DEFINITION<\/h2>\n
(RS)-2-Acetylamino-3-(1H-indol-3-yl)propanoic acid.<\/p>\n
Content<\/h3>\n
99.0 per cent to 101.0 per cent (dried substance).<\/p>\n
PRODUCTION<\/h2>\n
Tryptophan used for the production of N-acetyltryptophan complies with the test for impurity A and other related substances in the monograph on Tryptophan (1272).<\/p>\n
CHARACTERS<\/h2>\nAppearance<\/h3>\n
White or almost white, crystalline powder, or colourless crystals.<\/p>\n
Solubility<\/h3>\n
Slightly soluble in water, very soluble in ethanol (96 per cent). It dissolves in dilute solutions of alkali hydroxides.<\/p>\n
mp<\/h3>\n
About 205 \u00b0C.<\/p>\n
IDENTIFICATION<\/h2>\n
First identification: A, B.<\/p>\n
Second identification: A, C, D, E.<\/p>\n
A. Optical rotation (see Tests).<\/p>\n
B. Infrared absorption spectrophotometry (2.2.24).<\/p>\n
Comparison N-acetyltryptophan CRS.<\/p>\n
C. Thin-layer chromatography (2.2.27).<\/p>\n
Test solution: Dissolve 50 mg of the substance to be examined in 0.2 mL of concentrated ammonia R and dilute to 10 mL with water R.<\/p>\n
Reference solution (a): Dissolve 50 mg of N-acetyltryptophan CRS in 0.2 mL of concentrated ammonia R and dilute to 10 mL with water R.<\/p>\n
Reference solution (b): Dissolve 10 mg of tryptophan R in the test solution and dilute to 2 mL with the test solution.<\/p>\n
Plate: TLC silica gel F254 plate R.<\/p>\n
Mobile phase: glacial acetic acid R, water R, butanol R (25:25:40 V\/V\/V).<\/p>\n
Application: 2 \u03bcL.<\/p>\n
Development: Over a path of 10 cm.<\/p>\n
Drying: In an oven at 100-105 \u00b0C for 15 min.<\/p>\n
Detection: Examine in ultraviolet light at 254 nm.<\/p>\n
System suitability: Reference solution (b):<\/p>\n
\u2014 the chromatogram shows 2 clearly separated spots.<\/p>\n
Results: The principal spot in the chromatogram obtained with the test solution is similar in position and size to the principal spot in the chromatogram obtained with reference solution (a).<\/p>\n
D. Dissolve about 2 mg in 2 mL of water R. Add 2 mL of dimethylaminobenzaldehyde solution R6. Heat on a water-bath. A blue or greenish-blue colour develops.<\/p>\n
E. It gives the reaction of acetyl (2.3.1). Proceed as described for substances hydrolysable only with difficulty.<\/p>\n
TESTS<\/h2>\nAppearance of solution<\/h3>\n
The solution is clear (2.2.1) and not more intensely coloured than reference solution Y7 or GY7 (2.2.2, Method II).<\/p>\n
Dissolve 1.0 g in a 40 g\/L solution of sodium hydroxide R and dilute to 100 mL with the same alkaline solution.<\/p>\n
Optical rotation (2.2.7)<\/h4>\n
-0.1\u00b0 to + 0.1\u00b0.<\/p>\n
Dissolve 2.50 g in a 40 g\/L solution of sodium hydroxide R and dilute to 25.0 mL with the same alkaline solution.<\/p>\n
Related substances<\/h3>\n
Liquid chromatography (2.2.29). Prepare the test and reference solutions immediately before use.<\/p>\n
Buffer solution: pH 2.3 Dissolve 3.90 g of sodium dihydrogen phosphate R in 1000 mL of water R. Add about 700 mL of a 2.9 g\/L solution of phosphoric acid R and adjust to pH 2.3 with the same acid solution.<\/p>\n
Solvent mixture: acetonitrile R, water R (10:90 V\/V).<\/p>\n
Test solution: Dissolve 0.10 g of the substance to be examined in a mixture of 50 volumes of acetonitrile R and 50 volumes of water R and dilute to 20.0 mL with the same mixture of solvents.<\/p>\n
Reference solution (a): Dilute 1.0 mL of the test solution to 100.0 mL with the solvent mixture.<\/p>\n
Reference solution (b): Dilute 4.0 mL of reference solution (a) to 100.0 mL with the solvent mixture.<\/p>\n
Reference solution (c): Dissolve the contents of a vial of 1,1\u2032-ethylidenebistryptophan CRS in 1 mL of reference solution (b).<\/p>\n
Column:<\/p>\n
\u2014 size: l = 0.25 m, \u00d8 = 4.6 mm;<\/p>\n
\u2014 stationary phase: octadecylsilyl silica gel for chromatography R (5 \u03bcm);<\/p>\n
\u2014 temperature: 40 \u00b0C.<\/p>\n
Mobile phase:<\/p>\n
\u2014 mobile phase A: acetonitrile R, buffer solution pH 2.3 (115:885 V\/V);<\/p>\n
\u2014 mobile phase B: acetonitrile R, buffer solution pH 2.3 (350:650 V\/V);<\/p>\n
| Time<\/strong> \n(min)<\/strong><\/td>\n Mobile phase A<\/strong> | \n(per cent V\/V)<\/strong><\/td>\n Mobile phase B<\/strong> | \n(per cent V\/V)<\/strong><\/td>\n<\/tr>\n 0 – 10<\/td>\n | \u00a0100<\/td>\n | \u00a00<\/td>\n<\/tr>\n | 10 – 45<\/td>\n | \u00a0100 \u2192 0<\/td>\n | \u00a00 \u2192 100<\/td>\n<\/tr>\n | 45 – 65<\/td>\n | \u00a00<\/td>\n | \u00a0100<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n | Flow rate: 0.7 mL\/min.<\/p>\n Detection: Spectrophotometer at 220 nm.<\/p>\n Injection:20 \u03bcL of the test solution and reference solutions (a) and (c).<\/p>\n Retention time: N-acetyltryptophan = about 29 min; 1,1\u2032-ethylidenebis(tryptophan) = about 34 min.<\/p>\n System suitability: Reference solution (c):<\/p>\n \u2014 resolution: minimum 8.0 between the peaks due to N-acetyltryptophan and 1,1\u2032-ethylidenebis(tryptophan); if necessary, adjust the time programme for the elution gradient (an increase in the duration of elution with mobile phase A produces longer retention times and a better resolution);<\/p>\n \u2014 symmetry factor: maximum 3.5 for the peak due to 1,1\u2032-ethylidenebistryptophan in the chromatogram obtained with reference solution (c).<\/p>\n Limits:<\/p>\n \u2014 impurities A, B, C, D, E, F, G, H, I, J, K, L: for each impurity, not more than 0.25 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.25 per cent);<\/p>\n \u2014 total: not more than 0.5 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.5 per cent);<\/p>\n \u2014 disregard limit: 0.01 times the area of the principal peak the chromatogram obtained with reference solution (a) (0.01 per cent).<\/p>\n Ammonium (2.4.1, Method B)<\/h3>\nMaximum 200 ppm, determined on 0.10 g.<\/p>\n Prepare the standard using 0.2 mL of ammonium standard solution (100 ppm NH4) R.<\/p>\n Iron (2.4.9)<\/h3>\nMaximum 10 ppm.<\/p>\n Dissolve 1.0 g in 50 mL of hydrochloric acid R1, with heating at 50 \u00b0C. Allow to cool. In a separating funnel, shake with 3 quantities, each of 10 mL, of methyl isobutyl ketone R1, shaking for 3 min each time. To the combined organic layers add 10 mL of water R and shake for 3 min. Examine the aqueous layer.<\/p>\n Loss on drying (2.2.32)<\/h4>\nMaximum 0.5 per cent, determined on 1.000 g by drying in an oven at 105 \u00b0C.<\/p>\n Sulfated ash (2.4.14)<\/h4>\nMaximum 0.1 per cent, determined on 1.0 g.<\/p>\n ASSAY<\/h2>\nDissolve 0.200 g in 5 mL of methanol R. Add 50 mL of anhydrous ethanol R. Titrate with 0.1 M sodium hydroxide, determining the end-point potentiometrically (2.2.20).<\/p>\n 1 mL of 0.1 M sodium hydroxide is equivalent to 24.63 mg of C13<\/sub>H14<\/sub>N2<\/sub>O3<\/sub><\/p>\n Protected from light.<\/p>\n Specified impurities A, B, C, D, E, F, G, H, I, J, K, L.<\/p>\n A. (S)-2-amino-3-(1H-indol-3-yl)propanoic acid (tryptophan),<\/p>\n B. (S)-2-amino-3-[(3RS)-3-hydroxy-2-oxo-2,3-dihydro-1H-indol-3-yl]propanoic acid (dioxyindolylalanine),<\/p>\n C. (S)-2-amino-4-(2-aminophenyl)-4-oxobutanoic acid (kynurenine),<\/p>\n D. (S)-2-amino-3-(5-hydroxy-1H-indol-3-yl)propanoic acid (5-hydroxytryptophan),<\/p>\n E. (S)-2-amino-4-[2-(formylamino)phenyl]-4-oxobutanoic acid (N-formylkynurenine),<\/p>\n F. (S)-2-amino-3-(phenylamino)propanoic acid (3-phenylaminoalanine),<\/p>\n G. (S)-2-amino-3-(2-hydroxy-1H-indol-3-yl)propanoic acid (2-hydroxytryptophan),<\/p>\n H. (3RS)-1,2,3,4-tetrahydro-9H-\u03b2-carboline-3-carboxylic acid,<\/p>\n I. 1-methyl-1,2,3,4-tetrahydro-9H-\u03b2-carboline-3-carboxylic acid,<\/p>\n J. (S)-2-amino-3-[2-[2,3-dihydroxy-1-(1H-indol-3-yl)propyl]-1H-indol-3-yl]propanoic acid,<\/p>\n K. (S)-2-amino-3-[2-(1H-indol-3-ylmethyl)-1H-indol-3-yl]propanoic acid,<\/p>\n L. 1-(1H-indol-3-ylmethyl)-1,2,3,4-tetrahydro-9H-\u03b2-carboline-3-carboxylic acid.<\/p>\n","protected":false},"excerpt":{"rendered":" (N-Acetyltryptophan, Ph. Eur. monograph 1383) C13H14N2O3\u00a0 \u00a0 \u00a0 246.3\u00a0 \u00a0 \u00a0 87-32-1 DEFINITION (RS)-2-Acetylamino-3-(1H-indol-3-yl)propanoic acid. Content 99.0 per cent to 101.0 per cent (dried substance). PRODUCTION Tryptophan used for the production of N-acetyltryptophan complies with the test for impurity A and other related substances in the monograph on Tryptophan (1272). CHARACTERS Appearance White or almost…<\/p>\n","protected":false},"author":2,"featured_media":1215,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-1204","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-medicinal-substances"],"acf":[],"_links":{"self":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/1204","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=1204"}],"version-history":[{"count":5,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/1204\/revisions"}],"predecessor-version":[{"id":6874,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/1204\/revisions\/6874"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/1215"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=1204"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=1204"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=1204"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}} |
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