91小视频 I 天天射综合 I 蜜臀在线观看 I 亚洲美女一区 I 亚洲精品在线免费 I 日韩在线高清 I 一道本在线观看 I 国产女人毛片 I 欧美在线观看一区二区三区 I 成人综合激情网 I 最新日本中文字幕 I 黄色无毒网站 I 激情视频免费观看 I 伊人影视网 I 欧美日韩一级大片 I 在线观看日本网站 I 成人h动漫在线 I 亚洲国产成人精品激情在线 I 在线看日本 I 69xx网站 I 熟女俱乐部一区二区 I 一级人爱视频 I 国产精品网站免费 I 欧美毛片免费看 I 四虎av影视 I 日韩中出 I 久久日韩精品 I 久草热视频

sigmaL-天冬酰胺

L-Asparagine monohydrate
Product Number A 8381
Store at Room Temperature
Product Description
Molecular Formula: C4H8N2O3 • H2O
Molecular Weight: 150.1
CAS Number: 5794-13-8
pKa: 2.14 （-COOH）, 8.72 （-NH2）1
pI: 5.431
Specific Rotation: +32.6°
（10 mg/ml, 0.1 M HCl, 20 °C）
Melting Point: 234-235 °C2
Synonyms: （S）-2-aminosuccinic acid 4-amide,
L-aspartic acid 4-amide, α-aminoauccinamic acid,
aspartic acid β-amide2
The amino acid L-asparagine is a structural analog of
L-aspartic acid, where the side chain of the carboxylic
acid moiety is amidated, to give a terminal amine
group. This renders L-asparagine neutral at
physiological pH. The amide group of asparagine is
derived from glutamate, in the reaction of aspartate
and glutamine in the presence of ATP to yield
asparagine and glutamate.3 In vivo, asparagine is
hydrolyzed to aspartate and NH4
+ by asparaginase.4
Asparagine is also an important amino acid in
glycopeptide bonds, via N-glycosyl linkages to the
sugar rings.3
L-Asparagine is used in cell culture media and is a
component of MEM non-essential amino acids solution
（Product No. M 7145）. L-Asparagine has been shown
to enhance ornithine decarboxylase activity in cultured
human colon adenocarcinoma Caco-2 cells and in
cultured IEC-6 intestinal epithelial cells.5,6 Spore
germination in Bacillus subtilis has been increased in
the presence of L-asparagine.7
An isoxazoline RGD mimic plaet GPIIb/IIIa
antagonist has been prepared by chiral synthesis with
L-asparagine as a starting material.8 L-Asparagine
has been utilized in the synthesis of 4-azalysine
building blocks for application to combinatorial
chemistry.9
Precautions and Disclaimer
For Laboratory Use Only. Not for drug, household or
other uses.
Preparation Instructions
This product is soluble in water （50 mg/ml）, with heat
as needed, yielding a clear, colorless solution.
References
1. Molecular Biology Lab, Brown, T. A., ed., BIOS
Scientific Publishers （Oxford, UK: 1991）, p. 29.
2. The Merck Index, 12th ed., Entry# 872.
3. Textbook of Biochemistry with Clinical
Correlations, 5th ed., Devlin, T. M., ed., Wiley-Liss
（New York, NY: 2002）, pp. 97, 680-681, 785-786.
4. Biochemistry, 3rd ed., Stryer, L., W. H. Freeman
（New York, NY: 1988）, pp. 18, 504.
5. Chabanon, H., et al., Increased translation
efficiency and antizyme-dependent stabilization of
ornithine decarboxylase in amino acidsupplemented
human colon adenocarcinoma
cells, Caco-2. Biochem. J., 348（Pt 2）, 401-408
（2000）.
6. Ray, R. M., et al., Interaction of asparagine and
EGF in the regulation of ornithine decarboxylase in
IEC-6 cells. Am. J. Physiol., 276（3 Pt 1）, G773-
780.
7. Cabrera-Martinez, R. M., et al., Effects of
overexpression of nutrient receptors on
germination of spores of Bacillus subtilis. J.
Bacteriol., 185（8）, 2457-2464 （2003）.
8. Zhang L. H., et al., The Enantiospecific synthesis
of an isoxazoline. A RGD mimic plaet GPIIb/IIIa
antagonist. J. Org. Chem., 62（8）, 2466-2470
（1997）.
9. Chhabra, S. R., et al., Homochiral 4-azalysine
building blocks: syntheses and applications in
solid-phase chemistry. J. Org. Chem., 67（12）,
4017-4029 （2002）.
GCY/RXR 8/03
Sigma brand

sigmaL-天冬酰胺 詳細產(chǎn)品信息可和選購