8-Oxoguanine (8-hydroxyguanine, 8-oxo-Gua, or OH8Gua) is one of the most common DNA lesions resulting from reactive oxygen species[2] modifying guanine, and can result in a mismatched pairing with adenine resulting in G to T and C to A substitutions in the genome.[3] In humans, it is primarily repaired by DNA glycosylase OGG1. It can be caused by ionizing radiation, in connection with oxidative metabolism.
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IUPAC name
2-Amino-7,9-dihydro-1H-purine-6,8-dione
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Other names
7,8-Dihydro-8-oxoguanine; 8-Oxo-7,8-dihydroguanine
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3D model (JSmol)
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ChEBI |
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ChemSpider |
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ECHA InfoCard | 100.024.578 |
MeSH | 8-hydroxyguanine |
PubChem CID
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UNII |
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CompTox Dashboard (EPA)
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Properties | |
C5H5N5O2 | |
Molar mass | 167.128 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
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Increased concentrations of 8-oxoguanine in body fluids have been found to be associated with increased risk of mutagenesis and carcinogenesis.[4][5]
Care must be taken in the assay of 8-oxoguanine due to the ease with which it can be oxidised during extraction and the assay procedure.[6]
The role of the deoxyriboside form of 8-oxoguanine, 8-oxo-2'-deoxyguanosine (abbreviated 8-oxo-dG or 8-OHdG) in cancer and aging also applies to 8-oxoguanine. Oxoguanine glycosylase is employed in the removal of 8-oxoguanine from DNA by the process of base excision repair. As described in oxoguanine glycosylase, deficient expression of this enzyme causes 8-oxoguanine to accumulate in DNA. This accumulation may then lead upon replication of DNA to mutations including some that contribute to carcinogenesis. 8-oxoguanine is usually formed by the interaction of reactive oxygen species (ROS) with the guanine base in DNA under conditions of oxidative stress; as noted in the article about them, such species may have a role in aging and male infertility, and 8-oxoguanine can be used to measure such stress.