Characterization of alkyl-cobalamins formed on trapping of epoxide metabolites of 1,3-butadiene.
Analytical methods facilitating studies of electrophilically reactive and genotoxic compounds in vitro and in vivo are needed. The strong nucleophile, cob(I)alamin, formed by reduction of Vitamin B12 [cob(III)alamin], may be used for trapping and analysis of 1,2-epoxides and other electrophiles. In the present study, cob(I)alamin is evaluated as an analytical tool for 1,2-epoxide metabolites (oxiranes) of 1,3-butadiene. Products of reaction of cob(I)alamin with 1,2-epoxy-3-butene (EB), 1,2:3,4-diepoxybutane (DEB), and 1,2-epoxy-3,4-butanediol (EBdiol) have been analyzed by reversed phase high performance liquid chromatography (HPLC) coupled on-line to electrospray ionization mass spectrometry (ESI-MS) and ultraviolet diode array detection (UV-DAD). It was shown that a specific alkyl-CbI complex is formed for each metabolite and that it was possible to discriminate between the products by HPLC-UV and by LC-MS. Quantification of DEB with the method by use of another 1,2-epoxide as an internal standard was successfully performed. The possibility of using cob(I)alamin for trapping and analysis of the three oxirane metabolites of 1,3-butadiene will facilitate quantitative comparisons of species in vitro with regard to metabolism of 1,3-butadiene.
Fred
Charlotta
C
Department of Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
Haglund
Johanna
J
Alsberg
Tomas
T
Rydberg
Per
P
Minten
Johanna
J
Törnqvist
Margareta
M
D002070:Butadienes / Q000737:chemistry* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004852:Epoxy Compounds / Q000737:chemistry* / Q000302:isolation & purification; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D014805:Vitamin B 12 / Q000737:chemistry*
D002070:Butadienes; D004852:Epoxy Compounds; D014805:Vitamin B 12