5,6-Dihydro-5(α-thyminyl)thymine explained

5,6-Dihydro-5(α-thyminyl)thymine is a DNA pyrimidine dimer photoproduct produced when DNA in bacterial spores is exposed to ultraviolet light.^[1] In bacteria, this DNA base dimer deforms the structure of DNA, so endospore forming bacteria have an enzyme called spore photoproduct lyase that repairs this damage.^[2]

Laboratory synthesis

5,6-Dihydro-5(α-thyminyl)thymine can also be synthesized in a laboratory by reacting 5-hydroxymethyluracil and 6-aminothymine yielding 5,6-dihydro-6-imino-5-(α-thyminyl)thymine. When hydrogen is added in a reduction then 5,6-dihydro-5(α-thyminyl)thymine is the product.^[3]

Notes and References

1. Varghese . A.J. . 5-Thyminyl-5,6-dihydrothymine from DNA irradiated with ultraviolet light . Biochemical and Biophysical Research Communications . February 1970 . 38 . 3 . 484–490 . 10.1016/0006-291x(70)90739-4 . 5462695 .
2. Moeller . Ralf . Douki . Thierry . UV-radiation-induced formation of DNA bipyrimidine photoproducts in Bacillus subtilis endospores and their repair during germination . International Microbiology . 2007 . 1 . 10 . 39–46 . 10.2436/20.1501.01.6.
3. Bergstrom . Donald E. . Rash . Kenneth F. . Synthesis of a photoproduct from ultraviolet-irradiation of bacterial spores: 5,6-dihydro-5-(α-thyminyl)thymine . J. Chem. Soc., Chem. Commun. . 1978 . 7 . 284 . 10.1039/C39780000284.