Nucleic acid bases epoxides

Analytical procedures for foods are generally based on extraction with purified solvents following saponification with alcoholic potash. Purification of the extracts by chromatography on column or plates is followed by analysis of the purified extract using TLC, GLC or HPLC. Spectrophotometric or spectrofluorimetric methods may be used for quantitation of the hydrocarbons a collaborative study of a spectrophotometric method showed it to be applicable at the 2 fig/kg level. HPLC techniques using spectrofluorimetric detection have been described for which improved levels of detection are claimed. Benzo(a)pyrene produces substitution products with nucleic acids. Hydrocarbon deoxyribonucleoside adducts may be isolated from DNA by gel permeation chromatography, and the formation of hydrocarbon epoxides by mammalian enzyme reaction has also been demonstrated . The limit of detection of spectrophotometric and fluorimetric methods has been improved by three orders of magnitude by the use of laser-induced fluorescence procedures for the... 

Strong bases hydrolyze nucleic bases slowly and ammonia is released. Acids, however, often stabilize the urea-type heterocycles. The basic lactam oxygen is protonated and converts the bases to aromatic systems (compare with Scheme 8.5.4). The C=C double bonds can usually be removed by catalytic hydrogenation or Michael addition of hydride or other nucleophiles (Scheme 8.5.1). Oxidation with peracids, on the other hand, usually gives N-oxides rather than epoxides (Suhadolnik, 1979 Shabarova and Bogdanov, 1994). 

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