Identification of etamiphylline and metabolites in equine plasma and urine by accurate mass and liquid chromatography/tandem mass spectrometry

Etamiphylline camsylate (Millophylline V) was administered intravenously to two horses at a dose of 2.8 mg/kg. Urine and blood samples were taken up to 32 h post administration. Unhydrolyzed plasma and urine was extracted using solid phase extraction (SPE). The identity of the parent drug and metabolites was confirmed using a linear ion trap mass spectrometer and accurate mass analysis on an orbitrap mass spectrometer. Desethyletamiphylline (molecular weight 251) was the main metabolite observed in the urine and plasma samples and resulted from the N‐deethylation of etamiphylline. The second metabolite detected in urine and plasma resulted from the demethylation of etamiphylline (molecular weight 265). The third minor metabolite detected in urine was proposed to have resulted from a simultaneous N‐deethylation and demethylation of etamiphylline (molecular weight 238). Copyright © 2010 John Wiley & Sons, Ltd.     

采用UHPLC-MS和质量亏损过滤技术分析二苯乙烯苷在大鼠体内的代谢产物和代谢途径

目的:分析二苯乙烯苷在大鼠体内的代谢产物并推测代谢途径.方法:将雄性SD大鼠随机分为血浆组(n=3)、尿液组(n=3)、胆汁组(n=3)和组织组(n=9),各组大鼠均单次灌胃二苯乙烯苷200 mg/kg,分别收集给药后10、30 min和1、1.5、2、4 h的血浆,给药后0～6 h的尿液,给药后0～4 h的胆汁以及给...     

The use of in vitro technologies coupled with high resolution accurate mass LC-MS for studying drug metabolism in equine drug surveillance

The detection of drug abuse in horseracing often requires knowledge of drug metabolism, especially if urine is the matrix of choice. In this study, equine liver/lung microsomes/S9 tissue fractions were used to study the phase I metabolism of eight drugs of relevance to equine drug surveillance (acepromazine, azaperone, celecoxib, fentanyl, fluphenazine, mepivacaine, methylphenidate and tripelennamine). In vitro samples were analyzed qualitatively alongside samples originating from in vivo administrations using LC-MS on a high resolution accurate mass Thermo Orbitrap Discovery instrument and by LC-MS/MS on an Applied Biosystems Sciex 5500 Q Trap.Using high resolution accurate mass full-scan analysis on the Orbitrap, the in vitro systems were found to generate at least the two most abundant phase I metabolites observed in vitro for all eight drugs studied. In the majority of cases, in vitro experiments were also able to generate the minor in vivo metabolites and sometimes metabolites that were only observed in vitro. More detailed analyses of fentanyl incubates using LC-MS/MS showed that it was possible to generate good quality spectra from the metabolites generated in vitro. These data support the suggestion of using in vitro incubates as metabolite reference material in place of in vivo post-administration samples in accordance with new qualitative identification guidelines in the 2009 International Laboratory Accreditation Cooperation-G7 (ILAC-G7) document.In summary, the in vitro and in vivo phase I metabolism results reported herein compare well and demonstrate the potential of in vitro studies to compliment, refine and reduce the existing equine in vivo paradigm.     

基于分子网络图结合液质联用技术的莲子皮中生物碱类成分分析及含量测定

目的：利用分子网络图结合超高效液相色谱-四极杆-静电场轨道阱高分辨质谱法(UHPLC-Q-Exactive Orbitrap MS/MS)鉴定莲子皮中生物碱类成分,采用高效液相色谱法对莲子皮中甲基莲心碱含量进行测定。方法：选用ACQUITY UPLC HSS T3色谱柱(100 mm×2.1 mm,1.8μm),以乙腈(A)-0.1%氨水(B)为流动相,梯度洗脱(0～30 min,75%～40%B;30～40 min,40%～20%B),流速为0.2 mL·min^–1,柱温为30℃,进样量为2μL,正离子模式下进行数据采集,将采集得到的MS/MS数据导入全球天然产物社会分子网络(GNPS)构建分子网络图并进行可视化分析。选用Aglient ZORBAX XDB-C₁₈色谱柱(250 mm×4.6 mm,5μm),以乙腈-0.1%三乙胺(62∶38)为流动相等度洗脱,流速为1.0 mL·min^–1,检测波长为282 nm,柱温为25℃,进样量为20μL,对莲子皮中甲基莲心碱进行含量测定。结果：从莲子皮中共鉴别出14个生物碱...     

基于UHPLC-Q-Exactive Orbitrap MS技术分析经典名方芍药甘草汤的化学成分

目的  基于超高效液相色谱-四极杆-静电场轨道阱高分辨质谱联用(UHPLC-Q-Exactive Orbitrap MS)技术对经典名方芍药甘草汤的化学成分进行定性分析。方法  采用Thermo Scientific Hypersil GOLD C₁₈色谱柱(100 mm×2.1 mm, 1.7 μm), 以乙腈(A)-0.1%甲酸水溶液(B)为流动相梯度洗脱, 流速为0.3 mL·min-1, 柱温30 ℃。HESI-Ⅱ源正、负离子2种模式采集芍药甘草汤的一级、二级质谱数据。结果  根据高分辨质谱提供的精确分子量和碎片离子信息, 结合标准品比对、软件预测分析和相关文献报道对芍药甘草汤的化学成分进行分析。正、负离子模式下共鉴定出129个化合物, 包括82个黄酮类化合物,20个萜类化合物,10个酚类化合物, 7个香豆素类化合物和10个其他类化学成分。结论  利用UHPLC-Q-Exactive Orbitrap MS技术分析鉴定芍药甘草汤中的化学成分, 并初步归纳其各类主要化学成分的质谱裂解特点, 可为芍药甘草汤的质量控制以及药效物质基础的深入研究提供实验依据。      

异绿原酸C大鼠体内代谢产物鉴定

目的 分析大鼠灌胃给予异绿原酸C（4，5-二咖啡酰奎宁酸）后粪便、尿液及血浆内存在的代谢产物并推测其在大鼠体内的代谢途径。方法 大鼠按20 mg·kg^-1一次性灌胃给予异绿原酸C后，收集不同时间（段）的粪便、尿液及血浆，采用超高效液相色谱与Q-Exactive Plus Orbitrap 高分辨质谱技术（UPLC-Q-Exactive Plus Orbitrap MS）+质谱自带的软件联合的方法分析，对生物样品进行检测，并完成鉴定其代谢产物。结果 基于总离子流色谱图和一级二级质谱提供的分子离子和碎片离子等精确信息，最终从大鼠粪便、尿液和血浆中共发现11种成分，包括1个原型和10个代谢产物，涉及的代谢途径有水解、甲基化、氧化、还原、葡萄糖醛酸化、硫酸酯化等。结论 本实验建立的分析方法检测快速、结果准确、灵敏度高，符合生物基质样品分析相关要求，适用于大鼠粪便、尿液和血浆中异绿原酸C代谢产物的分析，为异绿原酸C的药效作用机制及药动学研究提供一定参考价值。     

Non‐targeted acquisition strategy for screening doping compounds based on GC‐EI‐hybrid quadrupole‐Orbitrap mass spectrometry: A focus on exogenous anabolic steroids

This is a first look at a non‐targeted screening method based on Orbitrap gas chromatography–mass spectrometry (GC–MS) technology for a large number of banned compounds in sports found in urine, including exogenous anabolic steroids, β‐agonists, narcotics, stimulants, hormone modulators, and diuretics. A simple sample preparation was processed in four steps: an enzymatic hydrolysis, liquid–liquid extraction, evaporation, and trimethylsilylation. All compounds were able to meet the World Anti‐Doping Agency's sensitivity criteria with mass accuracies less than 1 ppm and with sufficient points across the peak by running the Orbitrap GC–MS in full‐scan mode. In addition, we discuss our initial findings of using a full‐scan selected ion monitoring‐tandem mass spectrometry (SIM‐MS/MS) approach as a way to obtain lower detection limits and reach desirable selectivity for some exogenous anabolic steroids.     

High-performance liquid chromatography LTQ-Orbitrap mass spectrometry method for tomatidine and non-target metabolites quantification in organic and normal tomatoes

Tomatoes, members of the Solanaceae plant family, produce biologically active secondary metabolites, including glycoalkaloids and aglycons, which may have both adverse and beneficial biological effects. A new liquid chromatography method that utilized LTQ-Orbitrap MS was developed for the analysis of tomatidine, the main aglycon in tomatoes. Recoveries of tomatidine were >98.3% with the relative standard deviations (RSDs) below 6.1%. The limit of detection (LODs) was 0.0003?mg?kg^?1. The limit of quantitation (LOQs) is 0.001?mg?kg^?1. The linear range was between with 0.0025 and 1?mg?kg^?1 with an excellent correlation coefficient (R²) equal to 0.9990. Various tomato samples were analyzed and the level of tomatidine in the 11 samples analysed was higher in normal respect to organic tomatoes. The capability of the set-up Full Scan LTQ-Orbitrap MS method allowed us to quantified two non-target analytes. The m/z 1032 was identified as dehydrotomatine, confirmed through accurate mass studies (mass error in ppm equal to 1.5017) meanwhile m/z 902 as (Glc)₂–Gal-Tomatidine (β₁-Tomatine) (mass error in ppm equal to 2.0719).