木瓜的英语说范文Word文档下载推荐.docx

1、 Papain 9001-73-4 Papain is a purified proteolytic substance derived from Carica papaya Linn（Fam.caricaceae）.papain,when assayed directed herein, contains not less than 6000 units per mg. Papain of a higher digestive power may be reduced to the official standard by admixture with papain of lower act

2、ivity ,lactose,or other suitable diluents. One USP Unit of papain is the activity that releases the of 1g of tyrosine from a specified casein substance under the conditions of the Assay， using the enzyme concentration that liberates 40g of tyrosine per mL of test solution. Packaging and storagePrese

3、rve in tight,light-resistant containers in a cool place. USP reference standards （11）USP papain RS. pH:between 4.8 and 6.2 in a solution （1 in 50）. Loss on drying Dry it in a vacuum oven at 60 for 4 hours : it losses not more than 7.0% of its weight. Assay （casein digestive power） Dibasic sodium pho

4、sphate.,0.05Mdissolve 7.1g of anhydrous dibasic sodium phosphate in water to make 1000mL.add 1 drop of toluene as a preservative. Citric acid,0.05Mdissolve 10.5g of citric acid monohydrate in water to make 1000mL. Add 1 drop on toluene as a preservative. Casein substrateDisperse 1 g of Hammersten-ty

5、pe casein in 50 mL on 0.05M Dibasic sodium phosphate. Place in a boiling water bath for 30 minutes with oasional stirring.Cool to room temperature ,and add 0.05 M Citric acid to adjust to a pH of 6.00.1.stir the solution rapidly and continuously during the addition of the 0.05M Citric acid to preven

6、t precipitation of the casein. Dilute with water to 100 mL .prepare fresh daily. Buffer solution （Phosphate-Cysteine Disodium ethylenediamietraacetate Buffer） Trichloroacetic acid solution Dissolve 30g of reagent grade trichloroacetic acid in water. and dilute with water to 100mL. This solution may

7、be stored at room temperature. Standard preparation Weigh aurately 100 mg of USP Papain RS in a 100-mL volumetric flask. And add Buffer solution to dissolve. Dilute with Buffer solution to volume, and mix. Transfer 2.0 mL of this solution to a 50-mL volumetric flask, dilute with Buffer solution to v

8、olume, and mix. Use within 30 minutes after preparation. Assay preparationTransfer an aurately weighed amount of papain.,equivalent to about 100mg of USP Papain RS, to a 10-mL volumetric flask, dilute with Buffer solution to volume, and mix. Transfer 2.0 mL of this solution to a 50-mL volumetric fls

9、k, dilute with Buffer solution to volume, and mix. ProcedureInto each of 12 test tubes （18-150-mm） pipet 5.0 mL of casein substrate. Place in a water bath at 40, and allow 10 minutes to reach bath temperature. Into each of two of the tubes （the tests are run in duplicate except for the blanks） label

10、ed S1 ,pipet 1.0 mL of the Standard preparation and 1.0mL of the Buffer solution, Mix by swirling , note zero time,insert the stopper, and replace in the bath . Into each of 2 other tubes ,labeled S2 pipet 1.5mL of standard . preparation and 0.5 mL of Buffer solution , and proceed as before . Repeat

11、 this procedure for 2 tubes ,labeled S3to which 2.0mL of standard preparation is added , and for 2 tube ,labled U2,to which 1.5mL of Assay preparation and 0.5mL Buffer solution are added.After 60 minutes,aurary timed,add to all 12 tubes 3.0 mL of trichloroacetic acid solution,and shake vigorously .

12、With the 4 tubes to which no standard preparation or Assay preparation were added,prepare blanks by pipeting,respectively ,1.0mL of standard preparation and 1.0 mL of Buffer solution 1.5mL of standard preparation and 0.5 mL of Buffer solution;2.0mL of standard preparation;and 1.5mL Assay preparation

13、 and 0.5 mL of Buffer solution.Replace all tubes in the 40 water bath for 30 to 40 minutes,to allow to coagulate fully the precipitated protein.Filter through medium-porosity filter paper,discarding the first 3 mL of the filtrate（filtrates used are clear）.Read the absorbances at 280 nm,of the filtra

14、tes if all solutions against their respective blanks.Plot the absorbance readings for S1,S2- and S3 against the enzyme concentration of each corresponding level.By interpolation from this curve,taking into consideration dilution factors,calculate the potency in Units,in the weight of papain taken by

15、 the formula.: （50,000/3）CA, In which 50,000/3 is a factor derived by the expression 100（50/2）（10/1.5）,C is the concentration,in mg per mL,obtained from the standard curve,and A is the activity of the Reference Standard in Units per mg. 翻译仅供参考： 木瓜蛋白酶 木瓜蛋白酶9001-73-4 木瓜蛋白酶是一种源自番木瓜乳汁（Fam.caricaceae）的纯化的水解蛋白物。木瓜蛋白酶在这里定向检测时其含量不得少于6000单位每毫克。具有较高的消化能力的木瓜蛋白酶也许可以通过掺加低活力的木瓜蛋白酶，乳糖或者其他合适的填充物来降低消化能力以达到官方的标准。 定义木瓜蛋白酶一个USP活力单位为在测定条件下指定的酪蛋白物质释放1g酪氨酸所需要的量，所用的酶试液的浓度相当与每毫升释放40g酪氨酸 。 包装与保藏包装要包紧，保存在避光，阴凉的地方 USP 参考标准（11）USP 木瓜蛋白酶 R.S pH在溶液中介于4.8与6.2之间（1 in 50？） 干燥失重60时在真空干燥箱中干燥4