SYNTHESIS OF [4,5,6,8-C-13(4)]GUANINE, A REAGENT FOR THE PRODUCTION OF INTERNAL STANDARDS OF GUANYL DNA-ADDUCTS

Using readily available labeled compounds, [4,5,6,8-C-13(4)]guanine wa s synthesized in high overall yield. Intermediates as well as the fina l product were characterized by H-1 NMR, C-13 NMR, and high resolution mass spectrometry. The labeled guanine was used to generate [C-13(4)] -labeled analogs of the guanine adducts, N-2,3-ethenoguanine and 7-(2- hydroxyethyl)guanine. The application of such adducts in isotope dilut ion mass spectrometry was illustrated with DNA samples from rats expos ed to two different mutagenic compounds, vinyl chloride and ethylene o xide.