title: Development of a mass spectrometric hydroxyl-position determination method for the hydroxyindole metabolites of JWH-018 by GC-MS/MS.
abstract: One of the many issues of designer drugs of abuse like synthetic cannabinoids (SCs) such as JWH-018 is that details on their metabolism has yet to be fully elucidated and that multiple metabolites exist. The presence of isomeric compounds poses further challenges in their identification. Our group has previously shown the effectiveness of gas chromatography-electron ionization-tandem mass spectrometry (GC-EI-MS/MS) in the mass spectrometric differentiation of the positional isomers of the naphthoylindole-type SC JWH-081, and speculated that the same approach could be used for the metabolite isomers. Using JWH-018 as a model SC, the aim of this study was to differentiate the positional isomers of its hydroxyindole metabolites by GC-MS/MS. Standard compounds of JWH-018 and its hydroxyindole metabolite positional isomers were first analyzed by GC-EI-MS in full scan mode, which was only able to differentiate the 4-hydroxyindole isomer. Further GC-MS/MS analysis was performed by selecting m/z 302 as the precursor ion. All four isomers produced characteristic product ions that enabled the differentiation between them. Using these ions, MRM analysis was performed on the urine of JWH-018 administered mice and determined the hydroxyl positions to be at the 6-position on the indole ring. GC-EI-MS/MS allowed for the regioisomeric differentiation of the hydroxyindole metabolite isomers of JWH-018. Furthermore, analysis of the fragmentation patterns suggests that the present method has high potential to be extended to hydroxyindole metabolites of other naphthoylindole type SCs in identifying the position of the hydroxyl group on the indole ring. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Legal Medicine and Bioethics, Nagoya University, Nagoya, Japan.
authors.forename: Maiko
authors.identifier: 0000-0003-1892-372X
authors.initials: M
authors.lastname: Kusano
authors.affiliation: Department of Legal Medicine and Bioethics, Nagoya University, Nagoya, Japan.|Institute for Advanced Research, Nagoya University, Nagoya, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Zaitsu
authors.affiliation: Department of Legal Medicine and Bioethics, Nagoya University, Nagoya, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Yamanaka
authors.affiliation: Department of Legal Medicine and Bioethics, Nagoya University, Nagoya, Japan.|Forensic Science Laboratory, Aichi Prefectural Police Headquarters, Aichi, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Hisatsune
authors.affiliation: Department of Legal Medicine and Bioethics, Nagoya University, Nagoya, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Asano
authors.affiliation: Department of Legal Medicine and Bioethics, Nagoya University, Nagoya, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Taki
authors.affiliation: Institute for Advanced Research, Nagoya University, Nagoya, Japan.|Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Department of Legal Medicine and Bioethics, Nagoya University, Nagoya, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tsuchihashi
authors.affiliation: Department of Legal Medicine and Bioethics, Nagoya University, Nagoya, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ishii
mesh_terms: D000818:Animals; D002186:Cannabinoids / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D013287:Illicit Drugs; D007211:Indoles / Q000737:chemistry* / Q000652:urine; D007536:Isomerism; D008297:Male; D051379:Mice; D009281:Naphthalenes / Q000737:chemistry* / Q000652:urine; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D002186:Cannabinoids; D013287:Illicit Drugs; D007211:Indoles; D009281:Naphthalenes; C510548:4-hydroxyindole; C552597:1-pentyl-3-(1-naphthoyl)indole
keywords: GC-MS/MS; JWH-018 metabolites; positional isomers; synthetic cannabinoids