Synthesis and characterization of barbarin, a possible source of unexplained aminorex identifications in forensic science.
Abstract: Aminorex is a US DEA Schedule 1 controlled substance occasionally detected in racing horses. A number of aminorex identifications in sport horses were thought to have been caused by exposure to plant sources of aminorex. Glucobarbarin, found in plants of the Brassicaceae family, has been suggested as a potential proximate chemical source by being metabolized in the plant or the horse to aminorex. In Brassicaceae, glucobarbarin is hydrolyzed by myrosinase to yield barbarin, which serves as an insect repellant and/or attractant and is structurally related to aminorex. The synthesis, purification, and characterization of barbarin is now reported for use as a reference standard in aminorex related research concerning equine urinary identifications of aminorex and also for possible use in equine administration experiments. Synthesis of barbarin was performed via ring closure between phenylethanolamine and carbon disulfide in tetrahydrofuran with the catalyst pyridine under reflux. The reaction yielded a white crystalline substance that was purified and chemically characterized as barbarin for use as a Certified Reference Standard or for studies related to equine aminorex identification.
© 2020 John Wiley & Sons, Ltd.
Publication Date: 2020-08-26 PubMed ID: 32567235DOI: 10.1002/dta.2883Google Scholar: Lookup
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- Journal Article
Summary
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The research article is about the synthesis and characterization of a compound called barbarin, which may be linked to unexplained detections of a controlled substance, aminorex, in racing horses.
Understanding the Research Context
- This research revolves around aminorex, a DEA Schedule 1 controlled substance. Aminorex has been detected occasionally in sports horses, which led to speculations that these incidences could be due to the consumption of plant-based sources that metabolise or transform into aminorex.
- The plant compound glucobarbarin, found in certain plants of the Brassicaceae family, was suggested as a plausible chemical source. In these plants, glucobarbarin is broken down by an enzyme called myrosinase to produce the compound barbarin. Barbarin is not only structurally similar to aminorex, but also acts as an insect repellent and attractant.
Objective of the Study
- The study aims to synthesize and characterize barbarin for use as a reference material in related research, including the investigation of equine urinary identifications of aminorex. Furthermore, it could also be used in administration experiments on horses.
Synthesis of Barbarin
- The researchers synthesized barbarin through a ring closure reaction between the compounds phenylethanolamine and carbon disulfide. This was performed in a chemical solvent known as tetrahydrofuran, with pyridine serving as a catalyst. The process was performed under reflux conditions, meaning it was boiled and condensed in a cyclic manner, which allows the reaction to take place over a longer period of time and at a higher temperature.
- The result of the reaction was a white crystalline substance, which was cleaned and characterized chemically as barbarin. It can now be used as a Certified Reference Standard for studies related to equine aminorex identification.
Cite This Article
APA
Machin J, Childers T, Kudrimoti S, Eisenberg R, Fenger C, Hartmann P, Maylin G, Shults T, Tobin T.
(2020).
Synthesis and characterization of barbarin, a possible source of unexplained aminorex identifications in forensic science.
Drug Test Anal, 12(10), 1477-1482.
https://doi.org/10.1002/dta.2883 Publication
Researcher Affiliations
- Department of Toxicology and Cancer Biology and the Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA.
- Department of Toxicology and Cancer Biology and the Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA.
- Department of Toxicology and Cancer Biology and the Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA.
- Frontier BioPharm, LLC, Richmond, Kentucky, USA.
- Equine Integrated Medicine, Georgetown, Kentucky, USA.
- Industrial Laboratories Co, Wheat Ridge, CO, USA.
- New York Drug Testing and Research Program, Ithaca, NY, USA.
- American Association of Medical Review Officers, Durham, NC, USA.
- Department of Toxicology and Cancer Biology and the Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA.
MeSH Terms
- Aminorex / analysis
- Animals
- Chemistry Techniques, Synthetic
- Doping in Sports
- Forensic Sciences
- Horses
- Illicit Drugs / analysis
- Oxazoles / analysis
- Oxazoles / chemical synthesis
- Reference Standards
- Substance Abuse Detection / standards
References
This article includes 19 references
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Citations
This article has been cited 1 times.- Kudrimoti S, Machin J, Arojojoye AS, Awuah SG, Eisenberg R, Fenger C, Maylin G, Lehner AF, Tobin T. Synthesis and characterization of d(5) -barbarin for use in barbarin-related research. Drug Test Anal 2023 Jan;15(1):42-46.
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