Synthesis and characterization of d5 -barbarin for use in barbarin-related research.

Based on structural similarities and equine administration experiments, Barbarin, 5-phenyl-2-oxazolidinethione from Brassicaceae plants, is a possible source of equine urinary identifications of aminorex, (R,S)-5-phenyl-4,5-dihydro-1,3-oxazol-2-amine, an amphetamine-related US Drug Enforcement Administration (DEA) controlled substance considered illegal in sport horses. We now report the synthesis and certification of d5 -barbarin to facilitate research on the relationship between plant barbarin and such aminorex identifications. D5 -barbarin synthesis commenced with production of d5 -2-oxo-2-phenylacetaldehyde oxime (d5 -oxime) from d5 -acetophenone via butylnitrite in an ethoxide/ethanol solution. This d5 -oxime was then reduced with lithium aluminum hydride (LiAlH4 ) to produce the corresponding d5 -2-amino-1-phenylethan-1-ol (d5 -phenylethanolamine). Final ring closure of the d5 -phenylethanolamine was performed by the addition of carbon disulfide (CS2 ) with pyridine. The reaction product was purified by recrystallization and presented as a stable white crystalline powder. Proton NMR spectroscopy revealed a triplet at 5.88 ppm for one proton, a double doublet at 3.71 ppm for one proton, and double doublet at 4.11 ppm for one proton, confirming d5 -barbarin as the product. Further characterization by high resolution mass spectrometry supports the successful synthesis of d5 -barbarin. Purity of the recrystallized product was ascertained by High Performance Liquid Chromatography (HPLC) to be greater than 98%. Together, we have developed the synthesis and full characterization of d5 -barbarin for use as an internal standard in barbarin-related and equine forensic research.

Aminorex identified in horse urine following consumption of Barbarea vulgaris; a preliminary report.

BACKGROUND: Aminorex, (RS)-5- Phenyl-4,5-dihydro-1,3-oxazol-2-amine, is an amphetamine-like anorectic and in the United States a Drug Enforcement Administration [DEA] Schedule 1 controlled substance. Aminorex in horse urine is usually present as a metabolite of Levamisole, an equine anthelmintic and immune stimulant. Recently, Aminorex identifications have been reported in horse urine with no history or evidence of Levamisole administration. Analysis of the urine samples suggested a botanical source, directing attention to the Brassicaceae plant family, with their contained GlucoBarbarin and Barbarin as possible sources of Aminorex. Since horsepersons face up to a 1 year suspension and a $10,000.00 fine for an Aminorex identification, the existence of natural sources of Aminorex precursors in equine feedstuffs is of importance to both individual horsepersons and the industry worldwide. RESULTS: Testing the hypothesis that Brassicaceae plants could give rise to Aminorex identifications in equine urine we botanically identified and harvested flowering Kentucky Barbarea vulgaris, ("Yellow Rocket") in May 2018 in Kentucky and administered the plant orally to two horses. Analysis of post-administration urine samples yielded Aminorex, showing that consumption of Kentucky Barbarea vulgaris can give rise to Aminorex identifications in equine urine. CONCLUSIONS: Aminorex has been identified in post administration urine samples from horses fed freshly harvested flowering Kentucky Barbarea vulgaris, colloquially "Yellow Rocket". These identifications are consistent with occasional low concentration identifications of Aminorex in equine samples submitted for drug testing. The source of these Aminorex identifications is believed to be the chemically related Barbarin, found as its precursor GlucoBarbarin in Kentucky Barbarea vulgaris and related Brassicaceae plants worldwide.

A cluster of trace-concentration methamphetamine identifications in racehorses associated with a methamphetamine-contaminated horse trailer: A report and analysis.

Three low concentration methamphetamine "positive" tests were linked to use of a methamphetamine-contaminated trailer to transport the affected horses. This incident establishes methamphetamine as a human-use substance that can inadvertently enter the environment of racing horses, resulting in urinary methamphetamine "positives;" an interim regulatory cut-off of 15 ng/mL for methamphetamine in post-race urine is proposed.

Identifications de concentrations de méthamphétamine à l'état de traces chez des chevaux de course associées à une remorque contaminée : rapport et analyse. Trois tests «positifs¼ de faibles concentrations de méthamphétamine ont été associés à l'utilisation d'une remorque contaminée par les méthamphétamines qui était utilisée pour transporter les chevaux affectés. Cet incident établit la méthamphétamine comme une substance à utilisation humaine qui peut pénétrer par inadvertance dans le milieu des chevaux de course, entainant ainsi des tests d'urine «positifs¼; un niveau intérimaire réglementaire de 15 ng/mL pour les méthamphétamines est proposé pour les tests d'urine après la course.(Traduit par Isabelle Vallières).

Solvatomorphism in (E)-2-(2,6-dichloro-4-hydroxybenzylidene)hydrazinecarboximidamide.

The structures of orthorhombic (E)-4-(2-{[amino(iminio)methyl]amino}vinyl)-3,5-dichlorophenolate dihydrate, C(8)H(8)Cl(2)N(4)O·2H(2)O, (I), triclinic (E)-4-(2-{[amino(iminio)methyl]amino}vinyl)-3,5-dichlorophenolate methanol disolvate, C(8)H(8)Cl(2)N(4)O·2CH(4)O, (II), and orthorhombic (E)-amino[(2,6-dichloro-4-hydroxystyryl)amino]methaniminium acetate, C(8)H(9)Cl(2)N(4)O(+)·C(2)H(3)O(2)(-), (III), all crystallize with one formula unit in the asymmetric unit, with the molecule in an E configuration and the phenol H atom transferred to the guanidine N atom. Although the molecules of the title compounds form extended chains via hydrogen bonding in all three forms, owing to the presence of different solvent molecules, those chains are connected differently in the individual forms. In (II), the molecules are all coplanar, while in (I) and (III), adjacent molecules are tilted relative to one another to varying degrees. Also, because of the variation in hydrogen-bond-formation ability of the solvents, the hydrogen-bonding arrangements vary in the three forms.

Polymorphism in 2-(4-hydroxy-2,6-dimethylanilino)-5,6-dihydro-4H-1,3-thiazin-3-ium chloride.

Details of the structures of two conformational polymorphs of the title compound, C(12)H(17)N(2)OS(+)·Cl(-), are reported. In form (I) (space group P-1), the two N-H groups of the cation are in a trans conformation, while in form (II) (space group P2(1)/c), they are in a cis arrangement. This results in different packing and hydrogen-bond arrangements in the two forms, both of which have extended chains lying along the a direction. In form (I), these chains are composed of centrosymmetric R(4)(2)(18) (N-H...Cl and O-H...Cl) hydrogen-bonded rings and R(2)(2)(18) (N-H...O) hydrogen-bonded rings. In form (II), the chains are formed by centrosymmetric R(4)(2)(18) (N-H...Cl and O-H...Cl) hydrogen-bonded rings and by R(4)(2)(12) (N-H...Cl) hydrogen-bonded rings.