Difference between revisions of "Guanine" - New World Encyclopedia

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{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
 
{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
 
! {{chembox header}} | Guanine <!-- replace if not identical with the article name —>
 
! {{chembox header}} | Guanine <!-- replace if not identical with the article name —>
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! {{chembox header}} | General
 
! {{chembox header}} | General
 
|-  
 
|-  
−
| [[IUPAC nomenclature|Systematic name]]*
+
| [[IUPAC nomenclature|Systematic name]]
 
| 2-amino-1''H''-purin-6(9''H'')-one
 
| 2-amino-1''H''-purin-6(9''H'')-one
 
|-
 
|-
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| 2-amino-6-oxo-purine,<br />2-aminohypoxanthine,<br />Guanine
 
| 2-amino-6-oxo-purine,<br />2-aminohypoxanthine,<br />Guanine
 
|-
 
|-
−
| [[Chemical formula|Molecular formula]]*
+
| [[Chemical formula|Molecular formula]]
 
| C<sub>5</sub>H<sub>5</sub>N<sub>5</sub>O
 
| C<sub>5</sub>H<sub>5</sub>N<sub>5</sub>O
 
|-
 
|-
−
| [[Simplified molecular input line entry specification|SMILES]]* <!-- mostly for organic compounds, omit otherwise —>
+
| [[Simplified molecular input line entry specification|SMILES]] <!-- mostly for organic compounds, omit otherwise —>
 
| NC(NC1=O)=NC2=C1N=CN2
 
| NC(NC1=O)=NC2=C1N=CN2
 
|-
 
|-
−
| [[Molar mass]]*
+
| [[Molar mass]]
 
| 151.1261 g/mol
 
| 151.1261 g/mol
 
|-
 
|-
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| White amorphous solid.
 
| White amorphous solid.
 
|-
 
|-
−
| [[CAS registry number|CAS number]]*
+
| [[CAS registry number|CAS number]]
 
| {{CASREF|CAS=73-40-5}}
 
| {{CASREF|CAS=73-40-5}}
 
|-
 
|-
 
! {{chembox header}} | Properties
 
! {{chembox header}} | Properties
 
|-
 
|-
−
| [[Density]]* and [[Phase (matter)|phase]]
+
| [[Density]] and [[Phase (matter)|phase]]
 
| ? g/cm<sup>3</sup>, solid.
 
| ? g/cm<sup>3</sup>, solid.
 
|-
 
|-
−
| [[Solubility]] in [[Water (molecule)|water]]*
+
| [[Solubility]] in [[Water (molecule)|water]]
 
| Insoluable.
 
| Insoluable.
 
|-
 
|-
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<!-- | solubility info on other solvents —>
 
<!-- | solubility info on other solvents —>
 
<!-- |- —>
 
<!-- |- —>
−
| [[Melting point]]*
+
| [[Melting point]]
 
| 360°C (633.15 K) ''deco.''
 
| 360°C (633.15 K) ''deco.''
 
|-
 
|-
−
| [[Boiling point]]*
+
| [[Boiling point]]
 
| Sublimes.
 
| Sublimes.
 
|-
 
|-
 
! {{chembox header}} | Structure
 
! {{chembox header}} | Structure
 
|-
 
|-
−
| [[Crystal structure]]* <!-- omit if not a solid —>
+
| [[Crystal structure]] <!-- omit if not a solid —>
−
| ? <!-- e.g. [[triclinic]], [[monoclinic]], [[orthorhombic]], [[hexagonal]], [[rhombohedral|trigonal]], [[tetragonal]], [[cubic]], and mention "close packed" or similar. You may also cite what class it belongs to, e.g. [[Cadmium chloride#Crystal structure|CdCl<sub>2</sub>]] —>
+
| ? <!-- e.g. [[triclinic]], [[monoclinic]], [[orthorhombic]], [[hexagonal]], [[rhombohedral|trigonal]], [[tetragonal]], [[cubic]], and mention "close packed" or similar. You may also cite what class it belongs to, e.g. [[Cadmium chloride#Crystal structure|CdCl<sub>2</sub>]] —>
 
|-
 
|-
−
| [[Dipole#Molecular dipoles|Dipole moment]]*
+
| [[Dipole#Molecular dipoles|Dipole moment]]
 
| ? [[Debye|D]]
 
| ? [[Debye|D]]
 
|-
 
|-
−
! {{chembox header}} | Hazards <!-- Summary only- MSDS entry provides more complete information —>
+
! {{chembox header}} | Hazards <!-- Summary only- MSDS entry provides more complete information —>
 
|-
 
|-
−
| [[Material safety data sheet|MSDS]]*
+
| [[Material safety data sheet|MSDS]]
−
| [[Guanine (data page)#Material Safety Data Sheet|External MSDS]]* <!-- please replace with proper link—>
+
| [[Guanine (data page)#Material Safety Data Sheet|External MSDS]] <!-- please replace with proper link—>
 
|-
 
|-
−
| Main [[Worker safety and health|hazard]]*s
+
| Main [[Worker safety and health|hazard]]s
 
| Irritant.
 
| Irritant.
 
|-
 
|-
−
| [[NFPA 704]]*
+
| [[NFPA 704]]
 
| {{NFPA 704 | Health=1 | Flammability=1 }}
 
| {{NFPA 704 | Health=1 | Flammability=1 }}
 
|-
 
|-
−
| [[Flash point]]*
+
| [[Flash point]]
 
| Non-flammable.
 
| Non-flammable.
 
|-
 
|-
−
| [[Risk and Safety Statements|R/S statement]]*
+
| [[Risk and Safety Statements|R/S statement]]
−
| [[List of R-phrases|R]]*: {{R36}}, {{R37}}, {{R38}}. <br /> [[List of S-phrases|S]]*: {{R24/25}}, {{R26}}, {{R36}}.
+
| [[List of R-phrases|R]]: {{R36}}, {{R37}}, {{R38}}. <br /> [[List of S-phrases|S]]: {{R24/25}}, {{R26}}, {{R36}}.
 
|-
 
|-
−
| [[RTECS]]* number
+
| [[RTECS]] number
 
| MF8260000
 
| MF8260000
 
|-
 
|-
−
! {{chembox header}} | [[Guanine (data page)|Supplementary data page]]*
+
! {{chembox header}} | [[Guanine (data page)|Supplementary data page]]
 
|-
 
|-
−
| [[Guanine (data page)#Structure and properties|Structure and<br />properties]]*
+
| [[Guanine (data page)#Structure and properties|Structure and<br />properties]]  
−
| [[Refractive index|''n'']]*, [[Dielectric constant|ε<sub>r</sub>]]*, etc.  
+
| [[Refractive index|''n'']], [[Dielectric constant|ε<sub>r</sub>]], etc.  
 
|-
 
|-
−
| [[Guanine (data page)#Thermodynamic properties|Thermodynamic<br />data]]*
+
| [[Guanine (data page)#Thermodynamic properties|Thermodynamic<br />data]]  
 
| Phase behaviour<br />Solid, liquid, gas  
 
| Phase behaviour<br />Solid, liquid, gas  
 
|-
 
|-
−
| [[Guanine (data page)#Spectral data|Spectral data]]*
+
| [[Guanine (data page)#Spectral data|Spectral data]]
−
| [[UV/VIS spectroscopy|UV]]*, [[Infrared spectroscopy|IR]]*, [[nuclear magnetic resonance spectroscopy|NMR]]*, [[Mass spectrometry|MS]]
+
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
 
|-
 
|-
 
! {{chembox header}} | Related compounds
 
! {{chembox header}} | Related compounds
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| [[cytosine|Cytosine]],<br />[[adenine|Adenine]],<br />[[thymine|Thymine]],<br />[[uracil|Uracil]]
 
| [[cytosine|Cytosine]],<br />[[adenine|Adenine]],<br />[[thymine|Thymine]],<br />[[uracil|Uracil]]
 
|-
 
|-
−
| {{chembox header}} | <small>Except where noted otherwise, data are given for<br /> materials in their [[standard state|standard state (at 25°C, 100 kPa)]]*<br /></small>
+
| {{chembox header}} | <small>Except where noted otherwise, data are given for<br /> materials in their [[standard state|standard state (at 25°C, 100 kPa)]]<br /></small>
 
|-
 
|-
 
|}
 
|}
−
'''Guanine''' is one of the five main [[nucleotide#Chemical structure and nomenclature|nucleobase]]s found in the [[nucleic acid]]s [[DNA]] and [[RNA]]; the others being [[adenine]], [[cytosine]], [[thymine]], and [[uracil]]. With the formula C<sub>5</sub>H<sub>5</sub>N<sub>5</sub>O, guanine is a [[purine]] derivative, consisting of a fused [[pyrimidine]]-imidazole ring system with conjugated double bonds. Being unsaturated, the bicyclic molecule is planar.  The guanine [[nucleotide#Chemical structure and nomenclature|nucleoside]] is called guanosine.
+
'''Guanine''', a two-ring molecular structure, is one of the five defining components or [[nucleotide#Chemical structure and nomenclature|nucleobase]]s found in the [[nucleic acid]]s [[DNA]] and [[RNA]]; the others being [[adenine]], [[cytosine]], [[thymine]], and [[uracil]]. Guanine and adenine are derived from the two-ring parent molecule [[purine]], and cytosine, thymine, and uracil are derived from the one-ring parent molecule [[pyrimidine]].
  
−
In DNA, adenine and guanine, which are purine derivatives, form hydrogen bonds with their complementary pyrimidine derivatives, thymine and cytosine. In RNA, the complement of adenine is uracil instead of thymine.
+
Guanine (C<sub>5</sub>H<sub>5</sub>N<sub>5</sub>O), comprises a six-carbon pyrimidine ring fused with a five-carbon imidazole ring to form a system stabilized by conjugated [[chemical bond|double bonds]] (the positions of the double bonds shift around the ring). Being unsaturated, the bicyclic [[molecule]] is planar. The guanine [[nucleotide#Chemical structure and nomenclature|nucleoside]] (guanine bonded with a five-carbon sugar) is called guanosine and lacks only a phosphate to form a [[nucleotide]].
  
−
==Basic principles==
+
In DNA, guanine and adenine form [[chemical bond#hydrogen bond|hydrogen bonds]] with their complementary pyrimidine derivatives, cytosine and thymine. In RNA, the complement of adenine is uracil instead of thymine. Thus, guanine, along with adenine and cytosine, is present in both DNA and RNA, whereas thymine is usually seen only in DNA and uracil only in RNA.  
−
Guanine, along with adenine and cytosine, is present in both DNA and RNA, whereas thymine is usually seen only in DNA and uracil only in RNA. Guanine has two tautomeric forms, the [[keto-enol tautomerism|keto form and enol form]].
+
 
−
It binds to cytosine through three [[hydrogen bond]]s.  In cytosine, the amino group acts as the hydrogen donor and the C-2 carbonyl and the N-3 amine as the hydrogen-bond  acceptors.  Guanine has a group at C-6 that acts as the hydrogen acceptor, while the group at N-1 and the amino group at C-2 acts as the hydrogen donors.
+
The ubiquitousness of guanine, which plays a central role in the the DNA of all living [[organism]]s and even in RNA [[virus]]es is evidence of the connectedness and unity of all [[life]].  
 +
 
 +
==Basic properties==
 
{| align="center"
 
{| align="center"
 
|-
 
|-
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|}
 
|}
  
−
==Isolation, background, & some chemistry==
+
Guanine binds to cytosine through three hydrogen bonds. In cytosine, the amino group acts as the hydrogen donor and the C-2 carbonyl and the N-3 amine as the [[hydrogen]]-bond acceptors. Guanine has a group at C-6 that acts as the hydrogen acceptor, while the group at N-1 and the amino group at C-2 acts as the hydrogen donors.
−
The first isolation of guanine was reported in 1844 from the excreta of sea birds, known as guano, which was used as a source of fertilizer. About fifty years Fischer determined the structure and also showed that uric acid can be converted to guanine. The first complete synthesis was done by Traube and remains among the best large-scale preparations.
+
 
 +
Guanine has two tautomeric forms: the keto form (characterized by an attached OH group) and the enol form (characterized by an attached CH2 group).
 +
 
 +
Guanine can be hydrolyzed with strong acid at 180°C to glycine, ammonia, [[carbon dioxide]], and [[carbon monoxide]]. Guanine oxidizes more readily than [[adenine]], the other purine-derivative base in DNA and RNA. Its high [[melting point]] of 350°C reflects the strong intermolecular hydrogen bonding between the oxo and amino groups in the molecules in the crystal. Because of this intermolecular bonding, guanine is relatively insoluble in [[water]], although it is soluble in dilute [[acid]]s and [[base]]s.
  
−
Guanine can be hydrolyzed with strong acid to glycine, ammonia, carbon dioxide, and carbon monoxide at 180°C. Guanine oxidizes more readily than adenine, the other purine-derivative base in DNA and RNA. Its  high melting point of 350°C reflects the intermolecular hydrogen bonding between the oxo and amino groups in the molecules in the crystal.  Because of this intermolecular bonding, guanine is relatively insoluble in water, although it is soluble in dilute acids and bases.
+
==History==
 +
The first isolation of guanine was reported in 1844 from sea bird excreta, which is known as guano and was used as a source of fertilizer. About fifty years later, Fischer determined guanine's structure and showed that [[uric acid]] can be converted to guanine. The first complete synthesis of guanine was done by Traube and remains among the best large-scale preparations.
  
−
==Syntheses==
+
==Synthesis==
−
Trace amounts of guanine form by the polymerization of ammonium cyanide (NH<sub>4</sub>CN). Two experiments conducted by Levy et al., showed that heating 10 M NH<sub>4</sub>CN at 80°C for 24 hours gave a yield of 0.0007% while using 0.1 M NH<sub>4</sub>CN frozen at -20°C for 25 years gave a 0.0035% yield. These results indicate guanine could arise in frozen regions of the primitive earth. In 1984, Yuasa reported a 0.00017% yield of guanine after the electrical discharge of NH<sub>3</sub>, CH<sub>4</sub>, C<sub>2</sub>H<sub>6</sub>, and 50 mL of water, followed by a subsequent acid hydrolysis. However, it is unknown if the presence of guanine was not simply resulted from a contaminant of the reaction.
+
Trace amounts of guanine form by the polymerization of ammonium cyanide (NH<sub>4</sub>CN). Two experiments conducted by Levy et al., showed that heating ten mole NH<sub>4</sub>CN at 80°C for 24 hours gave a yield of 0.0007 percent while using 0.1 mole NH<sub>4</sub>CN frozen at -20°C for 25 years gave a 0.0035 percent yield (Levy et al. 1999). These results indicate guanine could arise in frozen regions of the primitive earth. In 1984, Yuasa reported a 0.00017 percent yield of guanine after the electrical discharge of NH<sub>3</sub>, CH<sub>4</sub>, C<sub>2</sub>H<sub>6</sub>, and 50 mL of [[water]], followed by a subsequent acid hydrolysis (Miyakawa et al. 2000). However, it is unknown if the presence of guanine was not simply a contaminant of the reaction.
 
:5NH<sub>3</sub> + CH<sub>4</sub> + 2C<sub>2</sub>H<sub>6</sub> + H<sub>2</sub>O → C<sub>5</sub>H<sub>8</sub>N<sub>5</sub>O (guanine) + (25/2)H<sub>2</sub>
 
:5NH<sub>3</sub> + CH<sub>4</sub> + 2C<sub>2</sub>H<sub>6</sub> + H<sub>2</sub>O → C<sub>5</sub>H<sub>8</sub>N<sub>5</sub>O (guanine) + (25/2)H<sub>2</sub>
  
−
A Fischer-Tropsch synthesis can also be used to form guanine, along with adenine, uracil and thymine. Heating an equimolar gas mixture of CO, H<sub>2</sub>, and NH<sub>3</sub> to 700 °C for 0.24 to 0.4 hours, followed by quick cooling and then sustainted reheating to 100-200°C for 16-44 hours with an alumina catalyst yielded guanine and uracil:
+
A Fischer-Tropsch synthesis can also be used to form guanine, along with [[adenine]], [[uracil]], and [[thymine]]. Heating an equimolar gas mixture of CO, H<sub>2</sub>, and NH<sub>3</sub> to 700 °C for 0.24 to 0.4 hours, followed by quick cooling, and then sustained reheating to 100-200°C for 16-44 hours with an alumina catalyst yielded guanine and uracil:
 
:5CO + (1/2)H<sub>2</sub> + 5NH<sub>3</sub> → C<sub>5</sub>H<sub>8</sub>N<sub>5</sub>O (guanine) + 4H<sub>2</sub>O
 
:5CO + (1/2)H<sub>2</sub> + 5NH<sub>3</sub> → C<sub>5</sub>H<sub>8</sub>N<sub>5</sub>O (guanine) + 4H<sub>2</sub>O
  
Line 126: Line 133:
 
[[Image:Guaninesynth.png|600px]]
 
[[Image:Guaninesynth.png|600px]]
  
−
==Other uses==
+
==Commercial uses==
−
In 1656 in Paris, François Jaquin (a rosary maker) extracted from scales of some fishes the so called pearl essence, crystalline guanine forming [[G-quadruplex]]es: in cosmetic industry, crystalline guanine is used as an additive to various products (e.g., [[shampoo]]s), where it provides the pearly [[iridescence|iridescent]] effect. It is also used in metallic paints and simulated pearls and plastics. It provides shimmering lustre to eye shadow and [[nail polish]]. Guanine crystals are rhombic platelets composed of multiple, transparent layers but they have a high index of refraction that partially reflects and transmits light from layer to layer thus producing a pearly luster. It can be applied by spray, painting or dipping. It may irritate eyes. Its alternatives are [[mica]], synthetic [[pearl]], and [[aluminium]] and [[bronze]] particles.
+
In 1656 in [[Paris]], François Jaquin (a rosary maker) extracted from scales of some [[fish]]es the so-called "pearl essence"&mdash;crystalline guanine forming G-quadruplexes. Guanine crystals are rhombic platelets composed of multiple, transparent layers but they have a high index of refraction that partially reflects and transmits [[light]] from layer to layer, thus producing a pearly luster. In the cosmetics industry, crystalline guanine is used as an additive to various products (e.g., shampoos), where it provides the pearly iridescent effect. It is also used in metallic paints and simulated pearls and plastics. Crystalline guanine provides shimmering luster to eye shadow and nail polish. It can be applied by spray, painting, or dipping, but it may irritate eyes. Alternatives include mica, synthetic pearl, and [[aluminium]] and [[bronze]] particles.
  
 
==References==
 
==References==
−
1. Miyakawa, S., Murasawa, K., Kobayashi, K., Sawaoka, AB.  "Abiotic synthesis of guanine with high-temperature plasma." Orig Life Evol Biosph. 30(6): 557-66, Dec. 2000.
 
−
<br\>
 
−
2. Horton, H.R., Moran, L.A., Ochs, R.S., Rawn, J.D., Scrimgeour, K.G.  "Principles of Biochemistry."  Prentice Hall (New Jersey).  3rd Edition, 2002.
 
−
<br\>
 
−
3.  Lister, J.H.  "Part II Purines."  The Chemistry of Heterocyclic Compounds.  Wiley-Interscience (New York).  1971.
 
  
−
==External links==
+
* Horton, H. R., L. A. Moran, R. S. Ochs, J. D. Rawn, and K. G. Scrimgeour. ''Principles of Biochemistry''. New Jersey: Prentice Hall, 2000.
−
*[http://www.compchemwiki.org/index.php?title=Guanine Computational Chemistry Wiki]
+
* Levy, M., S. L. Miller, and John Oró. “Production of guanine from NH4CN polymerizations.” '' Journal of Molecular Evolution''. 49(2):165-168, 1999.
−
*[http://www.chemicalland21.com/lifescience/phar/GUANINE.htm Good Guanine reference]
+
* Lister, J. H. “Part II, Purines.” In D. J. Brown, ed., ''The Chemistry of Heterocyclic Compounds''. New York: Wiley-Interscience, 1971.
 +
* Miyakawa, S., K. Murasawa, K. Kobayashi, and A. B. Sawaoka. “Abiotic synthesis of guanine with high-temperature plasma.” ''Orig Life Evol Biosph.'' 30(6): 557-66, 2000.  
  
 +
  
 
{{Nucleic acids}}
 
{{Nucleic acids}}
  
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+
{{credit|95526522}}
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[[Category:Life sciences]]
 
[[Category:Life sciences]]
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[[Category:Molecular biology]]
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{{credit|95526522}}
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[[Category:Genetics]]

Latest revision as of 14:09, 29 August 2008


Guanine
Guanine
General
Systematic name 2-amino-1H-purin-6(9H)-one
Other names 2-amino-6-oxo-purine,
2-aminohypoxanthine,
Guanine
Molecular formula C5H5N5O
SMILES NC(NC1=O)=NC2=C1N=CN2
Molar mass 151.1261 g/mol
Appearance White amorphous solid.
CAS number [73-40-5] [1]
Properties
Density and phase ? g/cm3, solid.
Solubility in water Insoluable.
Melting point 360°C (633.15 K) deco.
Boiling point Sublimes.
Structure
Crystal structure ?
Dipole moment ? D
Hazards
MSDS External MSDS
Main hazards Irritant.
NFPA 704

NFPA 704.svg

1
1
0
 
Flash point Non-flammable.
R/S statement R: R36, R37, R38.
S: R24/25, R26, R36.
RTECS number MF8260000
Supplementary data page
Structure and
properties 		n, εr, etc.
Thermodynamic
data 		Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Related compounds
Other anions ?
Other cations ?
Related compounds Cytosine,
Adenine,
Thymine,
Uracil
Except where noted otherwise, data are given for
materials in their standard state (at 25°C, 100 kPa)

Guanine, a two-ring molecular structure, is one of the five defining components or nucleobases found in the nucleic acids DNA and RNA; the others being adenine, cytosine, thymine, and uracil. Guanine and adenine are derived from the two-ring parent molecule purine, and cytosine, thymine, and uracil are derived from the one-ring parent molecule pyrimidine.

Guanine (C5H5N5O), comprises a six-carbon pyrimidine ring fused with a five-carbon imidazole ring to form a system stabilized by conjugated double bonds (the positions of the double bonds shift around the ring). Being unsaturated, the bicyclic molecule is planar. The guanine nucleoside (guanine bonded with a five-carbon sugar) is called guanosine and lacks only a phosphate to form a nucleotide.

In DNA, guanine and adenine form hydrogen bonds with their complementary pyrimidine derivatives, cytosine and thymine. In RNA, the complement of adenine is uracil instead of thymine. Thus, guanine, along with adenine and cytosine, is present in both DNA and RNA, whereas thymine is usually seen only in DNA and uracil only in RNA.

The ubiquitousness of guanine, which plays a central role in the the DNA of all living organisms and even in RNA viruses is evidence of the connectedness and unity of all life.

Basic properties

Cytonum2.png Guannum2.png

Guanine binds to cytosine through three hydrogen bonds. In cytosine, the amino group acts as the hydrogen donor and the C-2 carbonyl and the N-3 amine as the hydrogen-bond acceptors. Guanine has a group at C-6 that acts as the hydrogen acceptor, while the group at N-1 and the amino group at C-2 acts as the hydrogen donors.

Guanine has two tautomeric forms: the keto form (characterized by an attached OH group) and the enol form (characterized by an attached CH2 group).

Guanine can be hydrolyzed with strong acid at 180°C to glycine, ammonia, carbon dioxide, and carbon monoxide. Guanine oxidizes more readily than adenine, the other purine-derivative base in DNA and RNA. Its high melting point of 350°C reflects the strong intermolecular hydrogen bonding between the oxo and amino groups in the molecules in the crystal. Because of this intermolecular bonding, guanine is relatively insoluble in water, although it is soluble in dilute acids and bases.

History

The first isolation of guanine was reported in 1844 from sea bird excreta, which is known as guano and was used as a source of fertilizer. About fifty years later, Fischer determined guanine's structure and showed that uric acid can be converted to guanine. The first complete synthesis of guanine was done by Traube and remains among the best large-scale preparations.

Synthesis

Trace amounts of guanine form by the polymerization of ammonium cyanide (NH4CN). Two experiments conducted by Levy et al., showed that heating ten mole NH4CN at 80°C for 24 hours gave a yield of 0.0007 percent while using 0.1 mole NH4CN frozen at -20°C for 25 years gave a 0.0035 percent yield (Levy et al. 1999). These results indicate guanine could arise in frozen regions of the primitive earth. In 1984, Yuasa reported a 0.00017 percent yield of guanine after the electrical discharge of NH3, CH4, C2H6, and 50 mL of water, followed by a subsequent acid hydrolysis (Miyakawa et al. 2000). However, it is unknown if the presence of guanine was not simply a contaminant of the reaction.

5NH3 + CH4 + 2C2H6 + H2O → C5H8N5O (guanine) + (25/2)H2

A Fischer-Tropsch synthesis can also be used to form guanine, along with adenine, uracil, and thymine. Heating an equimolar gas mixture of CO, H2, and NH3 to 700 °C for 0.24 to 0.4 hours, followed by quick cooling, and then sustained reheating to 100-200°C for 16-44 hours with an alumina catalyst yielded guanine and uracil:

5CO + (1/2)H2 + 5NH3 → C5H8N5O (guanine) + 4H2O

Traube's synthesis involves heating 2,4,5-triamino-1,6-dihydro-6-oxypyrimidine (as the sulphate) with formic acid for several hours. Guaninesynth.png

Commercial uses

In 1656 in Paris, François Jaquin (a rosary maker) extracted from scales of some fishes the so-called "pearl essence"—crystalline guanine forming G-quadruplexes. Guanine crystals are rhombic platelets composed of multiple, transparent layers but they have a high index of refraction that partially reflects and transmits light from layer to layer, thus producing a pearly luster. In the cosmetics industry, crystalline guanine is used as an additive to various products (e.g., shampoos), where it provides the pearly iridescent effect. It is also used in metallic paints and simulated pearls and plastics. Crystalline guanine provides shimmering luster to eye shadow and nail polish. It can be applied by spray, painting, or dipping, but it may irritate eyes. Alternatives include mica, synthetic pearl, and aluminium and bronze particles.

References
ISBN links support NWE through referral fees

  • Horton, H. R., L. A. Moran, R. S. Ochs, J. D. Rawn, and K. G. Scrimgeour. Principles of Biochemistry. New Jersey: Prentice Hall, 2000.
  • Levy, M., S. L. Miller, and John Oró. “Production of guanine from NH4CN polymerizations.” Journal of Molecular Evolution. 49(2):165-168, 1999.
  • Lister, J. H. “Part II, Purines.” In D. J. Brown, ed., The Chemistry of Heterocyclic Compounds. New York: Wiley-Interscience, 1971.
  • Miyakawa, S., K. Murasawa, K. Kobayashi, and A. B. Sawaoka. “Abiotic synthesis of guanine with high-temperature plasma.” Orig Life Evol Biosph. 30(6): 557-66, 2000.


Nucleic acids edit
Nucleobases: Adenine - Thymine - Uracil - Guanine - Cytosine - Purine - Pyrimidine
Nucleosides: Adenosine - Uridine - Guanosine - Cytidine - Deoxyadenosine - Thymidine - Deoxyguanosine - Deoxycytidine
Nucleotides: AMP - UMP - GMP - CMP - ADP - UDP - GDP - CDP - ATP - UTP - GTP - CTP - cAMP - cGMP
Deoxynucleotides: dAMP - dTMP - dUMP - dGMP - dCMP - dADP - dTDP - dUDP - dGDP - dCDP - dATP - dTTP - dUTP - dGTP - dCTP
Nucleic acids: DNA - RNA - LNA - PNA - mRNA - ncRNA - miRNA - rRNA - siRNA - tRNA - mtDNA - Oligonucleotide

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