中文摘要：霉菌毒素4-脱氧雪腐镰刀菌烯醇（DON）谷胱甘肽(GSH)结合物，连同一系列相关的结合物，最近已通过LC-MS法分析经DON处理的小麦穗得到了初步鉴定。本研究制备了GSH, Cys, CysGly, γ-GluCys和氮乙酰半胱氨酸(NAC)与DON在10和13位点的给合物。将这些物质的混合物作为标准，用LC-HRMS法分析经人工DON处理的小麦穗，及受浓度高于1mg/kg的DON自然污染的19个挪威春小麦和16个燕麦样品。结果发现，由于DON和其它单端孢霉烯在13位点的结合不可逆，因此这类结合物可用作DON和其它12，13-环氧单端孢霉烯的生物标志物。
外文摘要：A glutathione (GSH) adduct of the mycotoxin 4-deoxynivalenol (DON), together with a range of related conjugates, has recently been tentatively identified by LC-MS of DON-treated wheat spikelets. In this study, we prepared samples of DON conjugated at the 10- and 13-positions with GSH, Cys, CysGly, γ-GluCys and N-acetylcysteine (NAC). The mixtures of conjugates were used as standards for LC-HRMS analysis of one of the DON-treated wheat spikelet samples, as well as 19 Norwegian grain samples of spring wheat and 16 grain samples of oats that were naturally-contaminated with DON at concentrations higher than 1 mg/kg. The artificially-contaminated wheat spikelets contained conjugates of GSH, CysGly and Cys coupled at the olefinic 10-position of DON, whereas the naturally-contaminated harvest-ripe grain samples contained GSH, CysGly, Cys, and NAC coupled mainly at the 13-position on the epoxy group. The identities of the conjugates were confirmed by LC-HRMS comparison with authentic standards, oxidation to the sulfoxides with hydrogen peroxide, and examination of product-ion spectra from LC-HRMS/MS analysis. No γ-GluCys adducts of DON were detected in any of the samples. The presence of 15-O-acetyl-DON was demonstrated for the first time in Norwegian grain. The results indicate that a small but significant proportion of DON is metabolized via the GSH-conjugation pathway in plants. To our knowledge, this is the first report of in vivo conjugation of trichothecenes via their epoxy group, which has generally been viewed as unreactive. Because conjugation at the 13-position of DON and other trichothecenes has been shown to be irreversible, this type of conjugate may prove useful as a biomarker of exposure to DON and other 12,13-epoxytrichothecenes.
外文关键词：bioconjugation；HRMS；mercapturate；mycotoxin；trichothecene；thiol；LC-MS；metabolism；wheat；oats
作者：Uhlig, S；Stanic, A；Hofgaard, IS；Kluger, B；Schuhmacher, R；Miles, CO
作者单位：Norwegian Vet Inst
期刊名称：TOXINS
期刊影响因子：3.571
出版年份：2016
出版刊次：11
点击下载：自然污染的谷物中脱氧雪腐镰刀菌烯醇主要通过环氧基团与谷胱甘肽结合