{"title":"Metabolic characteristic profiling of 1-amino-3,3-dimethyl-1-oxobutan-2-yl-derived indole and indazole synthetic cannabinoids in vitro","authors":"","doi":"10.1016/j.jpba.2024.116385","DOIUrl":null,"url":null,"abstract":"<div><p>Characterizing the metabolic profiles of synthetic cannabinoids (SCs), a type of new psychoactive substances, is of particular importance for forensic detection and analysis. Although the metabolism of individual SCs derived from 1-amino-3,3-dimethyl-1-oxobutan-2-yl (ADB-SCs) has been reported, their metabolites also undergo a continuous change and combination of their tail and core regions. Therefore, elucidating the metabolic characteristics and effects of these structures is essential to enhance our understanding. In this study, the human liver microsome was used as the model for studying the <em>in vitro</em> phase I metabolism of 12 ADB-SCs, and the metabolites obtained were analyzed using ultra-high performance liquid chromatography–tandem four-level rod-electrostatic field orbital ion trap mass spectrometry to determine type, structure, and relative contents. The results indicated that hydroxylation and <em>N</em>-dealkylation were the major metabolic pathways in 12 ADB-SCs. The effects of the core and tail on the metabolism of these ADB-SCs were studied using theoretical calculations. For <em>N</em>-dealkylation metabolism, the strong electron-withdrawing conjugative effect of the –N= moiety in the pyrazole ring, steric hindrance of the tail, and electronic effect of substituents on the tail significantly affected metabolism. Further, it changed the relative contents of <em>N</em>-dealkylation metabolites. For hydroxylation, the reaction types were inconsistent at different parts. For instance, the phenyl group of the core is electrophilic, and its electron cloud density determines whether the phenyl group can be hydroxylated at the specific metabolic sites. Meanwhile, hydroxylation of the neopentyl moiety of the linked group involves the oxidation of aliphatic C–H bonds, whereas amide–hydroxylamine tautomerism affects hydroxylation metabolism. When the alkyl chain in the tail contains functional groups (such as –F and >C<img>C<), oxidative defluorination or dihydrodiol metabolites are produced. Taken together, we systematically determined d the effect of functional groups in the core and tail of ADB-SCs on their metabolism, validating confirmed the feasibility of ADB-SC metabolism prediction based on their structural characteristics.</p></div>","PeriodicalId":16685,"journal":{"name":"Journal of pharmaceutical and biomedical analysis","volume":null,"pages":null},"PeriodicalIF":3.1000,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of pharmaceutical and biomedical analysis","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0731708524004254","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, ANALYTICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Characterizing the metabolic profiles of synthetic cannabinoids (SCs), a type of new psychoactive substances, is of particular importance for forensic detection and analysis. Although the metabolism of individual SCs derived from 1-amino-3,3-dimethyl-1-oxobutan-2-yl (ADB-SCs) has been reported, their metabolites also undergo a continuous change and combination of their tail and core regions. Therefore, elucidating the metabolic characteristics and effects of these structures is essential to enhance our understanding. In this study, the human liver microsome was used as the model for studying the in vitro phase I metabolism of 12 ADB-SCs, and the metabolites obtained were analyzed using ultra-high performance liquid chromatography–tandem four-level rod-electrostatic field orbital ion trap mass spectrometry to determine type, structure, and relative contents. The results indicated that hydroxylation and N-dealkylation were the major metabolic pathways in 12 ADB-SCs. The effects of the core and tail on the metabolism of these ADB-SCs were studied using theoretical calculations. For N-dealkylation metabolism, the strong electron-withdrawing conjugative effect of the –N= moiety in the pyrazole ring, steric hindrance of the tail, and electronic effect of substituents on the tail significantly affected metabolism. Further, it changed the relative contents of N-dealkylation metabolites. For hydroxylation, the reaction types were inconsistent at different parts. For instance, the phenyl group of the core is electrophilic, and its electron cloud density determines whether the phenyl group can be hydroxylated at the specific metabolic sites. Meanwhile, hydroxylation of the neopentyl moiety of the linked group involves the oxidation of aliphatic C–H bonds, whereas amide–hydroxylamine tautomerism affects hydroxylation metabolism. When the alkyl chain in the tail contains functional groups (such as –F and >CC<), oxidative defluorination or dihydrodiol metabolites are produced. Taken together, we systematically determined d the effect of functional groups in the core and tail of ADB-SCs on their metabolism, validating confirmed the feasibility of ADB-SC metabolism prediction based on their structural characteristics.
期刊介绍:
This journal is an international medium directed towards the needs of academic, clinical, government and industrial analysis by publishing original research reports and critical reviews on pharmaceutical and biomedical analysis. It covers the interdisciplinary aspects of analysis in the pharmaceutical, biomedical and clinical sciences, including developments in analytical methodology, instrumentation, computation and interpretation. Submissions on novel applications focusing on drug purity and stability studies, pharmacokinetics, therapeutic monitoring, metabolic profiling; drug-related aspects of analytical biochemistry and forensic toxicology; quality assurance in the pharmaceutical industry are also welcome.
Studies from areas of well established and poorly selective methods, such as UV-VIS spectrophotometry (including derivative and multi-wavelength measurements), basic electroanalytical (potentiometric, polarographic and voltammetric) methods, fluorimetry, flow-injection analysis, etc. are accepted for publication in exceptional cases only, if a unique and substantial advantage over presently known systems is demonstrated. The same applies to the assay of simple drug formulations by any kind of methods and the determination of drugs in biological samples based merely on spiked samples. Drug purity/stability studies should contain information on the structure elucidation of the impurities/degradants.