抄録
When 8-oxo-7,8-dihydro-2'-deoxyguanosine in potassium phosphate buffer of pH 7.4 was irradiated by UV light from a mercury lamp, two major products were formed. They were identified as the diastereomers of spiroiminodihydantoin deoxyribonucleoside on the basis of their identical ESI-MS and UV spectra and HPLC retention times with those of the authentic samples. Degradation of 8-oxo-7,8-dihydro-2'-deoxyguanosine by UV light was faster than those of 2'-deoxyguanosine, 2'-deoxycytidine, 2'-deoxyadenosine, and thymidine. Sunlight also generated the diastereomers of spiroiminodihydantoin from 8-oxo-7,8-dihydro-2'-deoxyguanosine. The results suggest that sunlight may induce 8-oxo-7,8-dihydroguanine oxidation in DNA, generating spiroiminodihydantoin in humans.
