Glycin Chemische Eigenschaften,Einsatz,Produktion Methoden
R-S?tze Betriebsanweisung:
R33:Gefahr kumulativer Wirkungen.
S-S?tze Betriebsanweisung:
S22:Staub nicht einatmen.
S24/25:Berührung mit den Augen und der Haut vermeiden.
Beschreibung
Glycine (abbreviated as Gly or G) is an organic compound with the formula NH
2CH
2COOH. Having a hydrogen substituent as its side-chain, glycine is the smallest of the 20 amino acids commonly found in proteins. Its codons are GGU, GGC, GGA, GGG of the genetic code.
Glycine is a colourless, sweet-tasting crystalline solid. It is unique among the proteinogenic amino acids in that it is not chiral. It can fit into hydrophilic or hydrophobic environments, due to its minimal side chain of only one hydrogen atom. Glycine is also the genus name of the Soybean plant (species name = Glycine max).
Chemische Eigenschaften
Glycine occurs as a white, odorless, crystalline powder, and has a
sweet taste.
Occurrence
Gelatin and silk fbroin are reportedly the best natural sources of this amino acid
Verwenden
Glycine is a non-essential amino acid for human development. Glycine is an inhibitory neurotransmitter in spinal cord, allosteric regulator of NMDA receptors.
Definition
ChEBI: The simplest (and the only achiral) proteinogenic amino acid, with a hydrogen atom as its side chain.
synthetische
From chloroacetic acid and ammonia; from protein sources, such as gelatin and silk fbroin; from ammonium bicarbonate and sodium cyanide; by catalytic cleavage of serine; from hydrobromic acid and methyleneaminoacetonitrile.
Vorbereitung Methode
Chemical synthesis is the most suitable method of preparation of
glycine. Amination of chloroacetic acid and the hydrolysis of
aminoacetonitrile are the favored methods of production.
Biosynthese
Glycine is not essential to the human diet, as it is biosynthesized in the body from the amino acid serine, which is in turn derived from 3-phospho glycerate. In most organisms, the enzyme Serine hydroxy methyl transferase catalyses this transformation via the cofactor pyridoxal phosphate :
serine + tetra hydro folate → glycine +N
5,N
10-Methylene tetrahydrofolate + H2O
In the liver of vertebrates, glycine synthesis is catalyzed by glycine synthase (also called glycine cleavage enzyme). This conversion is readily reversible : CO
2 + NH4
+ + N
5,N
10-Methylene tetra hydro folate + NADH + H
+→ Glycine + tetrahydrofolate +NAD
+Glycine is coded by codons GGU, GGC, GGA and GGG. Most proteins incorporate only small quantities of glycine. A notable exception is collagen, which contains about 35 % glycine.
Biologische Funktion
The principal function of glycine is as a precursor to proteins. It is also a building block to numerous natural products.
As a biosynthetic intermediate
In higher eukaryotes, D-Aminolevulinic acid, the key precursor to porphyrins, is biosynthesized from glycine and succinyl-CoA. Glycine provides the central C
2N subunit of all purines.
As a neurotransmitter
Glycine is an inhibitory neurotransmitter in the central nervous system, especially in the spinal cord, brainstem, and retina. When glycine receptors are activated, chloride enters the neuron via ionotropic receptors, causing an Inhibitory postsynaptic potentia (IPSP). Strychnine is a strong antagonist at ionotropic glycine receptors, whereas bicuculline is a weak one. Glycine is a required coagonist along with glutamate for NMDA receptors. In contrast to the inhibitory role of glycine in the spinal cord, this behaviour is facilitated at the (NMDA) glutaminergic receptors which are excitatory. The LD50 of glycine is 7930 mg / kg in rats (oral), and it usually causes death by hyperexcitability. .
Allgemeine Beschreibung
White crystals.
Air & Water Reaktionen
Water soluble.
Reaktivit?t anzeigen
An amino acid. A 0.2M aqueous solution has a pH of 4.0., so acts as a weak acid. Has characteristics of both acid and base.
Hazard
Use in fats restricted to 0.01%.
Brandgefahr
LOW. Ignites at very high temperatures.
Pharmazeutische Anwendungen
Glycine is routinely used as a cofreeze-dried excipient in protein
formulations owing to its ability to form a strong, porous, and
elegant cake structure in the final lyophilized product. It is one
of the most frequently utilized excipients in freeze-dried injectable
formulations owing to its advantageous freeze-drying properties.
Glycine has been investigated as a disintegration accelerant in
fast-disintegrating formulations owing to its excellent wetting
nature.It is also used as a buffering agent and conditioner in
cosmetics.
Glycine may be used along with antacids in the treatment of
gastric hyperacidity, and it may also be included in aspirin
preparations to aid the reduction of gastric irritation.
Landwirtschaftliche Anwendung
Glycine is the simplest naturally occurring amino acid and is a constituent of most proteins. Its formula is H
2N·CH
2·COOH.
Biologische Aktivit?t
One of the major inhibitory neurotransmitters in the mammalian CNS, predominantly active in the spinal cord and brain stem. Also acts as a modulator of excitatory amino acid transmission mediated by NMDA receptors. Also available as part of the NMDA Receptor - Glycine Site Tocriset™ .
Sicherheitsprofil
Moderately toxic by
intravenous route. Mildly toxic by ingestion.
Mutation data reported. When heated to
decomposition it emits toxic fumes of NOx.
Sicherheit(Safety)
Glycine is used as a sweetener, buffering agent, and dietary
supplement. The pure form of glycine is moderately toxic by the
IV route and mildly toxic by ingestion.
Systemic absorption of glycine irrigation solutions can lead to
disturbances of fluid and electrolyte balance and cardiovascular and
pulmonary disorders.
LD50 (mouse, IP): 4.45 g/kg
LD50 (mouse, IV): 2.37 g/kg
LD50 (mouse, oral): 4.92 g/kg
LD50 (mouse, SC): 5.06 g/kg
LD50 (rat, IV): 2.6 g/kg
LD50 (rat, oral): 7.93 g/kg
LD50 (rat, SC): 5.2 g/kg
Lager
Glycine starts to decompose at 233°C. Store in well-closed
containers. Glycine irrigation solutions (95–105% glycine) should
be stored in single dose containers, preferably type I or type II glass.
l?uterung methode
Crystallise glycine from distilled water by dissolving at 90-95o, filtering, cooling to about -5o, and draining the crystals centrifugally. Alternatively, crystallise it from distilled water by addition of MeOH or EtOH (e.g. 50g dissolved in 100mL of warm water, and 400mL of MeOH is added). The crystals are washed with MeOH or EtOH, then with diethyl ether. Likely impurities are ammonium glycinate, iminodiacetic acid, nitrilotriacetic acid or/and ammonium chloride. [Greenstein & Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 p 1955 1961, Beilstein 4 IV 2349.]
Inkompatibilit?ten
Glycine may undergo Maillard reactions with amino acids to
produce yellowing or browning. Reducing sugars will also interact
with secondary amines to form an imine, but without any
accompanying yellow-brown discoloration.
Regulatory Status
GRAS listed. Accepted for use as a food additive in Europe.
Included in the FDA Inactive Ingredients Database (IM, IV, SC
injections; oral; rectal) and approved for irrigant solutions. Included
in parenteral (powders for injection; solutions for injection;
vaccines; kits for implant) and nonparenteral (orodispersible
tablets/oral lyophilizate; powders for inhalation; powders for oral
solution; tablets) formulations licensed in the UK.
Glycin Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
Thiamphenicol
Hippursure
Zinc glycinate
3-(2-Thienyl)-L-serin
Leflunomide
2,2,3,3-TETRAMETHYLCYCLOPROPANECARBOXYLIC ACID
2,2-Dimethyl-3-(2-methylpropyl)cyclopropanecarboxylic acid p-(methoxymethyl)benzyl ester
Tiopronin
Antistaling agent
4-Methyl-3-nitroanisol
6-Methoxy-1H-indol
3,4,5-Trimethoxybenzylamin
novel anticancer microsphere with multifunction
2-Iodhippursure
1-Acetamidozimtsaeure
5-Methoxy-o-toluidin
N-Benzyloxycarbonylglycin
N-[N-[N-(N-L-Tyrosylglycyl)glycyl]-L-phenylalanyl]-L-methionin
3-Chlorbenzylamin
DL-Threonin
N-(p-Toluoyl)glycin
Hydantoinsure
6-Methoxy-1H-indole-3-carbaldehyde
TOSUFLOXACIN TOSILATE
Glyphosin
2,4,6-TRIFLUOROPHENYL ISOTHIOCYANATE
2-Hydroxy-3-phenyl-L-alanin
Methylglycinathydrochlorid
1H-TETRAZOLE-1-ACETYL CHLORIDE
3-(3,5-Dichlorphenyl)-2,4-dioxo-N-isopropylimidazolidin-1-carboxamid
(6-ETHYL-THIENO[2,3-D]PYRIMIDIN-4-YLAMINO)-ACETIC ACID
N-(2-Cyanethyl)glycin
DL-Serin
Ciclopirox
Tacrin
N-(tert-Butoxycarbonyl)glycin
Synthetic greasing agent
Dimethoxymethan
3-METHYLHIPPURIC ACID
4-Chlor-o-toluidin
