title: Toxicokinetics of new psychoactive substances: plasma protein binding, metabolic stability, and human phase I metabolism of the synthetic cannabinoid WIN 55,212-2 studied using in vitro tools and LC-HR-MS/MS.
abstract: The new psychoactive substance WIN 55,212-2 ((R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo-[1,2,3-de]-1,4-benzoxazin-6-yl]-1-napthalenylmethanone) is a potent synthetic cannabinoid receptor agonist. The metabolism of WIN 55,212-2 in man has never been reported. Therefore, the aim of this study was to identify the human in vitro metabolites of WIN 55,212-2 using pooled human liver microsomes and liquid chromatography-high resolution-tandem mass spectrometry (LC-HR-MS/MS) to provide targets for toxicological, doping, and environmental screening procedures. Moreover, a metabolic stability study in pooled human liver microsomes (pHLM) was carried out. In total, 19 metabolites were identified and the following partly overlapping metabolic steps were deduced: degradation of the morpholine ring via hydroxylation, N- and O-dealkylation, and oxidative deamination, hydroxylations on either the naphthalene or morpholine ring or the alkyl spacer with subsequent oxidation, epoxide formation with subsequent hydrolysis, or combinations. In conclusion, WIN 55,212-2 was extensively metabolized in human liver microsomes incubations and the calculated hepatic clearance was comparably high, indicating a fast and nearly complete metabolism in vivo. This is in line with previous findings on other synthetic cannabinoids. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, D-66421, Homburg, Saar, Germany.
authors.forename: Marie
authors.initials: M
authors.lastname: Mardal
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Department of Environmental Health Sciences, Via La Masa 19, 20156, Milan, Italy.
authors.forename: Emma
authors.initials: E
authors.lastname: Gracia-Lor
authors.affiliation: Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, D-66421, Homburg, Saar, Germany.
authors.forename: Svenja
authors.initials: S
authors.lastname: Leibnitz
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Department of Environmental Health Sciences, Via La Masa 19, 20156, Milan, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Castiglioni
authors.affiliation: Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, D-66421, Homburg, Saar, Germany. markus.meyer@ki.se.|Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institute, Stockholm, Sweden. markus.meyer@ki.se.
authors.forename: Markus R
authors.initials: MR
authors.lastname: Meyer
mesh_terms: D048588:Benzoxazines / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics*; D001798:Blood Proteins / Q000737:chemistry / Q000378:metabolism*; D002186:Cannabinoids / Q000032:analysis / Q000138:chemical synthesis*; D002853:Chromatography, Liquid; D015198:Designer Drugs / Q000032:analysis / Q000138:chemical synthesis / Q000378:metabolism; D006801:Humans; D006900:Hydroxylation; D008862:Microsomes, Liver / Q000737:chemistry / Q000378:metabolism*; D009025:Morpholines / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics*; D009281:Naphthalenes / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics*; D010949:Plasma / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D066007:Toxicokinetics
chemical_list: D048588:Benzoxazines; D001798:Blood Proteins; D002186:Cannabinoids; D015198:Designer Drugs; D009025:Morpholines; D009281:Naphthalenes; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone; C037574:morpholine
keywords: LC-HR-MS/MS; designer drugs; human liver microsomes; metabolic stability; synthetic cannabinoids