title: Quantitative determination of 8-hydroxyguanine and guanine by isotope dilution mass spectrometry.
abstract: 8-[4,5,6,8-13C4]Hydroxyguanine and [4,5,6-13C3]guanine were prepared by total synthesis. The labeled compounds were used as internal standards in a gas-liquid chromatographic-mass spectrometric method for quantitative determination of 8-hydroxyguanine and guanine in DNA. The approach used made it possible to directly determine the ratio between 8-hydroxyguanine and guanine, expressed as the number of molecules of 8-hydroxyguanine per 10(5) molecules of guanine, in the sample of DNA analyzed. A method for trimethylsilylation of 8-hydroxyguanine and guanine at room temperature was developed. Use of this method for derivatization gave levels of 8-hydroxyguanine in calf thymus DNA which were lower than those recently found by gas chromatography-mass spectrometry but similar to those determined by high-performance liquid chromatography with electrochemical detection.
mesh_terms: D000818:Animals; D002247:Carbon Isotopes; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006147:Guanine / Q000031:analogs & derivatives* / Q000032:analysis*; D007118:Immunoassay / Q000379:methods; D007202:Indicators and Reagents; D007553:Isotope Labeling / Q000379:methods; D007700:Kinetics; D008027:Light; D013950:Thymus Gland
chemical_list: D002247:Carbon Isotopes; D007202:Indicators and Reagents; C024829:8-hydroxyguanine; D006147:Guanine; D004247:DNA