Department of Chemistry, Council of Forensic Medicine, Istanbul, Turkey.
J Anal Toxicol. 2021 Jan 21;44(9):976-984. doi: 10.1093/jat/bkaa017.
MDMB-4en-PINACA (methyl (S)-3,3-dimethyl-2-(1-(pent-4-en-1-yl)-1H-indazole-3-carboxamido)butanoate) is a recently emerged synthetic cannabinoid in Turkey. MDMB-4en-PINACA was detected in herbal material investigated by the Council of Forensic Medicine, Istanbul Narcotics Department in Turkey in April 2019. MDMB-4en-PINACA was added to the drug abuse list and quickly reported in biological samples after its first detection. In this study, the in vitro metabolism of MDMB-4en-PINACA was investigated by using a pooled human liver microsomes (HLMs) assay and liquid chromatography-high-resolution mass spectrometry (LC-HRMS). MDMB-4en-PINACA (5 μmol/L) was incubated with HLMs for up to 1 h, and the metabolites were identified using LC-HRMS and software-assisted data mining. The in vivo metabolism was investigated by the analysis of 22 authentic urine samples and compared to the data received from the in vitro metabolism study. Less than 7.5% of the MDMB-4en-PINACA parent compound remained after the 1 h incubation. We identified 14 metabolites, which were formed via double bond oxidation, ester hydrolysis, N-dealkylation, hydroxylation, dehydrogenation and further oxidation to N-pentanoic acid or a combination of these reactions in vitro. In 10 urine samples (total n = 22), MDMB-4en-PINACA was detected as the parent drug. Three of the identified main metabolites, double bond oxidation in combination with ester hydrolysis and hydroxylation metabolite (M3), MDMB-4en-PINACA butanoic acid (M14) and monohydroxypentyl-MDMB-4en-PINACA (M12), were suggested as suitable urinary markers. In vitro screening of 2,150 authentic urine samples for these identified MDMB-4en-PINACA metabolites resulted in 56 cases of confirmed MDMB-4en-PINACA consumption (2.6%).
MDMB-4en-PINACA（甲基（S）-3,3-二甲基-2-（1-（戊-4-烯-1-基）-1H-吲哚-3-甲酰胺基）丁酯）是土耳其最近出现的一种合成大麻素。2019 年 4 月，土耳其法医委员会伊斯坦布尔缉毒处对草药材料进行调查时发现了 MDMB-4en-PINACA。MDMB-4en-PINACA 被添加到药物滥用清单中，并在首次检测后迅速在生物样本中报告。在这项研究中，使用混合人肝微粒体（HLMs）测定和液相色谱-高分辨率质谱（LC-HRMS）研究了 MDMB-4en-PINACA 的体外代谢。将 MDMB-4en-PINACA（5 μmol/L）与 HLMs 温育长达 1 小时，并使用 LC-HRMS 和软件辅助数据挖掘鉴定代谢物。通过分析 22 份真实尿液样本研究了体内代谢，并与体外代谢研究的数据进行了比较。孵育 1 小时后，不到 7.5%的 MDMB-4en-PINACA 母体化合物仍然存在。我们鉴定了 14 种代谢物，这些代谢物是通过双键氧化、酯水解、N-脱烷基化、羟化、脱氢和进一步氧化成戊酸或这些反应的组合在体外形成的。在 10 份尿液样本（总共 n=22）中，检测到 MDMB-4en-PINACA 作为母体药物。在所鉴定的主要代谢物中，有 3 种（双键氧化与酯水解和羟化代谢物（M3）、MDMB-4en-PINACA 丁酸（M14）和单羟戊基-MDMB-4en-PINACA（M12））被建议作为合适的尿液标志物。对 2,150 份真实尿液样本进行体外筛选，结果显示 56 例 MDMB-4en-PINACA 消费得到证实（2.6%）。
