Studies On Quality Standard Of Folium Steviae Rebaudianae

Folium Steviae Rebaudianae (Tianye Ju) is the dried leaf of Stevia rebaudianaBertoni. Lots of studies have suggested that Folium Steviae Rebaudianae may offertherapeutic benefits such as anti-hyperglycemic, anti-hypertensive, anti-inflammatory,anti-tumor, immunomodulatory and antioxidant actions. And dried stevia leaves havebeen used as natural sweeteners for many years. The Chinese pharmacopoeia (allversions) have not recorded this herb, yet lack of quality standard.Characteristic components from Folium Steviae Rebaudianae are searched tomake a distinguish between the original species and fake stamps. After consulting alot of references, we found that diterpenes were thought to be the main bioactivecompounds in the herb. The diterpene components Stevioside and Rebaudioside A arethe main anti-hypertensive and anti-hyperglycemic ingredients which have highcontents in the plant, so Stevioside and Rebaudioside A are used as referencestandards. By column chromatography, recrystallization, Stevioside and RebaudiosideA were puried. Their structures were identified by MS, UV, IR, NMR.According to the technical demands of quality standard of new drug, thesystematic research test of identification and content assay of Folium SteviaeRebaudianae was studied.(1) Microscopic and TLC identification methods for Folium Steviae Rebaudianaewere established. The results shows that24batches samples are real and the methodsare specific for identification of Folium Steviae Rebaudianae.(2) According the Chinese pharmacopoeia (Volume I,2010version), the contentof impurity, moisture and ash were determined. According to the examination resultsof24batches samples, the limits of impurity content, moisture content and ashcontent should be less than5%,13%and11%, respectively. The gas chromatograph was be used to determine the organochlorine pesticidesresidues (-BHC, β-BHC, γ-BHC,-BHC, p, p’-DDE, o, p’-DDT, p, p’-DDD, p,p’-DDT and PCNB). According to the result, the content of total BHC, DDT andPCNB should be less than210-7,210-7,110-7, respectively.(3) The alcohol-soluble extract was detected with hot dipping. Accroding to theresult, the limits of alcohol-soluble extract should not be less than41%.(4) The method of detecting Stevioside and Rebaudioside A in Folium SteviaeRebaudianae by HPLC-DAD is established. The results show that the method is rapid,sensitive and accurate, and it can be used for quality control of Folium SteviaeRebaudianae. According to the experimental result, it is proposed that the limtion ofStevioside and Rebaudioside A in Folium Steviae Rebaudianae should not be less than1%and2%, respectively.