Pterin
From Wikipedia, the free encyclopedia
| Pterin | |
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| IUPAC name | 2-amino-1H-pteridin-4-one |
| Other names | Pteridoxamine Pterine 4-Oxopterin 2-Amino-4-pteridone 2-Amino-4-hydroxypteridine 2-Amino-4-oxopteridine 2-aminopteridin-4-ol 2-Amino-4-pteridinol |
| Identifiers | |
| CAS number | [2236-60-4] |
| PubChem | |
| SMILES | C1=CN=C2C(=N1)C(=O)N=C(N2)N |
| Properties | |
| Molecular formula | C6H5N5O |
| Molar mass | 163.14 g mol-1 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Pterin is a heterocyclic compound composed of a pyrazine ring and a pyrimidine ring (a pteridine ring system); the pyrimidine ring has a carbonyl oxygen and an amino group. Several tautomers of pterin exist and are shown below. As a group, pterins are compounds that are derivatives of 2-amino-4-oxopteridine, with additional functional groups attached to the pyrazine ring.
Pterins were first discovered in the pigments of butterfly wings (hence the origin of their name, from the Greek pteron, wing) and perform many roles in coloration in the biological world. Pterins also function as cofactors in enzyme catalysis.
Folates, are “conjugated” pteridines, which contain para-aminobenzoic acid and glutamates at the 6 position on the pteridine ring, are critical compounds in a large number of biological group transfer reactions. These folate-dependent biosynthetic reactions include transfer of methyl groups to homocystine in the S-adenosyl methionine cycle, and formyl groups to methionine to form N-formylmethionine in initiator tRNAs.
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[edit] Tautomers of pterin
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[edit] Biosynthesis
The biosynthesis of pterins begins with the molecule guanosine triphosphate (GTP); the enzyme which controls the conversion of GTP to pterin, GTP cyclohydrolase I, is found in both prokaryotes and eukaryotes.
[edit] Other pterins
Pterin can exist in many different forms in nature depending on its function. Tetrahydrobiopterin, the major unconjugated pteridine in vertebrates, is a co-factor in the hydroxylation of aromatic compounds and synthesis of nitric oxide. Molybdopterin is a substituted pteridine that binds molybdenum to give redox enzymes involved in biological hydroxylations, reduction of nitrate, and respiratory oxidation. Tetrahydromethanopterin is used in methanogenic organisms. Cyanopterin is a glycosylated version of pteridine of unknown function in cyanobacteria.
