title: The radiosensitivity of 5- and 6-bromocytidine derivatives--electron induced DNA degradation.
abstract: Halogenated nucleotides belong to the group of radiosensitizers that sensitize solid tumors when incorporated into genomic DNA. Here, we consider the propensity of two isomeric bromocytidine derivatives, 3',5'-diphosphates of 5-bromo-2'-deoxycytidine (5BrdCDP) and 6-bromo-2'-deoxycytidine (6BrdCDP), to be damaged by electrons - one of the most abundant products formed during radiotherapy. An intranucleotide degradation mechanism leading to phosphodiester bond breakage (a model of single strand breakage in labeled DNA) and a ketone derivative formation was found for 6BrdCDP, while for 5BrdCDP a similar mechanism is sterically hindered. 5BrdCDP is, therefore, suggested to undergo electron induced degradation involving hydrogen transfer from a neighboring nucleotide or environment.
authors.affiliation: Department of Chemistry, University of Gdansk, 80-308 Gdansk, Poland. janusz.rak@ug.edu.pl.
authors.forename: Lidia
authors.initials: L
authors.lastname: Chomicz
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Golon
authors.forename: Janusz
authors.initials: J
authors.lastname: Rak
mesh_terms: D001972:Bromodeoxycytidine / Q000031:analogs & derivatives* / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D004583:Electrons; D011789:Quantum Theory
chemical_list: C000597715:6-bromo-2'-deoxycytidine; D001972:Bromodeoxycytidine; D004247:DNA