title: Photoaddition of 5-bromouracil to uracil in oligonucleotides leading to 5,5'-bipyrimidine-type adducts: mechanism of the photoreaction.
abstract: 5-Bromouracil ((Br)U) modified di- and hexanucleotides having (Br)U flanked on the 5' or the 3' side by uracil (U) have been synthesized, and their photochemical reactivity was examined under the conditions of irradiation with near UV light. The results indicate that the primary photochemical process in all of these compounds involves the formation of an intermediate cyclobutane phodoadduct composed of (Br)U and U, which undergoes further photochemically and thermally induced transformations to 5,5'-bipyrimidine type adducts.
authors.affiliation: Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Lepczyńska
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Komodziński
authors.forename: Jan
authors.initials: J
authors.lastname: Milecki
authors.forename: Ryszard
authors.initials: R
authors.lastname: Kierzek
authors.forename: Zofia
authors.initials: Z
authors.lastname: Gdaniec
authors.forename: Stefan
authors.initials: S
authors.lastname: Franzen
authors.forename: Bohdan
authors.initials: B
authors.lastname: Skalski
mesh_terms: D001976:Bromouracil / Q000737:chemistry*; D009841:Oligonucleotides / Q000737:chemistry*; D055668:Photochemical Processes
chemical_list: D009841:Oligonucleotides; D001976:Bromouracil