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%).

中文翻译：

---

最近出现的合成MDMB-4en-PINACA的体外I期代谢及其在人尿液样品中的检测。

MDMB-4en-PINACA（甲基（S）-3,3-二甲基-2-（1-（戊-4-烯-1-基）-1 H-吲唑-3-甲酰胺基）丁酸酯）是最近出现的合成物大麻在土耳其。2019年4月，在土耳其伊斯坦布尔禁毒局法医委员会调查的草药材料中检测到MDMB-4en-PINACA.MDMB-4en-PINACA被添加到药物滥用列表中，并在首次发现后迅速在生物样品中报告。在这项研究中，通过使用合并的人肝微粒体（HLM）分析和液相色谱-高分辨率质谱（LC-HRMS）研究了MDMB-4en-PINACA的体外代谢。将MDMB-4en-PINACA（5μmol/ L）与HLM孵育长达1小时，并使用LC-HRMS和软件辅助数据挖掘对代谢物进行鉴定。的在体内代谢物通过的22个真实尿样分析研究并比较从接收到的数据在体外代谢研究。温育1小时后，剩下不到7.5％的MDMB-4en-PINACA母体化合物。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，羟基化，脱氢和进一步氧化成N-戊酸或体外这些反应的组合形成的。在10个尿液样本中（总n = 22），则将MDMB-4en-PINACA检测为母体药物。建议使用三种已鉴定出的主要代谢物，双键氧化结合酯水解和羟基化代谢物（M3），MDMB-4en-PINACA丁酸（M14）和单羟基戊基-MDMB-4en-PINACA（M12）作为合适的尿液标记物。对这些鉴定出的MDMB-4en-PINACA代谢产物进行了2150份真实尿液样品的体外筛选，结果证实有56例MDMB-4en-PINACA消费量（2.6％）。