Characterization of reaction products between styrene oxide and deoxynucleosides and DNA

Styrene oxide was reacted with deoxynucleosides and DNA in aqueous buffer at pH 7.4. The products were purified by HPLC, characterized by UV spectroscopy and by chemical ionization mass spectrometry. The main products identified were 7-alkyl-, N²-alkyl- and O⁶-alkyldeoxyguanosine, 1-alkyl-, and N⁶-alkyldeoxyadenosine, N⁴-alkyl-, 3-alkyl- and O²-alkyldeoxycytidine and 3-alkylthymidine. The relative yields of alkylated deoxynucleosides were dG>dC>dA>T. In the reactions of styrene oxide with DNA the dominant product isolated was 7-alkylguanine but N²-alkylguanine was also detected.