Brooks Lydia, Ryan Michael, McCosham Erin, Loganathan Devan
Agriculture & Agri Food Canada, Canadian Pari-Mutuel Agency Research & Reference Laboratory, Ottawa, Ontario, Canada.
Forensic Equine Drug Testing, Bureau Veritas Laboratories, Burnaby, British Columbia, Canada.
Drug Test Anal. 2024 Dec 18;17(8):1357-67. doi: 10.1002/dta.3820.
In 2009, levamisole was identified as a source for several aminorex positives reported in postrace equine samples in Canada. Since then, unexplained detections of aminorex continue to be identified in equine samples where there is no evidence to link these detections to a levamisole administration. Previous studies identified a compound named barbarin in some species of plants from the Brassicaceae family and suggested that barbarin may be a possible precursor for aminorex. The objectives of this study were to (1) investigate the link between barbarin and aminorex and (2) identify other biomarkers of plant origin. Methods were developed and validated for the detection of aminorex, barbarin, glucobarbarin, and other associated compounds. Aminorex was administered to one horse, and barbarin was not detected in any plasma and urine samples. Barbarea stricta and Barbarea orthoceras were administered to two horses, and aminorex was detected in all plasma and urine samples collected. Barbarin was detected in some plasma but not in urine samples. Resedine was observed in retrospective examination of chromatograms of the plant material and from all plants postadministration plasma and urine samples from the two horses. Resedine was administered to one horse and was detected in plasma and urine samples, but aminorex was only detected in urine samples. These results provide evidence that resedine is an intermediary compound between barbarin and aminorex in horses and that resedine can be used as a biomarker to eliminate the reporting of aminorex positives originating from the ingestion of plants from the Brassicaceae family.
2009年，左旋咪唑被确定为加拿大赛后马样本中数例氨基雷司阳性的来源。自那时起，在马样本中持续发现无法解释的氨基雷司检测结果，且没有证据表明这些检测结果与左旋咪唑的使用有关。先前的研究在十字花科的一些植物物种中鉴定出一种名为巴巴林的化合物，并认为巴巴林可能是氨基雷司的一种潜在前体。本研究的目的是：（1）研究巴巴林与氨基雷司之间的联系；（2）鉴定其他植物来源的生物标志物。已开发并验证了检测氨基雷司、巴巴林、葡糖巴巴林及其他相关化合物的方法。给一匹马投喂氨基雷司，在任何血浆和尿液样本中均未检测到巴巴林。给两匹马投喂北美山芥菜和直果山芥，在采集的所有血浆和尿液样本中均检测到氨基雷司。在一些血浆样本中检测到了巴巴林，但尿液样本中未检测到。在对植物材料的色谱图进行回顾性检查以及对两匹马给药后所有植物的血浆和尿液样本中均观察到了雷西丁。给一匹马投喂雷西丁，在血浆和尿液样本中均检测到了雷西丁，但仅在尿液样本中检测到了氨基雷司。这些结果证明，雷西丁是马体内巴巴林与氨基雷司之间的中间化合物，且雷西丁可作为生物标志物，以消除因摄入十字花科植物而导致氨基雷司阳性报告的情况。
