Detection of bioactive peptides including gonadotrophin‐releasing factors (GnRHs) in horse urine using ultra‐high performance liquid chromatography–high resolution mass spectrometry (UHPLC/HRMS)

The use of bioactive peptides as a doping agent in both human and animal sports has become increasingly popular in recent years. As such, methods to control the misuse of bioactive peptides in equine sports have received attention. This paper describes a sensitive accurate mass method for the detection of 40 bioactive peptides and two non‐peptide growth hormone secretagogues (< 2 kDa) at low pg/mL levels in horse urine using ultra‐high performance liquid chromatography‐high resolution mass spectrometry (UHPLC/HRMS). A simple mixed‐mode cation exchange solid‐phase extraction (SPE) cartridge was employed for the extraction of 42 targets and/or their in vitro metabolites from horse urine. The final extract was analyzed using UHPLC/HRMS in positive electrospray ionization (ESI) mode under both full scan and data independent acquisition (DIA, for MS²). The estimated limits of detection (LoD) for most of the targets could reach down to 10 pg/mL in horse urine. This method was validated for qualitative detection purposes. The validation data, including method specificity, method sensitivity, extraction recovery, method precision, and matrix effect were reported. A thorough in vitro study was also performed on four gonadotrophin‐releasing factors (GnRHs), namely leuprorelin, buserelin, goserelin, and nafarelin, using the S9 fraction isolated from horse liver. The identified in vitro metabolites have been incorporated into the method for controlling the misuse of GnRHs. The applicability of this method was demonstrated by the identification of leuprorelin and one of its metabolites, Leu M4, in urine obtained after intramuscular administration of leuprorelin to a thoroughbred gelding (castrated horse).     

UHPLC/MSn多模式复合测定玉屏风复方提取物及制剂中13种化学成分含量

目的 建立测定玉屏风提取物中多组分的UHPLC/MSⁿ定量方法。方法 查阅文献,根据玉屏风制剂及其组方各单味药的药效学、药动学分析,选择升麻素苷、毛蕊异黄酮苷、升麻素、5-O-甲基维斯阿米醇苷、芒柄花苷、亥茅酚苷、芒柄花素、黄芪甲苷Ⅳ、白术内酯Ⅲ、黄芪皂苷Ⅱ、黄芪皂苷Ⅰ、白术内酯Ⅱ、白术内酯Ⅰ等13个化合物作为玉屏风复方的指示性成分进行质量控制。采用ACQUITY UPLC^® HSS T3色谱柱,乙腈-0.1%甲酸水溶液为流动相进行梯度洗脱,流速0.5 mL/min。结果 在所建立的液相色谱条件下,13种成分的专属性良好,无干扰峰,各成分在线性范围内具有良好的线性关系;回收率为95%~105%,RSD均小于3%。结论 UHPLC/MSⁿ定量方法简便、快速、准确,有助于玉屏风复方的质量控制。     

葛根芩连汤干预2型糖尿病前期大鼠的代谢机制研究

目的探讨葛根芩连汤对高脂诱导的2型糖尿病大鼠预防作用的代谢机制。方法将SD大鼠随机分为正常组(8只)和高脂造模组(40只),分别使用基础饲料和高脂饲料喂养12周。高脂造模组大鼠产生胰岛素抵抗(IR)后,将高脂造模组大鼠再随机分为模型组及葛根芩连汤低、中、高剂量组(1.65、4.96、14.86 g·kg-1),每组8只。模型组及不同剂量给药组继续给予高脂饲料喂养,给药组给予不同剂量的葛根芩连汤进行干预,灌胃给药,给药体积为10 mL·kg-1,每天1次,连续16周。检测大鼠空腹血糖值及空腹胰岛素含量,计算IR指数;使用超高效液相色谱-四级杆飞行时间串联质谱(UHPLC/Q-TOF-MS)结合多元分析方法,分析大鼠血清中的内源性代谢物及其变化差异,寻找葛根芩连汤干预IR大鼠及预防2型糖尿病的潜在生物标记物。结果高脂饲料喂养12周后,与正常组比较,造模组大鼠的IR指数明显升高(P<0.05),血糖无明显变化(P>0.05)。给药16周后,与正常组比较,模型组大鼠的IR指数及血糖值均显著升高(P<0.05,P<0.01);与模型组比较,葛根芩连汤低、中剂量组大鼠的IR指数显著降低(P<0.01),葛根芩连汤高剂量组的IR指数无明显变化(P>0.05);葛根芩连汤低剂量组的空腹血糖值明显降低(P<0.05),而葛根芩连汤中、高剂量组的空腹血糖值无明显变化(P>0.05)。大鼠血清代谢组分析鉴定共得到4种潜在代谢标志物,分别是Hippuric acid(马尿酸)、12-Ketodeoxycholic acid(12-去氧胆酸)、3-Oxo-4,6-choladienoic acid和LysoPC[20∶4(5Z,8Z,11Z,14Z)](溶血磷脂酰胆碱,LPC)。结论葛根芩连汤可以降低IR大鼠的胰岛素抵抗指数,同时可预防血糖升高,其机制可能与调节胆汁酸代谢、磷脂代谢以及肠道菌群代谢有关。     

Development and validation of a rapid and sensitive UHPLC–MS/MS method for the determination of paliperidone in beagle dog plasma

In order to evaluate the pharmacokinetic profile of paliperidone extended-release tablets in vivo, a simple and rapid ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method was developed and validated for the determination of paliperidone in beagle dog plasma. Paliperidone and diazepam (internal standard) were extracted from plasma samples with diethyl ether, and then separated on a C₁₈ column (2.1 × 50 mm, 2.6 μm) under gradient elution with methanol–0.1% formic acid at a flow rate of 0.3 ml/min. The compounds were detected using a triple-quadrupole mass spectrometer equipped with an electrospray ionization (ESI) source. The validated method was linear over the concentration range of 1.00–1000.00 ng/ml and the lower limit of quantitation was 1.00 ng/ml. The intra-day and inter-day precision values were not more than 15% (relative standard deviation < 20% at low levels), while the accuracy was within ±10% of nominal values. The validated UHPLC–MS/MS method was successfully applied to an oral pharmacokinetic study of paliperidone extended-release tablets in a beagle dog.     

Rapid profiling and identification of triterpenoid saponins in crude extracts from Albizia julibrissin Durazz. by ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry

Ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/ESI-Q-TOF-MS/MS) was applied to separate and identify triterpenoid saponins in crude extract from the stem bark of Albizia julibrissin Durazz. The molecular weights were determined by comparing quasi-molecular ions [M+NH(4)](+) in positive mode and [M-H](-) and [M-2H](2-) ions in negative mode. The MS/MS spectra of the [M-H](-) ions for saponins provided a wealth of structural information related to aglycone skeletons, sugar types and linked sequence. On the basis of the fragmentation behavior of known saponins isolated before, saponins from this plant were identified, even though references were not available. As a result, a total of twenty-eight saponins in the crude extract were identified, which all had a common basic skeleton of the triterpene oleanolic acid and eight of them were new compounds.     

超高效液相色谱法测定紫杉肽中紫杉醇含量

目的建立超高效液相色谱法（UHPLC）测定聚二肽紫杉醇（紫杉肽）注射制剂中紫杉醇含量。方法紫杉肽注射制剂以蒸馏水溶解,经2.0 mol/L氢氧化钠溶液降解处理后,通过对紫杉醇降解产物的测定,间接标定紫杉肽注射制剂中紫杉醇的含量。采用Agilent SB C18（2.1 mm ×50 mm,1.8μm）色谱柱,流动相为乙腈-水（10∶90,V/V）,流速0.2 ml/min,检测波长240 nm（参比波长360 nm）,柱温40℃（±0.5℃）,自动进样器温度15℃（±0.5℃）,进样体积2μl。结果紫杉醇浓度在0.31～5.00 mg/ml范围内与其降解产物的峰面积呈现良好的线性关系（r=0.9992,n=5）。不同批次紫杉肽注射制剂中每支含紫杉醇的量在26.77～33.19 mg范围内。结论本方法准确、快速,重现性好,适用于紫杉肽注射制剂中紫杉醇含量分析。     

UHPLC-Q-TOF／MS技术应用于中药旱莲草化学成分研究

目的通过超高效液相色谱-四极杆飞行时间串联质谱（UHPLC-Q-TOF/MS）对中药旱莲草的化学成分进行系统、全面研究。方法采用Agilent SB-C18（2.1 mm×100 mm,1.8μm）柱,流动相为乙腈-甲酸溶液系统梯度洗脱,质谱采用ESI正离子模式,分别对桂林阳朔、桂林荔蒲、湖南邵阳、南宁和湖北襄樊五个产地的旱莲草药材进行分析。结果该方法共鉴别出旱莲草中29个化学成分。结论本实验为建立旱莲草药材的质量控制标准提供了参考依据。     

Ultra high performance liquid chromatography-tandem mass spectrometry vs. commercial immunoassay for determination of vancomycin plasma concentration in children. Possible implications for everyday clinical practice

Background: Vancomycin therapeutic drug monitoring (TDM) is necessary for effective and safetherapy. The aim of the this paper was to develop a specific and robust ultra high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method for vancomycin quantification starting from low plasma volumes to be applied for the routine TDM in children.

Methods: Samples from children receiving intravenous vancomycin were analysed using a TSQ Quantum Access MAX Triple Quadrupole system coupled with an Accela 1250 UHPLC system after a rapid protein precipitation. Gradient separation chromatography was carried out using a Hypersil GOLD aQ C18 column (50 × 2.1 mm, particle size 1.9 μm). Method performance was validated following international guidelines.

Results: UHPLC–MS/MS allowed a rapid and specific quantification of vancomycin over the range 0.1–128 μg/mL from 50 μL of plasma with high reproducibility and accuracy in the absence of matrix effect. The comparison with the commercial immunoassay performed on 138 samples demonstrated the presence of a proportional bias. The concentrations of vancomycin measured with immunoassay were found to be 4.5% (95% CI: 1.3–7.7) higher than those determined with UHPLC–MS/MS. Importantly, a clinical discordance was found in about 10% of samples analysed.

Conclusions: This new UHPLC–MS/MS method is accurate and specific for the measurement of vancomycin starting from small (50 μL) plasma volumes. The use of UHPLC–MS/MS is recommended to prevent a misclassification of therapeutic or toxic vancomycin levels in paediatrics.     

三叶青叶指纹图谱研究及8种酚类成分含量测定

采用超高效液相色谱建立三叶青叶指纹图谱,并同时测定8种酚类成分(新绿原酸、绿原酸、隐绿原酸、异荭草苷、荭草苷、牡荆素鼠李糖苷、牡荆苷、异牡荆苷)的含量,为三叶青叶质量评价提供依据。采用UHPLC法,Welch UHPLC Ultimate XB-C18色谱柱(4.6 mm×150 mm,2.7μm),流动相为乙腈-0.1%甲酸(含5%甲醇)水梯度洗脱,流速0.4 m L·min~(-1),柱温30℃,采用国家药典委员会"相似度评价软件2004AB"处理分析,建立41批不同产地三叶青叶的指纹图谱,共标定15个共有峰并对不同产地进行聚类分析,然后选择其中8个主要的酚类成分作为定量指标,建立UHPLC同时测定8种主要酚类成分含量的方法,经方法学验证该研究建立的三叶青叶指纹图谱和8种酚类成分含量测定方法简便有效、灵敏、准确,可为综合评价三叶青叶的质量提供参考。