Formation of 8-hydroxyguanine and 2,6-diamino-4-hydroxy-5-formamidopyrimidine in DNA by riboflavin mediated photosensitization.

Abstract

Calf thymus DNA was photoirradiated in the presence of riboflavin. Altered bases were detected and quantified by the GC/MS-SIM method after hydrolysis and derivatization of DNA. Seven types of modified purine bases were detected in control DNA. Among them, the yields of 8-OH-Gua and FapyGua increased significantly in DNA photo-irradiated with riboflavin, whereas the yields of xanthine, 8-OH-Ade, 2-OH-Ade, FapyAde and hypoxanthine were not affected. A dose dependent increase in the formation of 8-OH-Gua was observed with increasing riboflavin concentration for 30 min irradiation. On the other hand, FapyGua reached plateau at 10 micrograms/ml of riboflavin for 30 min irradiation. Our results indicate that guanine moiety in DNA is the most susceptible to riboflavin mediated photosensitization.

• Authors: T Mori, K Tano, K Takimoto, H Utsumi
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 242 Issue 1 Pg. 98-101 (Jan 06 1998) ISSN: 0006-291X [Print] United States
• PMID: 9439617 (Publication Type: Journal Article)

Chemical References

• Photosensitizing Agents
• Pyrimidines
• 2,6-diamino-4-hydroxy-5-formamidopyrimidine
• 8-hydroxyguanine
• Guanine
• DNA
• Riboflavin

Topics

• Animals
• Cattle
• DNA (chemistry, radiation effects)
• Gas Chromatography-Mass Spectrometry
• Guanine (analogs & derivatives, analysis)
• Light
• Photosensitizing Agents
• Pyrimidines (analysis)
• Riboflavin