TitleFormation of a vitamin C conjugate of acrolein and its paraoxonase-mediated conversion into 5,6,7,8-tetrahydroxy-4-oxooctanal.
Publication TypeJournal Article
Year of Publication2010
AuthorsKesinger NG, Langsdorf BL, Yokochi AF, Miranda CL, Stevens JF
JournalChem Res Toxicol
Date Published2010 Apr 19
KeywordsAcrolein, Aryldialkylphosphatase, Ascorbic Acid, Cell Line, Chromatography, High Pressure Liquid, Humans, Isotope Labeling, Monosaccharides, Recombinant Proteins, Spectrometry, Mass, Electrospray Ionization

Vitamin C (ascorbic acid) has been reported to participate in Michael addition reactions in vitro to form vitamin C conjugates with alpha,beta-unsaturated aldehydes, such as acrolein. This study shows evidence for the formation and metabolism of the vitamin C conjugate of acrolein (AscACR) in cultured human monocytic THP-1 cells exposed to acrolein diacetate. By using (18)O and (13)C labeling in combination with liquid chromatography-tandem mass spectrometry, AscACR was shown to undergo hydrolytic conversion of the ascorbyl lactone into an intermediate carboxylic acid. Subsequent decarboxylation of the carboxylic acid yielded 5,6,7,8-tetrahydroxy-4-oxooctanal (THO). When THP-1 cells were pretreated with ascorbic acid (1 mM, 18 h) and then exposed to acrolein diacetate, THO was detected as its pentafluorobenzyl oxime derivative in the cell lysates and medium. Treatment of THP-1 cells with both ascorbic acid and acrolein diacetate was required for THO formation. The formation of THO from AscACR was facilitated by the lactonase enzymes, human recombinant paraoxonases 1 and 2. THP-1 cells exhibited PON activity, which explains the catalytic conversion of AscACR into THO in these cells. THO was formed in addition to metabolites of the glutathione conjugate of acrolein, indicating that THO formation contributes to the elimination of acrolein in a cellular environment.

Alternate JournalChem. Res. Toxicol.
PubMed ID20353174
PubMed Central IDPMC2858635
Grant ListS10 RR022589 / RR / NCRR NIH HHS / United States
S10 RR022589-010001 / RR / NCRR NIH HHS / United States
R01 HL081721-04 / HL / NHLBI NIH HHS / United States
R01 HL081721 / HL / NHLBI NIH HHS / United States
P30 ES000210-41 / ES / NIEHS NIH HHS / United States
R01HL081721 / HL / NHLBI NIH HHS / United States
P30 ES000210 / ES / NIEHS NIH HHS / United States