Bioanalysis and Analytical Services Research Group, Neuropsychopharmacology Research Program, IMIM, Institut de Recerca Hospital del Mar, Barcelona, Spain.
J Chromatogr A. 2011 Jul 22;1218(29):4727-37. doi: 10.1016/j.chroma.2011.05.073. Epub 2011 May 27.
Toremifene is a selective estrogen receptor modulator included in the list of prohibited substances in sport by the World Anti-doping Agency. The aim of the present study was to investigate toremifene metabolism in humans in order to elucidate the structures of the most abundant urinary metabolites and to define the best marker to detect toremifene administration through the analysis of urine samples. Toremifene (Fareston) was administered to healthy volunteers and the urine samples were subjected to different preparation methods to detect free metabolites as well as metabolites conjugated with glucuronic acid or sulphate. Urinary extracts were analyzed by LC-MS/MS with triple quadrupole analyzer using selected reaction monitoring mode. Transitions for potential metabolites were selected by using the theoretical M+H as precursor ion and m/z 72 or m/z 58 as product ions for N,N-dimethyl and N-desmethyl metabolites, respectively. Toremifene and 20 metabolites were detected in excretion study samples, excreted free or conjugated with glucuronic acid or sulphate. Structures for most abundant phase I metabolites were proposed using accurate mass measurements performed by QTOF MS, based on fragmentation pattern observed for those metabolites available as reference standards. Several metabolic pathways including mono- and di-hydroxylation, N-desmethylation, hydroxymethylation, oxidation, dehalogenation and combinations were proposed. All metabolites were detected up to one month after toremifene administration; the most abundant metabolites were detected in the free fraction and they were metabolites resulting from dehalogenation. Several of the metabolites elucidated in this work have not been reported until now in the scientific literature.
枸橼酸他莫昔芬是世界反兴奋剂机构（WADA）禁用清单中的一种选择性雌激素受体调节剂。本研究旨在研究枸橼酸他莫昔芬在人体内的代谢情况，以阐明最主要的尿代谢物的结构，并通过尿液样本分析来确定检测枸橼酸他莫昔芬给药的最佳标志物。枸橼酸他莫昔芬（法乐通）被给予健康志愿者，对尿液样本进行了不同的处理方法，以检测游离代谢物以及与葡萄糖醛酸或硫酸盐结合的代谢物。采用 LC-MS/MS 分析，三重四极杆分析仪采用选择反应监测模式。通过使用理论 M+H作为前体离子和 m/z 72 或 m/z 58 作为 N,N-二甲基和 N-去甲基代谢物的产物离子，选择潜在代谢物的跃迁。在排泄研究样品中检测到枸橼酸他莫昔芬和 20 种代谢物，以游离或与葡萄糖醛酸或硫酸盐结合的形式排泄。使用 QTOF MS 进行精确质量测量，基于可作为参考标准的那些代谢物的碎片模式，提出了大多数丰度的 I 期代谢物的结构。提出了包括单加氧和二加氧、N-去甲基化、羟甲基化、氧化、脱卤和组合在内的多种代谢途径。在枸橼酸他莫昔芬给药后一个月内检测到所有代谢物；最主要的代谢物在游离部分检测到，它们是脱卤代谢物。在这项工作中阐明的几种代谢物直到现在才在科学文献中报道。
