title: Analysis of the malondialdehyde-2'-deoxyguanosine adduct in rat liver DNA by gas chromatography/electron capture negative chemical ionization mass spectrometry.
abstract: Malondialdehyde (MDA), a product of lipid peroxidation, causes mutations in bacterial and mammalian cells and cancer in rats. MDA reacts with deoxynucleosides in vitro and the monomeric adduct of MDA with deoxyguanosine (M1G-dR) is the major adduct formed. We have developed a sensitive analytical method to characterize and quantify M1G-dR from biological matrices using gas chromatography/electron capture negative chemical ionization mass spectrometry (GC/ECNCI MS). Reduction of M1G-dR with sodium borohydride produced a dihydro derivative (H2-M1G-dR). This more stable analog had improved high-performance liquid chromatographic characteristics which facilitated its isolation from biological fluids. H2-M1G-dR was converted to a monopentafluorobenzyl derivative with simultaneous depurination; it was then converted to the corresponding t-butyldimethylsilyl derivative and analyzed by GC/ECNCI MS. (2H2)H2-M1G was used as internal standard. Quantitative analysis was carried out using selected ion monitoring of m/z 302 and m/z 304 where the limit of detection was 10 pg (30 fmol) injected on-column. The level of M1G-dR in normal rat liver was 5.2 +/- 0.2 modified bases per 10(7) bases (n = 6 rats).
authors.affiliation: A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Vanderbilt University, Nashville, TN 37332.
authors.forename: A K
authors.initials: AK
authors.lastname: Chaudhary
authors.forename: M
authors.initials: M
authors.lastname: Nokubo
authors.forename: L J
authors.initials: LJ
authors.lastname: Marnett
authors.forename: I A
authors.initials: IA
authors.lastname: Blair
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000032:analysis* / Q000302:isolation & purification; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D006868:Hydrolysis; D008099:Liver / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: C089188:3-(2'-deoxyribofuranosyl)pyrimido(1,2-a)purin-10(3H)-one; D004247:DNA; D003849:Deoxyguanosine