Analysis of UR-144 and its pyrolysis product in blood and their metabolites in urine

Abstract

UR-144 [(1-pentyl-1H-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl)methanone] is a synthetic cannabinoid, which has been detected in many herbal blends, resinous samples and powders seized from the Polish drug market since the beginning of 2012. This paper presents the case of intoxication by this substance. A complete picture of the symptoms observed by a witness, paramedics and medical doctors are given. In the analysis of powder residues from the plastic bag seized from the intoxicated person by gas chromatography-mass spectrometry (GC-MS), UR-144 and its major pyrolysis product [1-(1-pentyl-1H-indol-3-yl)-3-methyl-2-(propan-2-yl)but-3-en-1-one] were detected. Both substances were also identified in a blood sample collected on admission of the patient to hospital using liquid chromatography-triple quadrupole tandem mass spectrometry (LC-QqQ-MS). Blood concentration of UR-144 was 6.1 ng/mL. A urine sample collected at the same time was analyzed by liquid chromatography-quadruple time-of-flight tandem mass spectrometry (LC-QTOF-MS). The parent substance and its pyrolysis products were not detected in urine, while their five metabolites were found. The experiments allowed the location of derivative groups to be established, and thus elucidate rough structures of the metabolites; a dihydroxylated metabolite of UR-144 and mono-, dihydroxylated and carboxylated metabolites of its pyrolysis product were identified.

Keywords: Analysis; Intoxication; LC–MS/MS; Synthetic cannabinoids; UR-144.