Synthesis of Internally Linked Carbazole DNA Oligomers: A Potential Monitor for Charge Transfer in DNA Studies

• Main Author: Umeweni, Chiko
• Format: Others
• Language: en_US
• Published: Georgia Institute of Technology 2005
• Subjects: Uridine; Modified nucleoside; Nucleoside modification; Anthraquinone; Tetraquinone; Hole trap
• Online Access: http://hdl.handle.net/1853/7197

In duplex DNA, guanine radical cations react with water to form mainly 7,8-dihydro-8-oxoguanine (8-OxoG). Understanding for the mechanism for migration of a radical cation (hole) from the site of initial DNA oxidation to a remote guanine is an important step in the process that will lead to a thorough understanding of DNA damage and its repair. The vast majority of charge migration in DNA experiments utilize guanine oxidation as a monitor for charge transfer. The synthesis of a potential monitor for charge transfer through DNA that is independent of guanine oxidation is reported herein. The system is a carbazole moiety covalently attached to the 2O position of uridine which was successfully incorporated into a DNA strand. Carbazole has a low oxidation potential, and will create a deeper trap than guanine during DNA charge transfer. One electron oxidation of carbazole should lead to the formation of its radical cation. The high extinction coefficient of carbazole radical cation should make it clearly observable with UV analysis. Hence a monitor for charge migration in DNA independent of guanine oxidation is obtained.