Generation of free radical and hydrogen peroxide from 2-hydroxyemodin, a direct-acting mutagen, and DNA strand breaks by active oxygen.
Among several hydroxylated metabolites of emodin, a fungal anthraquinone and constituent of rhubarb, 2-hydroxyemodin was a direct-acting mutagen showing a large electron-spin resonance (ESR) signal in the presence of DNA, especially at alkaline pH. Coupled with generation of free radical, hydrogen peroxide but not superoxide was formed. The active oxygen produced from 2-hydroxyemodin induced strand breaks in phi X 174 replicative form I DNA (supercoiled covalently closed circular duplex DNA). These results suggest a possible role of active oxygen in the process of mutagenesis.
Kodama
M
M
Kamioka
Y
Y
Nakayama
T
T
Nagata
C
C
Morooka
N
N
Ueno
Y
Y
D000880:Anthraquinones / Q000633:toxicity*; D004278:DNA, Superhelical / Q000187:drug effects*; D004642:Emodin / Q000031:analogs & derivatives / Q000633:toxicity*; D005609:Free Radicals; D006861:Hydrogen Peroxide / Q000096:biosynthesis*; D006863:Hydrogen-Ion Concentration; D009152:Mutagenicity Tests; D010100:Oxygen / Q000633:toxicity; D012486:Salmonella typhimurium
D000880:Anthraquinones; D004278:DNA, Superhelical; D005609:Free Radicals; C053054:2-hydroxyemodin; D006861:Hydrogen Peroxide; D004642:Emodin; D010100:Oxygen