title: Identification of trans,trans-2,4-decadienal metabolites in mouse and human cells using liquid chromatography-mass spectrometry.
abstract: trans,trans-2,4-Decadienal (tt-DDE), a lipid peroxidation product of linolieic acid, is the most abundant aldehyde identified in cooking oil fumes and is readily detectable in food products as well as in restaurant emissions. Previously, we have reported the toxicological effects of tt-DDE in vitro and in vivo. However, the metabolic pathways of tt-DDE in vivo remain unclear. In our present study, we combined liquid chromatography-mass spectrometry with triple quadrupole and time-of-flight to identify tt-DDE metabolites in the urine of mice orally administered tt-DDE. We identified two tt-DDE metabolites, 2,4-decadienoic acid and cysteine-conjugated 2,4-decadien-1-ol, in the urine of mice gavaged with tt-DDE and in human hepatoma cell cultures. The structure of 2,4-decadienoic acid was confirmed upon comparison of its tandem mass spectrometry (MS/MS) spectrum and retention time with those of synthetic standards. The moieties of cysteine and alcohol on cysteine-conjugated 2,4-decadien-1-ol were validated by treating cell cultures with stable-isotope-labeled cysteine and 4-methylpyrazole, an alcohol dehydrogenase inhibitor. The MS/MS spectra of a cysteine standard and ionized cysteine detached from cysteine-conjugated 2,4-decadien-1-ol were identical. Two metabolic pathways for the biotransformation of tt-DDE in vivo are proposed: (i) the oxidation of tt-DDE to the corresponding carboxylic acid, 2,4-decadienoic acid, in liver cells and (ii) glutathione (GHS) conjugation, GSH breakdown, and aldehyde reduction, which generate cysteine-conjugated 2,4-decadien-1-ol in both liver and lung cells. In conclusion, this platform can be used to identify tt-DDE metabolites, and cysteine-conjugated 2,4-decadien-1-ol can serve as a biomarker for assessing exposure to tt-DDE.
authors.affiliation: National Environmental Health Research Center, National Health Research Institutes , Zhunan 35053, Taiwan.
authors.forename: Kao-Lu
authors.initials: KL
authors.lastname: Pan
authors.forename: Wei-Jan
authors.initials: WJ
authors.lastname: Huang
authors.forename: Ming-Hua
authors.initials: MH
authors.lastname: Hsu
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Lee
authors.forename: Huei-Ju
authors.initials: HJ
authors.lastname: Liu
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Cheng
authors.forename: Ming-Hsien
authors.initials: MH
authors.lastname: Tsai
authors.forename: Mei-Ya
authors.initials: MY
authors.lastname: Shen
authors.forename: Pinpin
authors.initials: P
authors.lastname: Lin
mesh_terms: D000447:Aldehydes / Q000032:analysis* / Q000494:pharmacology / Q000652:urine; D000818:Animals; D015415:Biomarkers / Q000032:analysis / Q000652:urine; D001711:Biotransformation; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000737:chemistry; D000077604:Fomepizole; D005978:Glutathione / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007536:Isomerism; D007553:Isotope Labeling; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010084:Oxidation-Reduction; D011720:Pyrazoles / Q000737:chemistry; D053719:Tandem Mass Spectrometry
chemical_list: D000447:Aldehydes; D015415:Biomarkers; D011720:Pyrazoles; C057349:2,4-decadienal; D000077604:Fomepizole; D005978:Glutathione; D003545:Cysteine