Asparagin

Bezeichnung:Asparagin

CAS-Nr70-47-3

Englisch Name:L-Asparagine

CBNumberCB4375647

SummenformelC4H8N2O3

Molgewicht132.12

MOL-Datei70-47-3.mol

Synonyma

Asparagin

Asparagin physikalisch-chemischer Eigenschaften

Schmelzpunkt	235 °C (dec.) (lit.)
Siedepunkt	244.01°C (rough estimate)
alpha	34.5 º (c=10, 2N HCl)
Dichte	1,543g/cm
Brechungsindex	1.4880 (estimate)
storage temp.	Keep in dark place,Inert atmosphere,Room temperature
Löslichkeit	Practically insoluble in methanol, ethanol, ether, benzene. Soluble in acids and alkalies.
pka	2.17(at 20℃)
Aggregatzustand	Powder
Farbe	White
Geruch (Odor)	sltly sweet taste
PH	5.41
Optische Aktivität	-5.625 (H2O)+28.625 (1 mol dm-3 HCl)
Wasserlöslichkeit	H2O: 20 g/L (20 oC) , clear, colorless
Sensitive	Hygroscopic
Merck	14,837
BRN	1723527
Stabilität	Stable, but may be moisture-sensitive. Incompatible with strong oxidizing agents.
LogP	-3.820
CAS Datenbank	70-47-3(CAS DataBase Reference)
NIST chemische Informationen	L-Asparagine(70-47-3)
EPA chemische Informationen	L-Asparagine (70-47-3)

Sicherheit

Kennzeichnung gefährlicher	Xn
R-Sätze:	20/21/22-36/37/38
S-Sätze:	24/25-36-26
RIDADR	UN 2811 6.1 / PGIII
WGK Germany	3
F	3-10
TSCA	Y
HazardClass	IRRITANT
HS Code	29241900
Giftige Stoffe Daten	70-47-3(Hazardous Substances Data)

Gefahreninformationscode (GHS)

L-Asparagine Chemische Eigenschaften,Einsatz,Produktion Methoden

R-Sätze Betriebsanweisung:
R20/21/22:Gesundheitsschädlich beim Einatmen,Verschlucken und Berührung mit der Haut.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
S-Sätze Betriebsanweisung:
S24/25:Berührung mit den Augen und der Haut vermeiden.
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
Beschreibung
Asparagine (abbreviated as Asn or N) is one of the 20 most common natural amino acids on Earth. It has carboxamide as the sidechain's functional group. It is not an essential amino acid. Its codons are AAU and AAC.
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. In vivo, asparagine is hydrolyzed to aspartate and NH4+ by asparaginase. Asparagine is also an important amino acid in glycopeptide bonds, via N-glycosyl linkages to the sugar rings.
Chemische Eigenschaften
White crystal or crystalline powder with a slightly sweet taste. Slightly soluble in water, insoluble in ethanol and ether, it often exists as a monohydrate, and it is a rhombic hemihedral crystals. The melting point is 234-235°C , and the aminocarbonyl reaction is carried out by co-heating with sugar, which can form special aroma substances. The best recrystallization method is water, followed by ethanol. In case of alkali hydrolysis into aspartic acid. Heating its aqueous solution also decomposes. Natural products exist in various legumes and the like.
Physikalische Eigenschaften
Solubility 3.11 (28 ℃) g/100 g H2O, pI 5.41, dissociation constants: pK1 2.02, pK2 8.8.
Occurrence
Dietary sources
Asparagine is not essential for humans, which means that it can be synthesized from central metabolic pathway intermediates and is not required in the diet. Asparagine is found in :
Animal sources : dairy, whey, beef, poultry, eggs, fish, lactalbumin , sea food
Plant sources : asparagus, potatoes, legumes, nuts, seeds, soy, whole grains.
Biosynthesis
The precursor to asparagine is oxaloacetate. Oxaloacetate is converted to aspartate using a transaminase enzyme. The enzyme transfers the amino group from glutamate to oxaloacetate producing α- ketoglutarate and aspartate. The enzyme asparagine synthetase produces asparagine, AMP, glutamate, and pyrophosphate from aspartate, glutamine, and ATP. In the asparagine synthetase reaction, ATP is used to activate aspartate, forming β-aspartyl-AMP. Glutamine donates an ammonium group, which reacts with β-aspartyl-AMP to form asparagine and free AMP.
History
Asparagine was first isolated in 1806, under a crystalline form, by French chemists Louis Nicolas Vauquelin and Pierre Jean Robiquet (then a young assistant) from asparagus juice, in which it is abundant — hence, the name they chose for that new matter — becoming the first amino acid to be isolated.
A few years later, in 1809, Pierre Jean Robiquet again identified, this time from liquorice root, a substance with properties he qualified as very similar to those of asparagine, that Plisson in 1828 identified as asparagine itself.
Verwenden
L-asparagine has been used:
to identify and quantify free amino acids released upon oxidation of proteins and peptides by hydroxyl radicals.
to study the effects of amino acids in promoting food consumption in Drosophila melanogaster.
to study non-enzymatic gluconeogenesis.
L-Asparagine is used in cell culture media and is a component of MEM non-essential amino acids solution.
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. Spore germination in Bacillus subtilis has been increased in the presence of L-asparagine.
An isoxazoline RGD mimic platelet GPIIb/IIIa antagonist has been prepared by chiral synthesis with L-asparagine as a starting material. L-Asparagine has been utilized in the synthesis of 4-azalysine building blocks for application to combinatorial chemistry.
Definition
ChEBI: L-asparagine is an optically active form of asparagine having L-configuration. It has a role as a nutraceutical, a micronutrient, a human metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite, a mouse metabolite and a plant metabolite. It is an aspartate family amino acid, a proteinogenic amino acid, an asparagine and a L-alpha-amino acid. It is a conjugate base of a L-asparaginium. It is a conjugate acid of a L-asparaginate. It is an enantiomer of a D-asparagine. It is a tautomer of a L-asparagine zwitterion.
Vorbereitung Methode
A simple synthesis of L -asparagine starts from L -aspartic acid which is esterified to the b-methyl ester followed by treatment with ammonia.
Biologische Funktion
Asparagine is a dietarily dispensable amino acid synthesized from aspartate and glutamine. Asparagine has three major functions: 1) incorporation into amino acid sequences of proteins; 2) storage form for aspartate (is a required precursor for synthesis of DNA, RNA and ATP); and 3) source of amino groups for production of other dispensable amino acids via trasaminases.
The nervous system requires asparagine. It also plays an important role in the synthesis of ammonia.
The addition of N-acetyl glucosamine to asparagine is performed by oligosaccharyltransferase enzymes in the endoplasmic reticulum. This glycosylation is important both for protein structure and protein function.
Biochem/physiol Actions
L-asparagine is an uncharged derivative of aspartate. It possesses a polar side chain and is a non-essential amino acid.
Sicherheitsprofil
When heated to decomposition emits toxic fumes of Nox
läuterung methode
Likely impurities are aspartic acid and tyrosine. Crystallise it from H2O or aqueous EtOH. It slowly effloresces in dry air. [Greenstein & Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 p 1856 1961, Beilstein 4 IV 3005.]
Degradation
Aspartate is a glucogenic amino acid. L-asparaginase hydrolyzes the amide group to form aspartate and ammonium. A transaminase converts the aspartate to oxaloacetate, which can then be metabolized in the citric acid cycle or gluconeogenesis.

L-Asparagine Upstream-Materialien And Downstream Produkte

Asparagin Anbieter Lieferant Produzent Hersteller Vertrieb Händler.

70-47-3, L-Asparagine Verwandte Suche:

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