods to determine the chemical content of the raw herb and Shilintong Tablet. Furthermore, Shilintong Tablet is an extract tablet made with the traditional method of extraction by water and deposition by alcohol, so it has the defect of high dose shoud be taken and difficult to control the quality.Rhapotin is a kind of stilbenoids isolated from the Rheum genus of the Polygonaceae family. According to our preliminary pharmacological experiments, this compound can reduce the blood glucose of the diabetes mellitus rats. The stilbenoids have been broadly studied since 1940 when the resveratrol was isolated, which are widely present in many plants and have various physiologic activities such as anti-oxidation, anti-cancer, anti-blood stasis syndrome (cephalitis, atherosclerosis, chronicinflamation), activating macrophages, anti-platelet aggregation, anti-anaphylaxis, eliminating free radicals. Some Chinese companies have tried to develop it but' failed because of lacking purification technology and quality control standard.In order to solve the exiting problems and develop new medicine, we carried out a series of experimental researches accordance with the stipulations of requirements fornew medicine application. The main research methods and results are as follows:1. Isolation and identification of schaftoside and rapontin: It is extremely difficult to obtain a certain quantity of monomer from natural products because of their complexity and low-content. Here using the traditional column chromatography and repeated re-crystallization, combined with HPLC of preparation model, we isolated schaftoside from snowbell-leaf sickclover and rhapotin from rhubarb root. The purity of them was above 98% through spectrum identification with UV, IR, MS, NMR and HPLC, so they can be used as the chemical reference substances for content determination.2. Studies on the content determination and quality standard: After getting the chemical reference substances, we studied the content determination of schaftoside, total flavonoids and rhapontin in the intermediate production. At the same time, we determined the content of residual small organic molecules in macroporous adsorption resin, such as benzene, toluene, dimethylbenzene, cinnamene in the middle production; lead and arsenic in the total flavonoids. It is concluded that the content of total flavonoids is above 50%, that of schaftoside above 4.5% and rhapontin above 90% in the intermediate production, lead below lOppm and arsenic below 2ppm, all of which were in accordance with the requirements of new medicine.3. Studies on the intermediate-scale preparation technic of total flavonoids from snowbell-leaf tickclover and rhapotin from rhubarb root: On the basis of content determination, using the total flavonoids as the index, we applied the orthogonal experiment to study the optimal extraction technic and the best technic to isolate and purify the total flavonoids from snowbell-leaf tickclover. We also used the same method to study the optimal extraction technic and the best technic to isolate and purify rhapotin from rhubarb root. It is revealed that the content of total flavonoids'is above 50% and that of rhapotin above 90%.4. Studies on pharmacodynamics and the activity of eliminating free radicals: Using the SpinTrapping and ESR technique, we studied the total flavonoids and rhapontin's activity of eliminating free radicals, explored the prevention andtreatment effect on glycol-induced renal calculus in rats, the treatment effect on rat's bladder stones implanted from man's, diursis action, antiinflammation action, alleviating pain action and the function of rhapotin of antihyperglycemia. The results showed that the total flavonoids has good activity to clear out hydroxyl radicals and superoxside anion radicals; The total flavonoids has good potential in the treatment of urolithiasis. While rhapotin has excellent function of inhibiting elevation of blood glucose of KK rats and induced by alloxan.