title: Formation of 5-hydroxy-5,6-dihydrouracil and release of undamaged uracil as a result of poly(U) irradiation in N2O-saturated aqueous solution.
abstract: The radiation chemical yields of 5-hydroxy-5,6-dihydrouracil and uracil were measured on radiolysis of N2O-saturated solutions containing I mmol dm-3 poly(U) and were found to be 0.04 and 0.31 mumol J-1 respectively. From the 5-hydroxy-5,6-dihydrouracil yield in the presence of cysteamine and 2-mercaptoethanol, it is shown that only 20% of the OH-radicals, which attack poly(U) results in the formation of 5-hydroxy uracil adducts. It has been proposed that as yet unknown reducing radicals are formed in addition to known reducing radicals (the 5-OH-adducts of uracil, the H-adducts of uracil, and sugar radicals) as a result of the reaction of OH-radicals with poly(U).
mesh_terms: D017665:Hydroxyl Radical / Q000378:metabolism*; D011072:Poly U / Q000528:radiation effects*; D014498:Uracil / Q000378:metabolism*
chemical_list: D011072:Poly U; D017665:Hydroxyl Radical; D014498:Uracil