Reaction of the Butter Flavorant Diacetyl (2,3-Butanedione) with N-α-Acetylarginine: A Model for Epitope Formation with Pulmonary Proteins in the Etiology of Obliterative Bronchiolitis
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- 作者：James M. Mathews ; Scott L. Watson ; Rodney W. Snyder ; Jason P. Burgess ; Daniel L. Morgan
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2010
- 出版时间：December 22, 2010
- 年：2010
- 卷：58
- 期：24
- 页码：12761-12768
- 全文大小：901K
- 年卷期：v.58,no.24(December 22, 2010)
- ISSN：1520-5118
文摘
The butter flavorant diacetyl (2,3-butanedione) is implicated in causing obliterative bronchiolitis in microwave popcorn plant workers. Because diacetyl modifies arginine residues, an immunological basis for its toxicity is under investigation. Reaction products of diacetyl with N-α-acetylarginine (AcArg) were determined as a model for hapten formation, with characterization by mass spectrometry, NMR, and HPLC with UV detection and radiodetection. Four products were identified by LC-MS, each with a positive ion of m/z 303 (diacetyl + AcArg); one pair displayed an additional ion at m/z 217 (AcArg), the other pair at m/z 285 (− H2O). Their 1H−13C NMR correlation spectra were consistent with the addition of one or two of the guanidine nitrogens to form aminols. Open-chain pairs interconverted at pH 2, as did the cyclized, but all four interconverted at neutral pH. This is the first structural characterization of the covalent adducts between diacetyl and an arginine moiety.