What Is the Structure of Alanine?

Alanine is the basic unit of protein and is one of the 20 amino acids that make up human proteins. Its molecular formula is C ₃ H ₇ NO ₂ and there are two isomers of -alanine and -alanine.

Alanine has

Industry: used to synthesize new sweeteners and certain chiral drugs

Chinese Pharmacopoeia 2015 Edition

This product is L-2-aminopropionic acid. Calculated on dry basis, containing C ₃ H ₇ NO ₂ shall not be less than 98.5%.

[ Properties ] This product is white or almost white crystal or crystalline powder; it has aroma.

This product is soluble in water, insoluble in ethanol, acetone or ether; soluble in 1mol / L hydrochloric acid solution.

Take the product of specific rotation , accurately weigh, add 1mol / L hydrochloric acid solution to dissolve and quantitatively dilute to make a solution containing about 50mg per 1ml, and measure according to law (General Rule 0621). .

[ Identification ] (1) Take appropriate amounts of this product and alanine reference substance, dissolve and dilute with water to make a solution containing about 10mg per 1ml, as the test solution and reference solution. According to the chromatographic conditions test under other amino acids, the position and color of the main spots displayed by the test solution should be the same as the main spots of the reference solution.

(2) The infrared absorption spectrum of this product should be consistent with the control spectrum (spectrum set 915).

[ Check ] Acidity Take 1.0g of this product, add 20ml of water to dissolve it, and measure it according to law (General Rule 0631). The pH value should be 5.5 7.0.

Solution transmittance Take 1.0g of this product, add 20ml of water to dissolve,

Method name: Alanine drugDetermination of AlanineNon-aqueous titration

Scope of application: This method uses the titration method to determine the content of alanine in alanine raw materials.

This method is applicable to alanine drug substances.

Principle of the method: After the anhydrous formic acid is dissolved, add glacial acetic acid, titrate with perchloric acid according to the potentiometric titration method, and correct the titration result with a blank test. Calculate the alanine based on the amount of titrant used. content.

Reagent: 1. Glacial acetic acid

Anhydrous formic acid

3. Perchloric acid titrant (0.1mol / L)

Crystal violet indicator liquid

5. Reference potassium phthalate

equipment:

Sample preparation: 1. Perchloric acid titration solution (0.1mol / L)

Preparation: Take 750mL of anhydrous glacial acetic acid (calculated with water content, add 5.22mL of acetic anhydride per 1g of water), add 8.5mL of perchloric acid (70 ~ 72%), shake well, let cool, add an appropriate amount of anhydrous glacial acetic acid 1000mL, shake well and leave for 24 hours. If the test sample is easily acetylated, the water content of the solution must be determined by the moisture measurement method, and then the water content of the solution is adjusted to 0.01% ~ 0.2% with water and acetic anhydride.

Calibration: Take about 0.16g of standard potassium hydrogen phthalate dried to constant weight at 105 , accurately weigh, add 20mL of anhydrous glacial acetic acid to dissolve, add 1 drop of crystal violet indicator solution, and slowly titrate with this solution to Blue, and the titration results are corrected with a blank test. Each 1mL of perchloric acid titration solution (0.1mol / L) is equivalent to 20.42mg of potassium hydrogen phthalate. Calculate the concentration of this solution based on the consumption of this solution and the amount of potassium hydrogen phthalate taken.

2. Crystal violet indicator liquid

Take 0.5 g of crystal violet and add 100 mL of glacial acetic acid to dissolve.

Operation steps: Precisely weigh about 80mg of the test sample, add 2mL of anhydrous formic acid to dissolve, add 30mL of glacial acetic acid, and titrate with perchloric acid titration solution (0.1mol / L) according to the potentiometric titration method. Blank test correction. Each 1mL of perchloric acid titration solution (0.1mol / L) is equivalent to 8.909mg of C ₃ H ₇ NO ₂ .

Note: "Precision weighing" means that the weighed weight should be accurate to one thousandth of the weighed weight. "Precision measurement" means that the accuracy of measuring the volume should meet the accuracy requirements of the volume pipette in national standards. ^[3]