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L-Cystein Produkt Beschreibung

CAS-Nr.52-90-4
Bezeichnung:L-Cystein
Englisch Name:L-Cysteine
Synonyma:
CYS;CYSH;E 920;L-Cys;Cystein;NSC-8746;CYSTEINE;H-CYS-OH;L-Cys-OH;FEMA 3263
CBNumber:CB7388480
Summenformel:C3H7NO2S
Molgewicht:121.16
MOL-Datei:52-90-4.mol
L-Cystein physikalisch-chemischer Eigenschaften
Schmelzpunkt:: 220 °C (dec.)(lit.)
alpha : 8.75 º (c=12, 2N HCl)
Dichte: 1.197 (estimate)
FEMA : 3263 | L-CYSTEINE
Brechungsindex: 8.8 ° (C=8, 1mol/L HCl)
storage temp. : Store at RT.
Löslichkeit: H2O: 25 mg/mL
pka: 1.92(at 25℃)
Aggregatzustand: Solid
Farbe: White
PH: 4.5-5.5 (100g/l, H2O, 20℃)
Optische Aktivität: Optical rotation: +8° to +9° (c = 5, 1 N HCl, 20°C).
Wasserlöslichkeit: 280 g/L (25 ºC)
Sensitive : Air Sensitive
maximale Wellenlänge (λmax): λ: 260 nm Amax: 1.5
λ: 280 nm Amax: 0.2
JECFA Number: 1419
Merck : 14,2781
BRN : 1721408
Stabilität:: Stability Stable, but may be air sensitive. Incompatible with oxidizing agents, bases.
CAS Datenbank: 52-90-4(CAS DataBase Reference)
NIST chemische Informationen: L-Cysteine(52-90-4)
EPA chemische Informationen: L-Cysteine(52-90-4)
Sicherheit
Kennzeichnung gefährlicher: Xn,Xi
R-Sätze:: 22-36/37/38-20/21/22
S-Sätze:: 36-37/39-26-24/25
WGK Germany : 3
RTECS-Nr.: HA1600000
F : 10-23
Selbstentzündungstemperatur: 420 °C
TSCA : Yes
HS Code : 29309012
Giftige Stoffe Daten: 52-90-4(Hazardous Substances Data)
Toxizität: LD50 orally in Rabbit: 1890 mg/kg

L-Cystein Chemische Eigenschaften,Einsatz,Produktion Methoden

R-Sätze Betriebsanweisung:
R22:Gesundheitsschädlich beim Verschlucken.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
R20/21/22:Gesundheitsschädlich beim Einatmen,Verschlucken und Berührung mit der Haut.
S-Sätze Betriebsanweisung:
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
S37/39:Bei der Arbeit geeignete Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
Beschreibung
Cysteine (abbreviated as Cys or C) is an α-amino acid with the chemical formula HO2CCH(NH2)CH2SH. It is a semi - essential amino acid, which means that it can be biosynthesized in humans. The thiol side chain in cysteine often participates in enzymatic reactions, serving as a nucleophile. The thiol is susceptible to oxidization to give the disulfide derivative cystine, which serves an important structural role in many proteins. When used as a food additive, it has the E number E920.
Chemische Eigenschaften
White crystalline powder
Occurrence
Dietary sources
Although classified as a non-essential amino acid, in rare cases, cysteine may be essential for infants, the elderly, and individuals with certain metabolic disease or who suffer from malabsorption syndromes. Cysteine can usually be synthesized by the human body under normal physiological conditions if a sufficient quantity of methionine is available.
Cysteine is catabolized in the gastrointestinal tract and blood plasma. In contrast, cystine travels safely through the GI tract and blood plasma and is promptly reduced to the two cysteine molecules upon cell entry.
Industrial sources
The majority of L - cysteine is obtained industrially by hydrolysis of poultry feathers or human hair. Synthetically produced L-cysteine, compliant with Jewish Kosher and Muslim Halal rules, is also available, albeit at a higher price. The synthetic route involves fermentation utilizing a mutant of E. coli.
Biosynthesis
In animals, biosynthesis begins with the amino acid serine. The sulfur is derived from methionine, which is converted to homocysteine through the intermediate S- adenosylmethionine. Cystathionine betasynthase then combines homocysteine and serine to form the asymmetrical thioether cystathionine. The enzyme cystathionine gamma-lyase converts the cystathionine into cysteine and alphaketobutyrate.
Occurrence
Dietary sources
Although classified as a non - essential amino acid, in rare cases, cysteine may be essential for infants, the elderly, and individuals with certain metabolic disease or who suffer from malabsorption syndromes. Cysteine can usually be synthesized by the human body under normal physiological conditions if a sufficient quantity of methionine is available. Cysteine is catabolized in the gastrointestinal tract and blood plasma . In contrast, cystine travels safely through the GI tract and blood plasma and is promptly reduced to the two cysteine molecules upon cell entry.
Cysteine is found in most high-protein foods, including :
Animal sources: pork, sausage meat, chicken, turkey, duck, luncheon meat, eggs, milk, whey protein, ricotta, cottage cheese, yogurt
Plant sources: red peppers, garlic, onions, broccoli, brussels sprout, oats, granola, wheat germ, sprouted lentils. Like other amino acids, cysteine has an amphoteric character.
Industrial sources
The majority of L-cysteine is obtained industrially by hydrolysis of poultry feathers or human hair. Synthetically produced L-cysteine, compliant with Jewish Kosher and Muslim Halal rules, is also available, albeit at a higher price . The synthetic route involves fermentation utilizing a mutant of E. coli. Degussa introduced a route from substituted thiazolines. Following this technology, L-cysteine is produced by the hydrolysis of racemic 2-amino-Δ22-thiazoline-4- carboxylic acid using Pseudomonas thiazolinophilum.
BiosynthesisIn animals, biosynthesis begins with the amino acid serine. The sulfur is derived from methionine, which is converted to homocysteine through the intermediate S- adenosylmethionine. Cystathionine betasynthase then combines homocysteine and serine to form the asymmetrical thioether cystathionine. The enzyme cystathionine gamma-lyase converts the cystathionine into cysteine and alphaketobutyrate. In plants and bacteria, cysteine biosynthesis again starts from serine, which is converted to O-acetylserine by the enzyme serine transacetylase. The enzyme O-acetylserine (thiol)-lyase, using sulfide sources, converts this ester into cysteine, releasing acetate.
Verwenden
L-Cysteine is a non-essential amino acid that can be synthesized by the human body under normal physiological conditions if a sufficient quantity of methionine is available. L-Cysteine is commonly use d as a precursor in the food and pharmaceutical industries. L-Cysteine is used as a processing aid for baking, as an additive in cigarettes, as well as in the preparation of meat flavours.
Verwenden
cysteine is an essential amino acid obtained by fermentation. Cysteine is a component of the skin’s natural moisturizing factor and can help normalize oil gland secretion because of its sulfur content. It is also said to promote wound healing. In addition, studies indicate that cysteine helps increase levels of glutathione (an anti-oxidant) in the body. It is considered beneficial in treating oily skin.
Verwenden
Cysteine is a nonessential amino acid that functions as a nutrient and dietary supplement. It is used in foods to prevent oxygen from destroying vitamin c and is used in doughs to reduce mixing time.
Application
Cysteine, mainly the L-enantiomer, is a precursor in the food, pharmaceutical, and personal care industries. One of the largest applications is the production of flavors. For example, the reaction of cysteine with sugars in a Maillard reaction yields meat flavors. Lcysteine is also used as a processing aid for baking.
In the field of personal care, cysteine is used for permanent wave applications predominantly in Asia. Again the cysteine is used for breaking up the disulfide bonds in the hair's keratin.
Cysteine is a very popular target for site-directed labeling experiments to investigate biomolecular structure and dynamics. Maleimides will selectively attach to cysteine using a covalent Michael addition. Site- directed spin labeling for EPR or paramagnetic relaxation enhanced NMR also uses cysteine extensively.
In a 1994 report released by five top cigarette companies, cysteine is one of the 599 additives to cigarettes. Like most cigarette additives, however, its use or purpose is unknown. Its inclusion in cigarettes could offer two benefits: Acting as an expectorant, since smoking increases mucus production in the lungs; and increasing the beneficial antioxidant glutathione (which is diminished in smokers).
Definition
ChEBI: An optically active form of cysteine having L-configuration.
Biologische Funktion
The cysteine thiol group is nucleophilic and easily oxidized. The reactivity is enhanced when the thiol is ionized, and cysteine residues in proteins have pKa values close to neutrality, so are often in their reactive thiolate form in the cell. Because of its high reactivity, the thiol group of cysteine has numerous biological functions.
Precursor to the antioxidant glutathione
Due to the ability of thiols to undergo redox reactions, cysteine has antioxidant properties. Cysteine's antioxidant properties are typically expressed in the tripeptide glutathione, which occurs in humans as well as other organisms.
Precursor to iron-sulfur clusters
Cysteine is an important source of sulfide in human metabolism. The sulfide in iron-sulfur clusters and in nitrogenase is extracted from cysteine, which is converted to alanine in the process.
Metal ion binding
Beyond the iron - sulfur proteins, many other metal cofactors in enzymes are bound to the thiolate substituent of cysteinyl residues. Examples include zinc in zinc fingers and alcohol dehydrogenase, copper in the blue copper proteins, iron in cytochrome P450, and nickel in the [NiFe]-hydrogenases . The thiol group also has a high affinity for heavy metals, so that proteins containing cysteine, such as metallothionein, will bind metals such as mercury, lead, and cadmium tightly.
Roles in protein structure
In the translation of messenger RNA molecules to produce polypeptides, cysteine is coded for by the UGU and UGC codons. Cysteine has traditionally been considered to be a hydrophilic amino acid, based largely on the chemical parallel between its thiol group and the hydroxyl groups in the side-chains of other polar amino acids. However, the cysteine side chain has been shown to stabilize hydrophobic interactions in micelles to a greater degree than the side chain in the non-polar amino acid glycine, and the polar amino acid serine .
Biologische Funktion
The cysteine thiol group is nucleophilic and easily oxidized. The reactivity is enhanced when the thiol is ionized, and cysteine residues in proteins have pKa values close to neutrality, so are often in their reactive thiolate form in the cell. Because of its high reactivity, the thiol group of cysteine has numerous biological functions.
1-Precursor to the antioxidant glutathione
2-Precursor to iron-sulfur clusters
3-Metal ion binding
4-Roles in protein structure.
Nebenwirkungen
Cysteine has been proposed as a preventative or antidote for some of the negative effects of alcohol, including liver damage and hangover. It counteracts the poisonous effects of acetaldehyde, which is the major by - product of alcohol metabolism and is responsible for most of the negative aftereffects and long - term damage associated with alcohol use (but not the immediate effects of drunkenness). Cysteine supports the next step in metabolism, which turns acetaldehyde into the relatively harmless acetic acid. In a rat study, test animals received an LD50 dose of acetaldehyde. Those that received cysteine had an 80 % survival rate; when both cysteine and thiamine were administered, all animals survived . There is not yet direct evidence for or against its effectiveness in humans who consume alcohol at normal levels.
N-Acetylcysteine
N - Acetyl - L - cysteine (NAC) is a derivative of cysteine wherein an acetyl group is attached to the nitrogen atom. This compound is sold as a dietary supplement and used as an antidote in cases of acetaminophen overdose, and obsessive compulsive disorders such as trichotillomania.
Nebenwirkungen
Cysteine has been proposed as a preventative or antidote for some of the negative effects of alcohol, including liver damage and hangover. It counteracts the poisonous effects of acetaldehyde, which is the major by-product of alcohol metabolism and is responsible for most of the negative aftereffects and long-term damage associated with alcohol use (but not the immediate effects of drunkenness). Cysteine supports the next step in metabolism, which turns acetaldehyde into the relatively harmless acetic acid. In a rat study, test animals received anLD50 dose of acetaldehyde. Those that received cysteine had an 80 % survival rate; when both cysteine and thiamine were administered, all animals survived. There is not yet direct evidence for or against its effectiveness in humans who consume alcohol at normal levels.
N-Acetylcysteine
N-Acetyl-L-cysteine (NAC) is a derivative of cysteine wherein an acetyl group is attached to the nitrogen atom. This compound is sold as a dietary supplement and used as an antidote in cases of acetaminophen overdose, and obsessive compulsive disorders such as trichotillomania.
Sicherheitsprofil
Moderately toxic by ingestion, intraperitoneal, and subcutaneous routes. Experimental reproductive effects. Human mutation data reported. When heated to decomposition fumes of SO and NO.
läuterung methode
Purify it by recrystallisation from H2O (free from metal ions) and dry it in a vacuum. It is soluble in H2O, EtOH, Me2CO, EtOAc, AcOH, *C6H6 and CS2. Acidic solutions can be stored under N2 for a few days without deterioration. [For synthesis and spectra see Greenstein & Winitz Chemistry of the Amino Acids (J. Wiley) Vol 3 p1879 1961, Beilstein 4 III 1618, 4 IV 3144.]
L-Cystein Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Schwefelwasserstoff Ammoniak, wssrige Lsung Cystin
Downstream Produkte
Acetylcystein Biotin Ranitidin Papain Cysteinhydrochlorid Carbocistein
L-Cystein Anbieter Lieferant Produzent Hersteller Vertrieb Händler.      Global( 468)Lieferanten     
Firmenname Telefon Fax E-Mail Land Produktkatalog Edge Rate
Shenzhen Sendi Biotechnology Co.Ltd.
0755-23311925 18102838259
0755-23311925Abel@chembj.com CHINA 3210 55
Henan DaKen Chemical CO.,LTD.
+86-371-55531817
info@dakenchem.com CHINA 22064 58
Beijing Cooperate Pharmaceutical Co.,Ltd.
+86-10-60279497 +86(0)15646567669
+86-10-60279497sales01@cooperate-pharm.com CHINA 1530 55
Henan Tianfu Chemical Co.,Ltd.
0371-55170693
0371-55170693info@tianfuchem.com CHINA 20743 55
Mainchem Co., Ltd.
+86-0592-6210733
+86-0592-6210733sales@mainchem.com CHINA 32606 55
Nanjing ChemLin Chemical Industry Co., Ltd.
025-83697070;product@chemlin.com.cn
product@chemlin.com.cn CHINA 3015 60
Jiangsu Qingquan Chemical Co., Ltd.
+86-571-86589381/86589382/86589383
lyy@qqpharm.comsales1@qqpharm.com CHINA 177 55
ATK CHEMICAL COMPANY LIMITED
+86 21 5161 9050/ 5187 7795
+86 21 5161 9052/ 5187 7796ivan@atkchemical.com CHINA 24212 60
Xiamen AmoyChem Co., Ltd
+86 (0)592-605 1114
sales@amoychem.com CHINA 6402 58
Chemwill Asia Co.,Ltd.
86-21-51086038
86-21-51861608chemwill_asia@126.com;sales@chemwill.com;chemwill@hotmail.com;chemwill@gmail.com CHINA 24093 58
 
52-90-4(L-Cystein)Verwandte Suche:
Levoglutamid Citrullin Arginin L-Cystein Cystin Trometamol Cysteinhydrochlorid Aminocapronsure AMINO ACIDS Glycin 3-Mercaptopropionsäure Thioglykolsäure (2-Ethylhexyl)-thioglykolat Ethyl-L-cysteinathydrochlorid Acetylcystein 2-Mercaptoethanol DL-Homocystein L-CYSTEINE HCL ANHYDROUS
L-Alanine, 3-mercapto- L-Amino-thopro-ponicacid L-Mercaptoalanine NSC-8746 Propanoic Acid, 2-amino-3-mercapto-, (R)- Thioserine cysteine,b-mercapto-alanine L-CYSTEINE FREE BASE, BIOTECHNOLOGY & L(+)-CYSTEINE BIOSYNTH L-CYSTEINE 97+% L-Cysteine>99% L-CysteineForBiochemistry-(R)-3-Amino-3-MercaptopropionicAcid) L-CysteineForBiochemistry L-CysteineForBiochemistry99+% L-Cysteine,98+% L-CYSTEINE, PHARMA L-Cysteine-1-13C L-CYSTEINUM l-2-amino-3-mercaptopropionic acid (2R)-2-amino-3-sulfanyl-propanoic acid CYTISINE(LABURNIN)(RG) b-Mercaptoalanine E 920 L-Cys L-Cysteine (9CI) (+)-2-Amino-3-mercaptopropionic acid L-CYSTEINE extrapure CHR L-Cysteine produced by Wacker Chemie AG, Burghausen, Germany, >=98.0% Acetylcysteine EP Impurity B-13C3 Acetylcysteine EP Impurity B (L-Cysteine) (R)-(+)-CYSTEINE (R)-2-AMINO-3-MERCAPTOPROPIONIC ACID BETA-MERCAPTO-L-ALANINE CYSTEINE CYSTEINE, L- CYS CYSH FEMA 3263 H-CYS-OH L-2-AMINO-3-MERCAPTOPROPANOIC ACID L-beta-Mercaptoalanine L(+)-CYSTEIN L-(+)-CYSTEINE (R)-2-Amino-3-mercaptopropanoic acid 3-mercapto-l-alanin alpha-amino-beta-mercaptopropionicacid alpha-Amino-beta-thiolpropionic acid alpha-amino-beta-thiolpropionicacid Cystein half-cysteine L-Cysteine Vetec(TM) reagent grade, 97% MAXIMUM RECOVERY DILUENT (ISO) SOYA PEPTONE - GMO AND ANIMAL FREE Acetylcysteine Impurity B (L-Cysteine) L-Cys-OH L-CYSTEINE BIOULTRA, >= 98& L-Cysteine≥ 99% (Titration: anhydrous basis) L-Cysteine from non-animal source≥ 99% (Assay)
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