Quantitative Determination of 8-Hydroxyguanine and Guanine by Isotope Dilution Mass Spectrometry

✍ Scribed by M. Hamberg; L.Y. Zhang

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 758 KB
• Volume: 229
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.1995.1422

✦ Synopsis

8-[4,5,6,8- (\left.{ }^{13} \mathrm{C}{4}\right]) Hydroxyguanine and (\left[4,5,6-{ }^{13} \mathrm{C}{3}\right]) guanine were prepared by total synthesis. The labeled compounds were used as internal standards in a gasliquid 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. 1995 Academic Press, Inc.