Investigation On Quality Standard Of Dioscoreae Rhizoma Pieces

Yam is the dried rhizome of Dioscorea dioscorea(Dioscorea opposita Thunb.),which has the effect of strengthening the spleen and nourishing the stomach,promoting the lungs and nourishing the lungs,and tonifying the kidney and removing the essence.The chemical constituents of yam include polysaccharides,yam compounds,allantoin,amino acids,fatty acids,trace elements,starch,protein,etc.,which have pharmacological effects such as hypoglycemic,hypolipidemic,anti-oxidative,spleen and stomach,anti-tumor,immune regulation,etc.The project of yam contained in the 2015 edition of the Chinese Pharmacopoeia includes microscopic identification,thin layer identification,moisture,total ash,sulfur dioxide residue and acid-insoluble ash content of the extract,no content determination,and TLC identified by reference materials,lacking of characteristic index composition,the standard can not fully reflect and control the quality of yam.At present,the yam pieces on the market are graded by diameter.Due to the different regions and growing environments,the quality is also very different.This study explores the chemical composition of yam by finding the appropriate index components,establishing the quality standards of yam,including thin layer identification,content determination,characteristic maps,etc.,and discussing the classification criteria of yam.Provide scientific basis for the reasonable evaluation of the quality of Chinese herbal medicines.1.Thin layer identification method: Batatasin I,a characteristic indicator of Chinese yam,was obtained by reference data and chemical separation.Batatasin I was selected as the indicator component,silica gel was used as the stationary phase,and the hexane-ethyl acetate-98% formic acid solution(9:3:0.2)was used as the developing solvent,and the 10% sulfuric acid ethanol solution was used as the color developing agent,and the yam TLC identification method was established.2.Moisture and heavy metal pesticide residue inspection items: Determination of moisture in 70 batches of yam from different origins and batches,the water limit is the same as the 2015 edition of the Chinese Pharmacopoeia: The moisture of the mountain tablets(ie fresh slices)shall not exceed 12.0%.The Maoshan tablets and the Guangshan tablets shall be the same as the herbs,that is,the moisture shall not exceed 16.0%.lead must not exceed 0.27 mg/kg,cadmium should not exceed 0.01 mg/kg,arsenic should not exceed 0.31 mg/kg,mercury should not exceed 0.02 mg/kg,copper No more than 6.93 mg/kg;aflatoxin G2,G1,B2,B1 shall not be detected;?-BHC,?-BHC,?-BHC,?-BHC,p,p'-DDE,o,p'-DDT,p,p'-DDD,p,p'-DDT,and pentachloronitrobenzene should not be detected.3.HPLC chromatogram: chromatographic conditions: column: Agilent ZORBAX SB-C18(4.6 x 250 mm,5 ?m);mobile phase: acetonitrile(A)-water(B),0-5 min,35%(A);5-35 min,35-55%(A);35-45 min,55-90%(A);detection wavelength was 275 nm;column temperature: 30 ?;flow rate: 1.0 m L/min;Six characteristic peaks should be presented in the characteristic map of the test product.The relative peaks of the characteristic peaks and the S peaks should be calculated with the corresponding peaks as reference peaks.The relative retention time should be within ±5% of the specified value.The relative retention time values are 0.40(peak 1),0.60(peak 2),0.62(peak 3),0.80(peak 4),1.00(peak 5(S)),and 1.05(peak 6).4.Determination method of total polysaccharide content: The extraction method and content determination method of yam polysaccharide were established by single factor experiment.The method was determined by ultraviolet spectrophotometry.Glucose was used as reference substance and the detection wavelength was 490 nm.The yam pieces were produced from different places and batches.Determination of total polysaccharide content.The results showed that the content of yam polysaccharides in different producing areas and batches varied greatly,ranging from 3.92% to 30.63%.5.HPLC method for determination of allantoin HPLC: chromatographic conditions: column: XBridge Amide(4.6 x 250 mm,3.5 ?m);mobile phase: acetonitrile(A)-water(B),0-5 min,90%(A);-15 min,90-88%(A);detection wavelength: 210 nm;column temperature: 35 ?;flow rate: 1.0 m L / min;the number of theoretical plates should be no less than 11000 according to the peak of allantoin.Allantoin is linear in the range of 27.5?220.0?g/m L,and the precision,stability,repeatability and accuracy of the method are good.The content of allantoin in 70 batches of yam pieces was determined.The results showed that allantoin ranged from 0.10% to 1.10%.6.The standard of yam decoction pieces: establish the classification standard of yam decoction pieces,which are divided into three specifications: fresh slice,Guangshan pill and Maoshan pill.The fresh slice and Guangshan pill are divided into three grades according to their diameters,and the yam yam is not graded.The fresh slice is a sulfur-free drying sheet,and the Guangshan tablet is a dry slice,including a chamfer and a round cut.Correlation analysis of grade specifications and data on polysaccharides and allantoin content has almost no correlation,so the grade standards are still based on traditional classifications such as traits and diameters.The content limit established in this paper can be used to judge whether the pieces are qualified.Only the pieces that meet the quality standards can be classified.