| 外観 | 白色の結晶性粉末 |
| 定義 | 本品は、次の化学式で表されるアミノ酸である。 |
| 溶解性 | 水に溶けやすく、エタノール及びジエチルエーテルにほとんど溶けない。 |
| 解説 | グリシン．略号Gly．グリココルともいう．もっとも簡単なα-アミノ酸で，生体アミノ酸のなかで唯一不斉炭素原子をもたない．動物，植物にタンパク質構成アミノ酸として，または遊離の形で広く分布している．大豆ミール，くずまゆ，絹フィブロイン，ゼラチンなどの加水分解物からエチルエステル塩酸塩や金属塩として分離される．実験室的には，ホルムアルデヒドとシアン化水素とアンモニアから合成する(ストレッカーのアミノ酸合成)，工業的には，モノクロロ酢酸とアンモニアから合成する．分解点292 ℃．pK1 2.34，pK2 9.60．pI5.97．苦味がある．医薬，食料品加工，ほかのアミノ酸の合成原料などに用いられる． |
| 用途 | 食品類醸造用原料( 添加物) 、医薬中間原料 |
| 化粧品の成分用途 | ヘアコンディショニング剤、緩衝剤、皮膚コンディショニング剤 |
| 効能 | グリシン補充薬 |
| 確認試験 | 本品を乾燥し，赤外吸収スペクトル測定法〈2.25〉
の臭化カリウム錠剤法により試験を行い，本品のスペクトル
と本品の参照スペクトルを比較するとき，両者のスペクトル
は同一波数のところに同様の強度の吸収を認める．もし，こ
れらのスペクトルに差を認めるときは，本品を水に溶かし，
蒸発乾燥したものにつき，同様の試験を行う． |
| 定量法 | 本品を乾燥し，その約80mgを精密に量り，ギ酸3mL
に溶かし，酢酸(100)50mLを加え，0.1mol/L過塩素酸で滴
定〈2.50〉する(電位差滴定法)．同様の方法で空試験を行い，
補正する． |
| 純度試験 | (１) 溶状 本品1.0gを水10mLに溶かすとき，液は無色澄
明である．
(２) 塩化物〈1.03〉 本品0.5gをとり，試験を行う．比較
液には0.01mol/L塩酸0.30mLを加える(0.021％以下)．
(３) 硫酸塩〈1.14〉 本品0.6gをとり，試験を行う．比較
液には0.005mol/L硫酸0.35mLを加える(0.028％以下)．
(４) アンモニウム〈1.02〉 本品0.25gをとり，試験を行う．
比較液にはアンモニウム標準液5.0mLを用いる(0.02％以下)．
(５) 重金属〈1.07〉 本品1.0gをとり，第1法により操作し，
試験を行う．比較液には鉛標準液2.0mLを加える(20ppm以
下)．
(６) ヒ素 本品1.0gをとり，第1法により操作し，
試験を行う(2ppm以下)．
(７) 類縁物質 本品0.10gを水25mLに溶かし，試料溶液
とする．この液1mLを正確に量り，水を加えて正確に50mL
とする．この液5mLを正確に量り，水を加えて正確に20mL
とし，標準溶液とする．これらの液につき，薄層クロマトグ
ラフィー〈2.03〉により試験を行う．試料溶液及び標準溶液
5μLずつを薄層クロマトグラフィー用シリカゲルを用いて調
製した薄層板にスポットする．次に1－ブタノール／水／酢
酸(100)混液(3：1：1)を展開溶媒として約10cm展開した後，
薄層板を80℃で30分間乾燥する．これにニンヒドリンのア
セトン溶液(1→50)を均等に噴霧した後，80℃で5分間加熱
するとき，試料溶液から得た主スポット以外のスポットは，
標準溶液から得たスポットより濃くない． |
| 貯法 | 容器 密閉容器． |
| 乾燥減量 | 0.30％以下(1g，105℃，3時間)． |
| 強熱残分 | 0.1％以下(1g)． |
| 説明 | Glycine (abbreviated as Gly or G) is an organic compound with the formula NH2CH2COOH. 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). |
| 化学的特性 | Glycine occurs as a white, odorless, crystalline powder, and has a
sweet taste. |
| 化学的特性 | Glycine is odorless and has a slightly sweet taste. |
| 化学的特性 | A white, odorless, crystalline powder having a sweetish taste. Its
solution is acid to litmus. One g dissolves in about 4 mL of water.
It is very slightly soluble in alcohol and in ether. Glycine may be
prepared from chloroacetic acid and ammonia; from protein
sources, such as gelatin and silk fibroin; from ammonium bicarbonate
and sodium cyanide; by catalytic cleavage of serine; from
hydrobromic acid and methyleneaminoacetonitrile. |
| 天然物の起源 | Gelatin and silk fbroin are reportedly the best natural sources of this amino acid |
| 使用 | Glycine is a nonessential amino acid that functions as a nutrient and
dietary supplement. it has a solubility of 1 g in 4 ml of water and is
abundant in collagen. it is used to mask the bitter aftertaste of sac-
charin, for example, in artificially sweetened soft drinks. it retards
rancidity in fat. |
| 使用 | glycine is an amino acid used as a texturizer in cosmetic formulations. It makes up approximately 30 percent of the collagen molecule. |
| 使用 | In the US, glycine is typically sold in two grades: United States Pharmacopeia (“USP”), and technical grade. Most glycine is manufactured as USP grade material for diverse uses. USP grade sales account for approximately 80 to 85 percent of the U.S. market for glycine.
Pharmaceutical grade glycine is produced for some pharmaceutical applications, such as intravenous injections, where the customer’s purity requirements often exceed the minimum required under the USP grade designation. Pharmaceutical grade glycine is often produced to proprietary specifications and is typically sold at a premium over USP grade glycine.
Technical grade glycine, which may or may not meet USP grade standards, is sold for use in industrial applications; e.g., as an agent in metal complexing and finishing. Technical grade glycine is typically sold at a discount to USP grade glycine.
Animal and human foods
Other markets for USP grade glycine include its use an additive in pet food and animal feed. For humans, glycine is sold as a sweetener/taste enhancer. Certain food supplements and protein drinks contain glycine. Certain drug formulations include glycine to improve gastric absorption of the drug.
Cosmetics and miscellaneous applications
Glycine serves as a buffering agent in antacids, analgesics, antiperspirants, cosmetics, and toiletries.
Many miscellaneous products use glycine or its derivatives, such as the production of rubber sponge products, fertilizers, metal complexants.
Chemical feed stock
Glycine is an intermediate in the synthesis of a variety of chemical products. It is used in the manufacture of the herbicide glyphosate. Glyphosate is a non-selective systemic herbicide used to kill weeds, especially perennials and broadcast or used in the cutstump treatment as a forestry herbicide. |
| 使用 | Non-essential amino acid for human development. An inhibitory neurotransmitter in spinal cord, allosteric regulator of NMDA receptors. |
| 使用 | Glycine is a non-essential amino acid for human development. Glycine is an inhibitory neurotransmitter in spinal cord, allosteric regulator of NMDA receptors. |
| 定義 | ChEBI: The simplest (and the only achiral) proteinogenic amino acid, with a hydrogen atom as its side chain. |
| 調製方法 | Glycine was discovered in 1820, by Henri Braconnot who boiled gelatin with sulfuric acid.
Glycine is manufactured industrially by treating chloroacetic acid with ammonia :
ClCH2COOH + 2 NH3→H2NCH2COOH + NH4Cl
About 15 million kg are produced annually in this way.
In the USA (by GEO Specialty Chemicals, Inc.) and in Japan (by Shoadenko), glycine is produced via the Strecker amino acid synthesis. |
| 製造方法 | 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. |
| 調製方法 | 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. |
| 生合成 | 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 +N5,N10-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 : CO2 + NH4+ + N5,N10-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. |
| Biotechnological Production | Glycine is manufactured exclusively by chemical synthesis, and two main processes
are practiced today. The direct amination of chloroacetic acid
with a large excess of ammonia gives good yields of glycine without producing
large amounts of di- and trialkylated products. This process is widely used in
China, where the main application of the glycine is as a raw material for the
herbicide glyphosate.
The other main process is the Strecker synthesis. The direct Strecker reaction of
formaldehyde and ammonium cyanide produces methylene amino acetonitrile,
which must be hydrolyzed in two stages to produce glycine . A more efficient
approach is to aminate the intermediate glycolonitrile, followed by hydrolysis].
An alternative method, which is more often applied for the homologous amino
acids, is the Bucherer–Bergs reaction. Reaction of formaldehyde and ammonium
carbonate or bicarbonate gives the intermediate hydantoin, which can be hydrolyzed
to glycine in a separate step. |
| 生物学の機能 | 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 C2N 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. . |
| 生物学の機能 | Glycine is another inhibitory CNS neurotransmitter.
Whereas GABA is located primarily in the brain,
glycine is found predominantly in the ventral horn of
the spinal cord. Relatively few drugs are known to interact
with glycine; the best-known example is the convulsant
agent strychnine, which appears to be a relatively
specific antagonist of glycine. |
| 一般的な説明 | White crystals. |
| 空気と水の反応 | Water soluble. |
| 反応プロフィール | 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. |
| 危険性 | Use in fats restricted to 0.01%. |
| 火災危険 | LOW. Ignites at very high temperatures. |
| 农业用途 | Glycine is the simplest naturally occurring amino acid and is a constituent of most proteins. Its formula is H2N·CH2·COOH. |
| 応用例（製薬） | 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. |
| 生物活性 | 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™ . |
| Biochem/physiol Actions | Glycine has a pivotal role in lowering the plasma lipid levels in diabetic and obese patients by activating the CNS. During brain hypoxia glycine can stabilize the energetics disturbances in brain mitochondria. It also increases the in vitro development of porcine blastocysts when used along with glucose. |
| 安全性プロファイル | Moderately toxic by
intravenous route. Mildly toxic by ingestion.
Mutation data reported. When heated to
decomposition it emits toxic fumes of NOx. |
| 安全性 | 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 |
| 貯蔵 | 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. |
| 純化方法 | 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.] |
| Degradation | Glycine is degraded via three pathways. The predominant pathway in animals and plants involves the glycine cleavage enzyme Glycine + tetra hydro folate + NAD+ → CO2 + NH4+ + N5,N10-Methylene tetra hydrofolate + NADH + H+ In the second pathway, glycine is degraded in two steps. The first step is the reverse of glycine biosynthesis from serine with serine hydroxymethyl transferase. Serine is then converted to pyruvate by serine dehydratase. In the third pathway of glycine degradation, glycine is converted to glyoxylate by D-amino acid oxidase. Glyoxylate is then oxidized by hepatic lactate dehydrogenase to oxalate in an NAD+-dependent reaction. The half-life of glycine and its elimination from the body varies significantly based on dose. In one study, the half-life was between 0.5 and 4.0 hours. |
| Presence in space | The detection of glycine in the interstellar medium has been debated . In 2008, the glycine - like molecule amino aceto nitrile was discovered in the Large Molecule Heimat, a giant gas cloud near the galactic center in the constellation Sagittarius by the Max Planck Institute for Radio Astronomy . In 2009, glycine sampled in 2004 from comet Wild 2 by the NASA spacecraft Stardust was confirmed, the first discovery of extraterrestrial glycine. That mission's results bolstered the theory of panspermia, which claims that the "seeds" of life are widespread throughout the universe. |
| 不和合性 | 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. |
| 規制状況(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. |