Glycine

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Glycine [1]
Glycine-2D-skeletal.svg
Skeletal formula of neutral glycine
Glycine-zwitterion-2D-skeletal.svg
Skeletal formula of zwitterionic glycine
Glycine-neutral-Ipttt-conformer-3D-bs-17.png
Ball-and-stick model of the gas-phase structure
Glycine-zwitterion-from-xtal-3D-bs-17.png
Ball-and-stick model of the zwitterionic solid-state structure
Glycine-neutral-Ipttt-conformer-3D-sf.png
Space-filling model of the gas-phase structure
Glycine-zwitterion-from-xtal-3D-sf.png
Space-filling model of the zwitterionic solid-state structure
Names
IUPAC name
Glycine
Systematic IUPAC name
Aminoacetic acid [2]
Other names
  • 2-Aminoethanoic acid
  • Glycocol
  • Glycic acid
  • Dicarbamic acid
Identifiers
3D model (JSmol)
AbbreviationsGly, G
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.000.248 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 200-272-2
  • 227-841-8
E number E640 (flavour enhancer)
KEGG
PubChem CID
UNII
  • InChI=1S/C2H5NH2/c3-1-2(4)5/h1,3H2,(H,4,5) Yes check.svgY
    Key: DHMQDGOQFOQNFH-UHFFFAOYSA-N Yes check.svgY
  • InChI=1S/C2H5NO2/c3-1-2(4)5/h1,3H2,(H,4,5)
    Key: DHMQDGOQFOQNFH-UHFFFAOYAW
  • C(C(=O)O)N
  • Zwitterion:C(C(=O)[O-])[NH3+]
  • C(C(=O)O)N.Cl
Properties
C2H5NO2
Molar mass 75.067 g·mol−1
AppearanceWhite solid
Density 1.1607 g/cm3 [3]
Melting point 233 °C (451 °F; 506 K) (decomposition)
249.9 g/L (25 °C) [4]
Solubility soluble in pyridine
sparingly soluble in ethanol
insoluble in ether
Acidity (pKa)2.34 (carboxyl), 9.6 (amino) [5]
−40.3·10−6 cm3/mol
Pharmacology
B05CX03 ( WHO )
Hazards
Lethal dose or concentration (LD, LC):
2600 mg/kg (mouse, oral)
Supplementary data page
Glycine (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)
L-Glycine ball and stick model spinning Glycine-spin.gif
L-Glycine ball and stick model spinning

Glycine (symbol Gly or G; [6] /ˈɡlaɪsiːn/ ⓘ [7] ) is an organic compound with the formula C2H5NO2, and is the simplest stable amino acid, distinguished by having a single hydrogen atom as its side chain. As one of the 20 proteinogenic amino acids, glycine is a fundamental building block of proteins in all life and is encoded by all codons starting with GG (GGU, GGC, GGA, and GGG). [8] [9] Because of its minimal side chain, it is the only common amino acid that is not chiral, meaning it is superimposable on its mirror image. [10] [11]

In the body, glycine plays several crucial roles. Its small and flexible structure is vital for the formation of certain protein structures, most notably in collagen, where glycine makes up about 35% of the amino acid content and enables the tight coiling of the collagen triple helix. [8] [12] Glycine disrupts the formation of alpha-helices in secondary protein structure, in favor instead of random coils. [13] Beyond its structural role, glycine functions as an inhibitory neurotransmitter in the central nervous system, [14] particularly in the spinal cord and brainstem, where it helps regulate motor and sensory signals. Disruption of glycine signaling can lead to severe neurological disorders and motor dysfunction; [15] for example, the tetanus toxin causes spastic paralysis by blocking glycine release. [16] It also serves as a key precursor for the synthesis of other important biomolecules, including the porphyrins that form heme in blood and the purines used to build DNA and RNA. [8]

Glycine is a white, sweet-tasting crystalline solid, leading to its name from Greek word glykys (Greek : γλυκύς) or "sweet". [17] [7] While the body can synthesize it, it is also obtained from the diet and produced industrially by chemical synthesis for use as a food additive, a nutritional supplement, and an intermediate in the manufacture of products such as the herbicide glyphosate. [18] In aqueous solutions, glycine exists predominantly as a zwitterion (H3N+CH2COO-), a polar molecule with both a positive and negative charge, making it highly soluble in water. [19] It can also fit into hydrophobic environments due to its minimal side chain. [20]

History and etymology

Glycine was discovered in 1820 by French chemist Henri Braconnot when he hydrolyzed gelatin by boiling it with sulfuric acid. [21] He originally called it "sugar of gelatin", [22] [23] but French chemist Jean-Baptiste Boussingault showed in 1838 that it contained nitrogen. [24] In 1847 American scientist Eben Norton Horsford, then a student of the German chemist Justus von Liebig, proposed the name "glycocoll"; [25] [26] however, the Swedish chemist Berzelius suggested the simpler current name a year later. [27] [28] The name comes from the Greek word γλυκύς "sweet tasting" [29] (which is also related to the prefixes glyco- and gluco- , as in glycoprotein and glucose ). In 1858, the French chemist Auguste Cahours determined that glycine was an amine of acetic acid. [30]

Production

Although glycine can be isolated from hydrolyzed proteins, this route is not used for industrial production, as it can be manufactured more conveniently by chemical synthesis. [31] The two main processes are amination of chloroacetic acid with ammonia, giving glycine and hydrochloric acid, [32] and the Strecker amino acid synthesis, [33] which is the main synthetic method in the United States and Japan. [34] About 15 thousand tonnes are produced annually in this way. [35]

Glycine is also co-generated as an impurity in the synthesis of EDTA, arising from reactions of the ammonia co-product. [36]

Chemical reactions

Its acid–base properties are most important. In aqueous solution, glycine is amphoteric: below pH = 2.4, it converts to the ammonium cation called glycinium. Above about pH 9.6, it converts to glycinate.

Glycine-protonation-states-2D-skeletal.png

Glycine functions as a bidentate ligand for many metal ions, forming amino acid complexes. [37] A typical complex is Cu(glycinate)2, i.e. Cu(H2NCH2CO2)2, which exists both in cis and trans isomers. [38] [39]

With acid chlorides, glycine converts to the amidocarboxylic acid, such as hippuric acid [40] and acetylglycine. [41] With nitrous acid, one obtains glycolic acid (van Slyke determination). With methyl iodide, the amine becomes quaternized to give trimethylglycine, a natural product:

H
3N+
CH
2COO−
 + 3 CH3I → (CH
3)
3N+
CH
2COO−
 + 3 HI

Glycine condenses with itself to give peptides, beginning with the formation of glycylglycine: [42]

2 H
3N+
CH
2COO−
 → H
3N+
CH
2CONHCH
2COO−
 + H2O

Pyrolysis of glycine or glycylglycine gives 2,5-diketopiperazine, the cyclic diamide. [43]

Glycine forms esters with alcohols. They are often isolated as their hydrochloride, such as glycine methyl ester hydrochloride. Otherwise, the free ester tends to convert to diketopiperazine.

As a bifunctional molecule, glycine reacts with many reagents. These can be classified into N-centered and carboxylate-center reactions.

Metabolism

Biosynthesis

Glycine is not strictly essential to the human diet, as it is biosynthesized in the body. However, it is considered semi-essential in that the amount that can be biosynthesized is insufficient for all metabolic uses. [44]

It can be synthesized from the amino acid serine, which is in turn derived from 3-phosphoglycerate. In most organisms, the enzyme serine hydroxymethyltransferase catalyses this transformation via the cofactor pyridoxal phosphate: [45]

serine + tetrahydrofolate → glycine + N5,N10-methylene tetrahydrofolate + H2O

In E. coli, antibiotics that target folate depletes the supply of active tetrahydrofolates, halting glycine biosynthesis as a consequence. [46]

In the liver of vertebrates, glycine synthesis is catalyzed by glycine synthase (also called glycine cleavage enzyme). This conversion is readily reversible: [45]

CO2 + NH+
4 + N5,N10-methylene tetrahydrofolate + NADH + H+ ⇌ Glycine + tetrahydrofolate + NAD +

In addition to being synthesized from serine, glycine can also be derived from threonine, choline or hydroxyproline via inter-organ metabolism of the liver and kidneys. [47]

Degradation

Glycine is degraded via three pathways. The predominant pathway in animals and plants is the reverse of the glycine synthase pathway mentioned above. In this context, the enzyme system involved is usually called the glycine cleavage system: [45]

Glycine + tetrahydrofolate + NAD+ ⇌ CO2 + NH+
4 + N5,N10-methylene tetrahydrofolate + 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. [45]

In the third pathway of its 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. [45]

The half-life of glycine and its elimination from the body varies significantly based on dose. [48] In one study, the half-life varied between 0.5 and 4.0 hours. [48]

Physiological function

The principal function of glycine is it acts as a precursor to proteins. Most proteins incorporate only small quantities of glycine, a notable exception being collagen, which contains about 35% glycine due to its periodically repeated role in the formation of collagen's helix structure in conjunction with hydroxyproline. [45] [49] In the genetic code, glycine is coded by all codons starting with GG, namely GGU, GGC, GGA and GGG. [9]

As a biosynthetic intermediate

In higher eukaryotes, δ-aminolevulinic acid, the key precursor to porphyrins, is biosynthesized from glycine and succinyl-CoA by the enzyme ALA synthase. Glycine provides the central C2N subunit of all purines. [45]

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 potential (IPSP). Strychnine is a strong antagonist at ionotropic glycine receptors, whereas bicuculline is a weak one. Glycine is a required co-agonist 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) glutamatergic receptors which are excitatory. [50] The LD50 of glycine is 7930 mg/kg in rats (oral), [51] and it usually causes death by hyperexcitability.[ citation needed ]

As a toxin conjugation agent

Glycine conjugation pathway has not been fully investigated. [52] Glycine is thought to be a hepatic detoxifier of a number endogenous and xenobiotic organic acids. [53] Bile acids are normally conjugated to glycine in order to increase their solubility in water. [54]

The human body rapidly clears sodium benzoate by combining it with glycine to form hippuric acid which is then excreted. [55] The metabolic pathway for this begins with the conversion of benzoate by butyrate-CoA ligase into an intermediate product, benzoyl-CoA, [56] which is then metabolized by glycine N-acyltransferase into hippuric acid. [57]

Uses

In the US, glycine is typically sold in two grades: United States Pharmacopeia ("USP"), and technical grade. USP grade sales account for approximately 80 to 85 percent of the U.S. market for glycine. If purity greater than the USP standard is needed, for example for intravenous injections, a more expensive pharmaceutical grade glycine can be used. Technical grade glycine, which may or may not meet USP grade standards, is sold at a lower price for use in industrial applications, e.g., as an agent in metal complexing and finishing. [58]

Animal and human foods

Structure of cis-Cu(glycinate)2(H2O) Cu(gly)2(OH2).png
Structure of cis-Cu(glycinate)2(H2O)

Glycine is not widely used in foods for its nutritional value, except in infusions. Instead, glycine's role in food chemistry is as a flavorant. It is mildly sweet, and it counters the aftertaste of saccharine. It also has preservative properties, perhaps owing to its complexation to metal ions. Metal glycinate complexes, e.g. copper(II) glycinate are used as supplements for animal feeds. [35]

As of 1971, the U.S. Food and Drug Administration "no longer regards glycine and its salts as generally recognized as safe for use in human food", [60] and only permits food uses of glycine under certain conditions. [61]

Glycine has been researched for its potential to extend life. [62] [63] The proposed mechanisms of this effect are its ability to clear methionine from the body, and activating autophagy. [62]

Chemical feedstock

Glycine is an intermediate in the synthesis of a variety of chemical products. It is used in the manufacture of the herbicides glyphosate, [64] iprodione, glyphosine, imiprothrin, and eglinazine. [35] It is used as an intermediate of antibiotics such as thiamphenicol. [65]

Laboratory research

Glycine is a significant component of some solutions used in the SDS-PAGE method of protein analysis. It serves as a buffering agent, maintaining pH and preventing sample damage during electrophoresis. [66] Glycine is also used to remove protein-labeling antibodies from Western blot membranes to enable the probing of numerous proteins of interest from SDS-PAGE gel. This allows more data to be drawn from the same specimen, increasing the reliability of the data, reducing the amount of sample processing, and number of samples required. [67] This process is known as stripping.

Presence in space

The presence of glycine outside the Earth was confirmed in 2009, based on the analysis of samples that had been taken in 2004 by the NASA spacecraft Stardust from comet Wild 2 and subsequently returned to Earth. Glycine had previously been identified in the Murchison meteorite in 1970. [68] The discovery of glycine in outer space bolstered the hypothesis of so-called soft-panspermia, which claims that the "building blocks" of life are widespread throughout the universe. [69] In 2016, detection of glycine within Comet 67P/Churyumov–Gerasimenko by the Rosetta spacecraft was announced. [70]

The detection of glycine outside the Solar System in the interstellar medium has been debated. [71]

Evolution

Glycine is proposed to be defined by early genetic codes. [72] [73] [74] [75] For example, low complexity regions (in proteins), that may resemble the proto-peptides of the early genetic code are highly enriched in glycine. [75]

Presence in foods

Food sources of glycine [76]
FoodPercentage
content
by weight
(g/100g)
Dry unsweetened gelatin powder19
Snacks, pork skins 11.04
Sesame seeds flour (low fat)3.43
Beverages, protein powder (soy-based)2.37
Seeds, safflower seed meal, partially defatted2.22
Meat, bison, beef and others (various parts)1.5–2.0
Gelatin desserts1.96
Seeds, pumpkin and squash seed kernels1.82
Turkey, all classes, back, meat and skin1.79
Chicken, broilers or fryers, meat and skin1.74
Pork, ground, 96% lean / 4% fat, cooked, crumbles1.71
Bacon and beef sticks1.64
Peanuts 1.63
Crustaceans, spiny lobster1.59
Spices, mustard seed, ground1.59
Salami 1.55
Nuts, butternuts, dried1.51
Fish, salmon, pink, canned, drained solids1.42
Almonds 1.42
Fish, mackerel 0.93
Cereals ready-to-eat, granola, homemade0.81
Leeks, (bulb and lower-leaf portion), freeze-dried0.7
Cheese, parmesan (and others), grated0.56
Soybeans, green, cooked, boiled, drained, without salt0.51
Bread, protein (includes gluten)0.47
Egg, whole, cooked, fried0.47
Beans, white, mature seeds, cooked, boiled, with salt0.38
Lentils, mature seeds, cooked, boiled, with salt0.37

See also

References

  1. ↑ The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (11th ed.). Merck. 1989. ISBN   091191028X.,4386
  2. ↑ "Glycine". PubChem.
  3. ↑ Handbook of Chemistry and Physics, CRC Press, 59th ed., 1978.[ page needed ]
  4. ↑ "Solubilities and densities". Prowl.rockefeller.edu. Archived from the original on September 12, 2017. Retrieved November 13, 2013.
  5. ↑ Dawson, R.M.C., et al., Data for Biochemical Research, Oxford, Clarendon Press, 1959.[ page needed ]
  6. ↑ "Nomenclature and Symbolism for Amino Acids and Peptides". IUPAC-IUB Joint Commission on Biochemical Nomenclature. 1983. Archived from the original on October 9, 2008. Retrieved March 5, 2018.
  7. 1 2 "Glycine | Definition of glycine in English by Oxford Dictionaries". Archived from the original on January 29, 2018.
  8. 1 2 3 Berg JM, Tymoczko JL, Gatto GJ Jr, Stryer L (2015). Biochemistry (8th ed.). New York: W. H. Freeman and Company. p. 35. ISBN   978-1-4641-2610-9.
  9. 1 2 Pawlak K, Błażej P, Mackiewicz D, Mackiewicz P (January 2023). "The Influence of the Selection at the Amino Acid Level on Synonymous Codon Usage from the Viewpoint of Alternative Genetic Codes". International Journal of Molecular Sciences. 24 (2): 1185. doi: 10.3390/ijms24021185 . PMC   9866869 . PMID   36674703.
  10. ↑ Matsumoto A, Ozaki H, Tsuchiya S, Asahi T, Lahav M, Kawasaki T, et al. (April 2019). "Achiral amino acid glycine acts as an origin of homochirality in asymmetric autocatalysis". Organic & Biomolecular Chemistry. 17 (17): 4200–4203. doi: 10.1039/C9OB00345B . PMID   30932119.
  11. ↑ IUPAC, ed. (2014). "achiral". Compendium of Chemical Terminology (2nd ed.). International Union of Pure and Applied Chemistry. doi:10.1351/goldbook.A00292.
  12. ↑ Nelson DL, Cox MM (2021). Lehninger Principles of Biochemistry (8th ed.). New York: W.H. Freeman. p. 129. ISBN   978-1-319-22800-2.
  13. ↑ Pace CN, Scholtz JM (1998). "A helix propensity scale based on experimental studies of peptides and proteins". Biophysical Journal. 75 (1): 422–427. Bibcode:1998BpJ....75..422N. doi:10.1016/S0006-3495(98)77529-0. PMC   1299714 . PMID   9649402.
  14. ↑ Zafra F, Aragón C, Giménez C (June 1997). "Molecular biology of glycinergic neurotransmission". Molecular Neurobiology. 14 (3): 117–142. doi:10.1007/BF02740653. PMID   9294860.
  15. ↑ Atchison W (2018). "Toxicology of the Neuromuscular Junction". Comprehensive Toxicology. pp. 259–282. doi:10.1016/B978-0-12-801238-3.99198-0. ISBN   978-0-08-100601-6.
  16. ↑ Purves D, Augustine GJ, Fitzpatrick D, Hall WC, LaMantia AS, White LE, eds. (2018). Neuroscience (6th ed.). Sunderland, Massachusetts: Sinauer Associates. pp. 132–133. ISBN   978-1-60535-380-7.
  17. ↑ Kihara H, Yamamoto Y, Sato T, Yamazaki Y, Sakakibara S, Yamaguchi S, et al. (2004). "Amino Acids". Kirk-Othmer Encyclopedia of Chemical Technology. John Wiley & Sons. doi:10.1002/0471238961.0113091411090801.a01.pub2 (inactive July 8, 2025).{{cite encyclopedia}}: CS1 maint: DOI inactive as of July 2025 (link)
  18. ↑ Drauz K, Gröger H, Han O (2000). "Amino Acids". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a02_057. ISBN   3-527-30673-0.
  19. ↑ Haynes WM, ed. (2017). CRC Handbook of Chemistry and Physics (97th ed.). Boca Raton: CRC Press. p. 5-92. ISBN   978-1-4987-5429-3.
  20. ↑ Alves A, Bassot A, Bulteau AL, Pirola L, Morio B (June 2019). "Glycine Metabolism and Its Alterations in Obesity and Metabolic Diseases". Nutrients. 11 (6): 1356. doi: 10.3390/nu11061356 . PMC   6627940 . PMID   31208147.
  21. ↑ Plimmer RH (1912) [1908]. Plimmer RH, Hopkins F (eds.). The chemical composition of the proteins. Monographs on biochemistry. Vol. Part I. Analysis (2nd ed.). London: Longmans, Green and Co. p. 82. Retrieved January 18, 2010.
  22. ↑ Braconnot H (1820). "Sur la conversion des matières animales en nouvelles substances par le moyen de l'acide sulfurique" [On the conversion of animal materials into new substances by means of sulfuric acid]. Annales de Chimie et de Physique. 2nd series (in French). 13: 113–125 [114].
  23. ↑ MacKenzie C (1822). One Thousand Experiments in Chemistry: With Illustrations of Natural Phenomena; and Practical Observations on the Manufacturing and Chemical Processes at Present Pursued in the Successful Cultivation of the Useful Arts ... Sir R. Phillips and Company. p.  557.
  24. ↑ Boussingault (1838). "Sur la composition du sucre de gélatine et de l'acide nitro-saccharique de Braconnot" [On the composition of sugar of gelatine and of nitro-glucaric acid of Braconnot]. Comptes Rendus (in French). 7: 493–495.
  25. ↑ Horsford EN (1847). "Glycocoll (gelatine sugar) and some of its products of decomposition". The American Journal of Science and Arts. 2nd series. 3: 369–381.
  26. ↑ Ihde AJ (1984). The Development of Modern Chemistry. Courier Corporation. p. 167. ISBN   978-0-486-64235-2.
  27. ↑ Berzelius J (1848). Jahres-Bericht über die Fortschritte der Chemie und Mineralogie (Annual Report on the Progress of Chemistry and Mineralogy). Vol. 47. Tübigen, (Germany): Laupp. p. 654. From p. 654: "Er hat dem Leimzucker als Basis den Namen Glycocoll gegeben. ... Glycin genannt werden, und diesen Namen werde ich anwenden." (He [i.e., the American scientist Eben Norton Horsford, then a student of the German chemist Justus von Liebig] gave the name "glycocoll" to Leimzucker [sugar of gelatine], a base. This name is not euphonious and has besides the flaw that it clashes with the names of the rest of the bases. It is compounded from γλυχυς (sweet) and χολλα (animal glue). Since this organic base is the only [one] which tastes sweet, then it can much more briefly be named "glycine", and I will use this name.)
  28. ↑ Nye MJ (1999). Before Big Science: The Pursuit of Modern Chemistry and Physics, 1800–1940. Harvard University Press. p. 141. ISBN   978-0-674-06382-2.
  29. ↑ "glycine". Oxford Dictionaries. Archived from the original on November 13, 2014. Retrieved December 6, 2015.
  30. ↑ Cahours A (1858). "Recherches sur les acides amidés" [Investigations into aminated acids]. Comptes Rendus (in French). 46: 1044–1047.
  31. ↑ Okafor N (2016). Modern Industrial Microbiology and Biotechnology. CRC Press. p. 385. ISBN   978-1-4398-4323-9.
  32. ↑ Ingersoll AW, Babcock SH (1932). "Hippuric acid". Organic Syntheses . 12: 40; Collected Volumes, vol. 2, p. 328.
  33. ↑ Kirk-Othmer Food and Feed Technology, 2 Volume Set. John Wiley & Sons. 2007. p. 38. ISBN   978-0-470-17448-7.
  34. ↑ "Glycine Conference (prelim)". USITC. Archived from the original on February 22, 2012. Retrieved June 13, 2014.
  35. 1 2 3 Drauz K, Grayson I, Kleemann A, Krimmer HP, Leuchtenberger W, Weckbecker C (2007). "Amino Acids". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a02_057.pub2. ISBN   978-3-527-30385-4.
  36. ↑ Hart JR (2005). "Ethylenediaminetetraacetic Acid and Related Chelating Agents". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a10_095. ISBN   978-3-527-30673-2.
  37. ↑ Tomiyasu H, Gordon G (April 1976). "Ring closure in the reaction of metal chelates. Formation of the bidentate oxovanadium(IV)-glycine complex". Inorganic Chemistry. 15 (4): 870–874. doi:10.1021/ic50158a027.
  38. ↑ Lutz OM, Messner CB, Hofer TS, Glätzle M, Huck CW, Bonn GK, et al. (May 2013). "Combined Ab Initio Computational and Infrared Spectroscopic Study of the cis- and trans-Bis(glycinato)copper(II) Complexes in Aqueous Environment". The Journal of Physical Chemistry Letters. 4 (9): 1502–1506. doi:10.1021/jz400288c. PMID   26282305.
  39. ↑ D'Angelo P, Bottari E, Festa MR, Nolting HF, Pavel NV (April 1998). "X-ray Absorption Study of Copper(II)−Glycinate Complexes in Aqueous Solution". The Journal of Physical Chemistry B. 102 (17): 3114–3122. doi:10.1021/jp973476m.
  40. ↑ Ingersoll AW, Babcock SH (1932). "Hippuric Acid". Org. Synth. 12: 40. doi:10.15227/orgsyn.012.0040.
  41. ↑ Herbst RM, Shemin D (1939). "Acetylglycine". Org. Synth. 19: 4. doi:10.15227/orgsyn.019.0004.
  42. ↑ Van Dornshuld E, Vergenz RA, Tschumper GS (July 2014). "Peptide bond formation via glycine condensation in the gas phase". The Journal of Physical Chemistry B. 118 (29): 8583–8590. doi:10.1021/jp504924c. PMID   24992687.
  43. ↑ Leng L, Yang L, Zu H, Yang J, Ai Z, Zhang W, et al. (November 2023). "Insights into glycine pyrolysis mechanisms: Integrated experimental and molecular dynamics/DFT simulation studies". Fuel. 351 128949. Bibcode:2023Fuel..35128949L. doi:10.1016/j.fuel.2023.128949.
  44. ↑ Meléndez-Hevia E, De Paz-Lugo P, Cornish-Bowden A, Cárdenas ML (December 2009). "A weak link in metabolism: the metabolic capacity for glycine biosynthesis does not satisfy the need for collagen synthesis". Journal of Biosciences. 34 (6): 853–872. doi:10.1007/s12038-009-0100-9. ISSN   0973-7138. PMID   20093739.
  45. 1 2 3 4 5 6 7 Nelson DL, Cox MM (2005). Principles of Biochemistry (4th ed.). New York: W. H. Freeman. pp. 127, 675–77, 844, 854. ISBN   0-7167-4339-6.
  46. ↑ Kwon YK, Higgins MB, Rabinowitz JD (August 2010). "Antifolate-induced depletion of intracellular glycine and purines inhibits thymineless death in E. coli". ACS Chemical Biology. 5 (8): 787–795. doi:10.1021/cb100096f. PMC   2945287 . PMID   20553049.
  47. ↑ Wang W, Wu Z, Dai Z, Yang Y, Wang J, Wu G (September 2013). "Glycine metabolism in animals and humans: implications for nutrition and health". Amino Acids. 45 (3): 463–477. doi:10.1007/s00726-013-1493-1. PMID   23615880. S2CID   7577607.
  48. 1 2 Hahn RG (1993). "Dose-dependent half-life of glycine". Urological Research. 21 (4): 289–291. doi:10.1007/BF00307714. PMID   8212419. S2CID   25138444.
  49. ↑ Szpak P (2011). "Fish bone chemistry and ultrastructure: implications for taphonomy and stable isotope analysis". Journal of Archaeological Science . 38 (12): 3358–3372. Bibcode:2011JArSc..38.3358S. doi:10.1016/j.jas.2011.07.022.
  50. ↑ Liu Y, Zhang J (October 2000). "Recent development in NMDA receptors". Chinese Medical Journal. 113 (10): 948–56. PMID   11775847.
  51. ↑ "Safety (MSDS) data for glycine". The Physical and Theoretical Chemistry Laboratory Oxford University. 2005. Archived from the original on October 20, 2007. Retrieved November 1, 2006.
  52. ↑ van der Sluis R, Badenhorst CP, Erasmus E, van Dyk E, van der Westhuizen FH, van Dijk AA (October 2015). "Conservation of the coding regions of the glycine N-acyltransferase gene further suggests that glycine conjugation is an essential detoxification pathway". Gene. 571 (1): 126–134. doi:10.1016/j.gene.2015.06.081. PMID   26149650.
  53. ↑ Badenhorst CP, Erasmus E, van der Sluis R, Nortje C, van Dijk AA (August 2014). "A new perspective on the importance of glycine conjugation in the metabolism of aromatic acids". Drug Metabolism Reviews. 46 (3): 343–361. doi:10.3109/03602532.2014.908903. PMID   24754494.
  54. ↑ Di Ciaula A, Garruti G, Lunardi Baccetto R, Molina-Molina E, Bonfrate L, Wang DQ, et al. (November 2017). "Bile Acid Physiology". Annals of Hepatology. 16 (Suppl. 1: s3–105): s4 –s14. doi: 10.5604/01.3001.0010.5493 . hdl: 11586/203563 . PMID   29080336.
  55. ↑ Nair B (January 2001). "Final report on the safety assessment of Benzyl Alcohol, Benzoic Acid, and Sodium Benzoate". International Journal of Toxicology. 20 Suppl 3 (3_suppl): 23–50. doi:10.1080/10915810152630729. PMID   11766131.
  56. ↑ "butyrate-CoA ligase". BRENDA. Technische Universität Braunschweig. Retrieved May 7, 2014. Substrate/Product
  57. ↑ "glycine N-acyltransferase". BRENDA. Technische Universität Braunschweig. Retrieved May 7, 2014. Substrate/Product
  58. ↑ "Glycine From Japan and Korea" (PDF). U.S. International Trade Commission. January 2008. Archived (PDF) from the original on June 6, 2010. Retrieved June 13, 2014.
  59. ↑ Casari BM, Mahmoudkhani AH, Langer V (2004). "A Redetermination of cis-Aquabis(glycinato-κ2N,O)copper(II)". Acta Crystallogr. E. 60 (12): m1949 –m1951. doi:10.1107/S1600536804030041.
  60. ↑ "eCFR :: 21 CFR 170.50 – Glycine (aminoacetic acid) in food for human consumption". ecfr.gov. Retrieved October 24, 2022.
  61. ↑ "eCFR :: 21 CFR 172.812 – Glycine". ecfr.gov. Retrieved July 6, 2024.
  62. 1 2 Johnson AA, Cuellar TL (June 2023). "Glycine and aging: Evidence and mechanisms". Ageing Research Reviews. 87 101922. doi: 10.1016/j.arr.2023.101922 . PMID   37004845.
  63. ↑ Soh J, Raventhiran S, Lee JH, Lim ZX, Goh J, Kennedy BK, et al. (February 2024). "The effect of glycine administration on the characteristics of physiological systems in human adults: A systematic review". GeroScience. 46 (1): 219–239. doi:10.1007/s11357-023-00970-8. PMC   10828290 . PMID   37851316.
  64. ↑ Stahl SS, Alsters PL (2016). Liquid Phase Aerobic Oxidation Catalysis: Industrial Applications and Academic Perspectives. John Wiley & Sons. p. 268. ISBN   978-3-527-69015-2.
  65. ↑ Wu G, Schumacher DP, Tormos W, Clark JE, Murphy BL (May 2, 1997). "An Improved Industrial Synthesis of Florfenicol plus an Enantioselective Total Synthesis of Thiamphenicol and Florfenicol". The Journal of Organic Chemistry. 62 (9). American Chemical Society: 2996–2998. doi:10.1021/jo961479+. PMID   11671665 . Retrieved May 31, 2025.
  66. ↑ Schägger H (May 12, 2006). "Tricine-SDS-PAGE". Nature Protocols. 1 (1): 16–22. doi:10.1038/nprot.2006.4. PMID   17406207.
  67. ↑ Legocki RP, Verma DP (March 1981). "Multiple immunoreplica Technique: screening for specific proteins with a series of different antibodies using one polyacrylamide gel". Analytical Biochemistry. 111 (2): 385–392. doi:10.1016/0003-2697(81)90577-7. PMID   6166216.
  68. ↑ Kvenvolden K, Lawless J, Pering K, Peterson E, Flores J, Ponnamperuma C, et al. (December 1970). "Evidence for extraterrestrial amino-acids and hydrocarbons in the Murchison meteorite". Nature. 228 (5275): 923–926. Bibcode:1970Natur.228..923K. doi:10.1038/228923a0. PMID   5482102. S2CID   4147981.
  69. ↑ "Building block of life found on comet". Thomson Reuters 2009. August 18, 2009. Retrieved August 18, 2009.
  70. ↑ European Space Agency (May 27, 2016). "Rosetta's comet contains ingredients for life" . Retrieved June 5, 2016.
  71. ↑ Ramos MF, Silva NA, Muga NJ, Pinto AN (February 2020). "Reversal operator to compensate polarization random drifts in quantum communications". Optics Express. 28 (4): 5035–5049. arXiv: astro-ph/0410335 . Bibcode:2005ApJ...619..914S. doi:10.1086/426677. PMID   32121732. S2CID   16286204.
  72. ↑ Trifonov EN (December 2000). "Consensus temporal order of amino acids and evolution of the triplet code". Gene. 261 (1): 139–151. doi:10.1016/S0378-1119(00)00476-5. PMID   11164045.
  73. ↑ Higgs PG, Pudritz RE (June 2009). "A thermodynamic basis for prebiotic amino acid synthesis and the nature of the first genetic code". Astrobiology. 9 (5): 483–490. arXiv: 0904.0402 . Bibcode:2009AsBio...9..483H. doi:10.1089/ast.2008.0280. PMID   19566427. S2CID   9039622 .
  74. ↑ Chaliotis A, Vlastaridis P, Mossialos D, Ibba M, Becker HD, Stathopoulos C, et al. (February 2017). "The complex evolutionary history of aminoacyl-tRNA synthetases". Nucleic Acids Research. 45 (3): 1059–1068. doi: 10.1093/nar/gkw1182 . PMC   5388404 . PMID   28180287.
  75. 1 2 Ntountoumi C, Vlastaridis P, Mossialos D, Stathopoulos C, Iliopoulos I, Promponas V, et al. (November 2019). "Low complexity regions in the proteins of prokaryotes perform important functional roles and are highly conserved". Nucleic Acids Research. 47 (19): 9998–10009. doi: 10.1093/nar/gkz730 . PMC   6821194 . PMID   31504783.
  76. ↑ "FoodData Central Search Results for 'Glycine (g)'". fdc.nal.usda.gov. Retrieved May 26, 2024.

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