A carbon-centered radical as a reaction species in the DNA strand-breakage by D-glucosamine.
Electron spin resonance(ESR) studies using 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and sodium 3,5-dibromo-4-nitrosobenzensulfonate (DBNBS) as a spin-trapping agent revealed the formation of both hydroxyl and carbon-centered radical-derived spin adducts in Cu2+-containing 50 mM Tris-HCl buffered solutions (pH 7.1) of D-glucosamine, D-mannosamine, and D-galactosamine, which were previously shown to have the ability to break the single-strand of plasmid pBR322 DNA in a nucleotide sequence-specific manner. HCl-free D-glucosamine has higher DNA breaking activity, and this activity is promoted more by the presence of Cu2+ than the original D-glucosamine hydrochloride, exhibits stronger radical signals in the ESR spectrum. It is suggested that D-glucosamine is unstable around neutral pH, being converted into certain intermediate(s) such as a dihydropyrazine compound, which generate(s) carbon-centered radicals, and that, besides the hydroxyl radical, the intermediate(s) is/are responsible for DNA strand breakage.
Yamaguchi
T
T
Department of Hygiene, Miyazaki Medical College, Japan.
Kashige
N
N
Matsumoto
S
S
Satoh
K
K
Yasuda
M
M
Watanabe
K
K
D001557:Benzenesulfonates; D002244:Carbon / Q000737:chemistry*; D003497:Cyclic N-Oxides; D004247:DNA / Q000187:drug effects; D004249:DNA Damage; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D005944:Glucosamine / Q000494:pharmacology*; D009603:Nitroso Compounds; D013113:Spin Labels
D001557:Benzenesulfonates; D003497:Cyclic N-Oxides; D005609:Free Radicals; D009603:Nitroso Compounds; D013113:Spin Labels; C017245:5,5-dimethyl-1-pyrroline-1-oxide; D002244:Carbon; C048757:3,5-dibromo-4-nitrosobenzenesulfonate; D004247:DNA; D005944:Glucosamine