Chemical Components of Achyranthes bidentata Leaves by Ultra High Performance Liquid Chromatography-Mass Spectrometry

[Objectives] To study the chemical components and relative content of Achyranthes bidentata leaves and provide a scientific basis for further development and utilization of A. bidentata leaves.[Methods] The chemical components of A. bidentata leaves were rapidly analyzed using the ultra high performance liquid chromatography-time of flight-high resolution mass spectrometry (UHPLC-TOF-MS).[Results] Thirty eight chemical compounds were identified in samples of A. bidentata leaves collected from Wen County of Henan Province, in which seven chemical compounds had the relative content higher than 5%, linoleic acid reached 25.7% and inokosterone A reached 13.8%.[Conclusions] A. bidentata leaves contain many kinds of chemical compounds. This study is expected to provide a certain basis for further extraction of linoleic acid and inokosterone A.

Analysis of hydroxylated polybrominated diphenyl ethers in plant samples using ultra performance liquid chromatography-mass spectrometry

A method was developed for the analysis of hydroxylated brominated diphenyl ethers (OH-PBDEs) in plant samples using an ultra performance liquid chromatography-triple quadrupole mass spectrometer (UPLC-ESI-MS/MS) in negative mode. Plant samples were extracted and cleaned up through florisil column, resolved on a 100 mm C18 column with linear gradient elution and detected by mass spectrometry in multiple reaction monitoring (MRM) mode. The method provided good recoveries rang- ing from 68.2% to 94.6%, relative standard deviation (RSD) in the range of 3.2% - 9.1%, and limits of quantification (LOQ) defined as the signal-to-noise ratio of 10 of 0.3-2.1 ng/g. It allowed a fast separation and sensitive quantification of the isomers and homologues of seven OH-PBDE congeners 2′-OH-BDE-3, 3′-OH-BDE-7, 4′-OH-BDE-17, 3′-OH-BDE-28, 3-OH-BDE-47, 5-OH-BDE-47 and 6-OH-BDE-47. The method was successfully applied to identify and quantify the formation of hydroxylat- ed metabolites in alfalfa exposed to BDE-209. Five OH-PBDEs were detected in plant tissues, and more congeners were found in roots than in shoots. To our knowledge, this work represents the first attempt to validate UPLC-MS/MS method to quantify OH-PBDEs in plant samples without derivatization.

Determination of Steroid Hormone Residues in Fish Tissues Using Gel Permeation Chromatography and Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A highly sensitive method was developed for the simultaneous determination of 8 steroid hormones in high-fat fish tissues using ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The 8 steroid hormones were extracted from the tissues with diethyl ether.Differing from other common purification methods,the extract solutions were cleaned by gel permeation chromatography(GPC) using ethyl acetate-cyclohexane solution(1:1,v/v) as the mobile phase.The separation of target compounds was carried out by a BEH C18 column and a gradient elution consisting of acetonitrile and 0.2% aqueous formic acid(v/v).The compounds were detected under the multiple reaction monitoring(MRM) mode and quantified with external standard method.This method was validated with respect to linearity,specificity,accuracy and precision.A linearity with correlation coefficient larger than 0.995 was achieved in the range of 0.5 to 50 ng m L^(-1).The average recoveries at the spiked levels of 1.0,5.0,and 10.0 μg kg^(–1) varied between 81.7% and 90.8%,with the relative standard deviations(n=5) ranged from 3.50% to 10.0%.The limit of quantification(LOQ) for 8 steroid hormones ranged from 0.2 to 1.5 μg kg^(-1).It was concluded that this method can be successfully applied for the determination of 8 steroid hormones in complicated matrices including high-fat fish tissues.

Simultaneous Determination of Bisphenols and Alkylphenols in Water by Solid Phase Extraction and Ultra Performance Liquid Chromatography-tandem Mass Spectrometry

To establish an analytical method for determination of four bisphenols （BPA, BPB, BPF, and BPS） and two alkylphenols （4-n-OP, 4-n-NP） in water by ultra performance liquid chromatography- tandem mass spectrometry （UPLC/MS/MS）. The water samples were extracted and condensed with solid-phase extraction （SPE） using C18 cartridges and eluted by acetonitrile. Separation was carried out with Acquity BEH C8 column and detection were performed by UPLC/MS/MS. Quantification was calculated by using the internal standard BPA-d16 and 4-n-NP-d8. The linear correlation coefficients of these compounds in the range of 1.0-100.0μg/L were all over 0.999. The minimum detectable concentrations were 0.75-1.0 ng/L, and the recoveries ranged from 87.0% to 106.9%.

Uncertainty Evaluation of Determination of Microcystin MC-LR in Environmental Samples by Solid Phase Extraction-Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

To assess uncertainty of determination of MC-LR in environmental samples by solid phase extraction- ultra performance liquid chromatography- tandem mass spectrometry,the sources of the uncertainty were evaluated firstly,and the expanded uncertainty was calculated finally.The results show that when MC-LR concentration in the water samples was 0.50 μg/L,the expanded uncertainty was 0.00628 μg/L(k=2).

Simultaneous Determination of Ultraviolet Absorbers and Antibacterial Agents in Textiles by Ultra-High Performance Liquid Chromatography/Orbitrap High Resolution Mass Spectrometry

This paper reported a new analytical method for the simultaneous determination of seven benzotriazole ultraviolet absorbers and seven antibacterial agents in textiles. After ultrasonic extraction for the textile samples in methanol, the solutions were analyzed by ultra-high performance liquid chromotagraphy/orbitrap high resolution mass spectrometry (UPLC/Orbitrap HRMS). It showed that a good chromatographic separation for these target compounds was achieved by a Hypersil GOLD column (100 mm × 2.1 mm × 1.9 μm) with a gradient elution of methanol and 0.1% aqueous formic acid solution (containing 0.5 mmol/L ammonium acetate). Triclosan and 4-chloro-3,5-dimethyl phenol (PCMX) were detected by the orbitrap HRMS in an electrospray ionization (ESI) negative mode while the other twelve target compounds were detected by orbitrap HRMS in ESI positive mode. Full scan experiment was performed over the range from m/z 100 to m/z 500. These target compounds were routinely detected with mass accuracy below 2 × 10-6 (2 ppm) at the optimized conditions. The results showed that the limits of detection (LODs) were in the range from 0.1 to 0.3 μg/kg. The blank samples were spiked at three levels and their average recoveries varied from 80.5% to 96.3% while the relative standard deviation (RSD) changed from 3.2% to 9.9%. The present method was also applied for the determination of those ultraviolet absorbers and antibacterial agents in the commercial textiles.

Rapid Determination of Three Kinds of Microcystins in Environmental Water Samples by Disk SPE-Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A method of rapidly detecting three kinds of microcystins( MCs) in environmental water samples by using disk SPE- ultra high performance liquid chromatography- tandem mass spectrometry( UPLC- MS / MS) was established. Firstly,environmental water samples were extracted by disk SPE column( C_(18)),and three kinds of MCs were separated by Waters BEH C_(18) chromatographic column with acetonitrile- 0. 2% formic acid solution as the mobile phase. After the gradient elution separation,the external standard method was used for quantitative and qualitative analysis under MRM of UPLC- MS / MS. The results showed that the three kinds of MCs in the range of 0. 05- 10 μg / L showed good linear relation,and the correlation coefficients were higher than 0. 999 4,while the method detection limit was 0. 04 ng / L. Under 0. 1,1,and 5 μg / L standard addition for the same environmental sample,the average recovery was 82. 8%- 108. 8%,and the relative standard deviation of determination results was2. 1%- 10. 1%( n = 6). This method is rapid,sensitive and accurate,so it can be effectively applied in the monitoring of MCs in environmental water samples.

Determination of thyreostats in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry

Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in positive electrospray ionization mode.Extraction and clean-up were achieved using a ChemElut cartridge with tert-butyl methyl ether,without a derivatization step.Separation was achieved on an Acquity UPLC SS T3 column.The mobile phase was acetonitrile and water containing 0.2%(v/v)formic acid.The mass spectrometer was operated in multiple reaction monitoring mode.Urine samples were spiked with TS solution at levels corresponding to 5,10,15,and 20μg/L.The accuracy(internal standard corrected)ranged from 92%to 107%,with a repeatability precision(relative standard deviation,RSD)less than 15%for all five analytes.The RSDs within-laboratory reproducibility was less than 26%.The decision limits(CCα)and detection capabilities(CCβ)were obtained from a calibration curve and were in the ranges of 3.1-6.1μg/L and 4.0-7.4μg/L,respectively.The CCαand CCβvalues were below the recommended concentration,which was set at 10μg/L.The results show that the described method is suitable for the direct detection of TSs in bovine urine.This method can also be used to determine TSs in porcine urine.

Determination of Oleuropein in Cosmetics by Ultra Performance Liquid Chromatography-Triple Quadrupole Tandem Mass Spectrometry

An ultrahigh performance liquid chromatography-triple quadrupole tandem mass spectrometry(UPLC-MS/MS)was established to quickly and accurately determine the content of oleuropein in cosmetics.The samples were extracted with methanol-aqueous solution,and the mobile phase with methanol-formic acid solution(0.1 mol/L)=40∶60 was separated by Agilent ZORBAX Eclipse Plus C18(2.1 mm×50 mm×1.8μm-Micron)column temperature 30℃,flow rate 0.3 mL/min.The MS end was detected by electrospray negative mode ionization(ESI-)and multiple reaction monitoring(MRM)mode.The results show a good linear relationship in the range of 0.002~5 mg/L,with a correlation coefficient R2 of 0.999,5.Method recovery range from 84.2%~107.6%and the relative standard deviation RSD is 5.8%.The detection time is 5 min,the detection limit is 0.000,6 mg/L,and the limit of quantification is 0.002 mg/L.This method has the advantages of convenient operation,low quantification limit,high precision and good repeatability,and is suitable for measuring the content of oleuropein in many kinds of cosmetics.

Lysophosphatidylcholine Biomarkers of Lung Cancer Detected by Ultra-performance Liquid Chromatography Coupled with Quadrupole Time-of-flight Mass Spectrometry

Centrifugal ultrafiltration after methanol extraction of whole plasma was used as an optimal condition for the preparation of blood plasma before metabonomic studies. The plasma samples from 102 lung cancer patients and 34 healthy volunteers were prepared with this approach. With ultra-performance liquid chromatography（UPLC） coupled with quadrupole time-of-flight mass spectrometry（Q-TOF MS） analysis, the samples were investigated in order to find potential disease biomarkers. After data acquisition, orthogonal signal correction partial least squares models were built to differentiate the healthy volunteers from lung cancer patients and to identify metabolites that showed significantly different expression between the two groups. Several metabolite ions were identified as potential biomarkers according to the variable importance in the project（VIP） value in both ion modes. Five lysophosphatidylcholines were further identified as specifically lysoPC 16：0, isomer of lysoPC 16：0, lysoPC 18：0, lysoPC 18：1 and lysoPC 18：2. These results suggest that UPLC coupled with Q-TOF MS is an effective technique for the analysis of plasma metabolites in metabonomic studies.

A Validated Liquid Chromatography-Mass Spectrometry Method for the Detection and Quantification of Oxidative Metabolites of 2,2',4,4'-Tetrabromodiphenyl Ether in Rat Hepatic Microsomes

In the present study, we developed and validated an analytical method using ultra performance liquid chromatography-mass spectrometry (UPLC/MS) for the quantitative determination of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) metabolism by rat hepatic microsomes. BDE-47 is a brominated flame retardant that was widely used in a variety of consumer products and has subsequently been identified as a ubiquitous environmental contaminant. Hydroxy-bromodiphenyl ethers (OH-BDEs) were isolated from rat hepatic microsomes by liquid-liquid extraction. Chromatographic separation was achieved by UPLC on a C18 column with gradient elution using a mobile phase consisting of methanol and water, each containing 0.1% formic acid, at a flow rate of 0.2 mL/min. Detection and quantification were performed using a mass spectrometer in single ion recording mode with negative electrospray ionization. The UPLC/MS method was validated for linearity, limit of quantification (LOQ), accuracy, precision and recovery. The weighted calibration curves (1/X2) were linear over a concentration range of 5 - 250 nM with LOQ values between 5 nM and 50 nM for the individual OH-BDEs. Intra- and inter- day accuracy (%DEV) and precision (%RSD) values ranged from –11.7% to 9.5% and 5.9% to 16.5%, respectively. Recovery values of 70% to 90% were obtained for all OH-BDEs. The validated method allowed us to successfully analyze metabolite formation following incubation of BDE-47 with hepatic microsomes prepared from phenobarbital-treated rats. Results demonstrate that the UPLC/MS method has sufficient sensitivity and reproducibility to fully characterize the in vitro metabolism of BDE-47 and possibly other PBDEs.

Simultaneous Determination and Pharmacokinetics of Tetrandrine,Fangchinoline,and Cyclanoline in Rat Plasma by Ultra-High Performance Liquid Chromatography-Mass Spectrometry after Oral Administration of Stephaniae Tetrandrae Radix Extract

Objective:The objective of the study was to develop a rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometric method for the determination of tetrandrine,fangchinoline,and cyclanoline in rat plasma and to investigate their pharmacokinetics after oral administration of Stephaniae Tetrandrae Radix extracts.Methods:Sample pretreatment involved methanol pretreatment and liquid–liquid extraction of ethyl acetate from plasma with methanol.Tramadol was used as the internal standard.The analysis was performed using an high strength silica T3 column(100 mm×2.1 mm,1.8μm)and a gradient elution method consisting of mobile phase solution A(0.1%formic acid in water)and B(acetonitrile)at a flow rate of 0.4 mL/min.The detection was performed using a triple quadrupole tandem mass spectrometer in the multiple reaction monitoring mode and using an electrospray ionization source in the positive ionization mode.Results:High efficiency was achieved with an analysis time of 4 min/sample.The calibration curve linear in the concentration range of 1250 ng/ml(R^(2)≥0.9900)and the lower limit of quantification is 1 ng/ml.The intraday and interday precision(relative standard deviation)values were lower than 9.4.Accuracy(relative error)was within 10.3%at all three quality control levels.Conclusions:This method was successfully applied in pharmacokinetics of tetrandrine,fangchinoline,and cyclanoline in rats after oral administration of Stephaniae Tetrandrae Radix extracts.The maximum plasma concentration(C_(max))of tetrandrine,fangchinoline,and cyclanoline was 124.71±16.08,84.56±3.28,and 57.61±6.26 ng/mL,respectively.The time to reach C_(max)was 10.39±3.04 for tetrandrine,10.17±3.04 for fangchinoline,and 6.40±3.16 for cyclanoline.The pharmacokinetic results might help further guide the clinical application of Stephaniae Tetrandrae Radix.

Study of Serum Metabonomics and Formula-Pattern Correspondence in Coronary Heart Disease Patients Diagnosed as Phlegm or Blood Stasis Pattern Based on Ultra Performance Liquid Chromatography Mass Spectrometry

Objectives： To study the characteristics of serum metabonomics in coronary heart disease （CHD） patients diagnosed as phlegm or blood stasis pattern and explore effects of formula-pattern correspondence treatment. Methods： A total of 102 stable CHD patients were enrolled and divided into phlegm group （P group, n=52） and blood stasis group （BS group, n=50） according to pattern identification. Gualou Xiebai Banxia Decoction （瓜萎薤白半夏汤, GXBD） and Xuefu Zhuyu Decoction （血府逐瘀汤, XZD） were used as drug interventions. Relevant indicators of metabonomics were observed by ultra performance liquid chromatography mass spectrometry （UPLC-MS） and pattern recognition. Results： Levels of amino acids and phosphatidylethanolamine （PE） in the CHD group were much higher than those in healthy control group, while the levels of unsaturated fatty acids, sphingosine, Lyso, phosphatidylcholine （PC） were significantly lower （P〈0.01）. Most of the differential metabolites between the CHD and the healthy groups were also common metabolites of phlegm and blood stasis. 7（Z）, 10（Z）- hexadecadienoic acid and DPA were decreased in the P group and increased in the BS group. According to the quantity of retraced metabolites, improvement in metabonomics by formula-pattern correspondence was superior to that without correspondence in the BS group. Based on the varieties of metabolites, GXBD could improve the levels of docosapentaenoic acid （DPA）, sphingomyelin （SM） （d34：1）, and L-Lactic acid and XZD could ameliorate the levels of sphingosine and Vit E in the P group, in the BS group, GXBD could improve vitamin E level and XZD could make improvements in the levels of octadecanoic acid, phosphoglycerol, and SM （d34：1）. Conclusions： Phlegm and blood stasis in CHD patients present specific differential metabolites, and share common metabolites. Remarkable differences have been displayed in pathological properties and severity of phlegm and blood stasis. Patients with phlegm are more likely to have lipid metabolism disorders. However, in patients with blood stasis, problems mainly lie in glucose, protein and fat metabolism and the injury of vascular cell membrane is relatively severe. The metabolic disorder is more complicated in blood stasis pattem than that in phlegm pattem. Compared with non-correspondence, improvement of differential metabolites is more comprehensive and targeted in formulapattern correspondence with a better effect.

液液萃取-超高效液相色谱-串联质谱法同时测定尿液中乌头碱和新乌头碱

建立液液萃取-超高效液相色谱-串联质谱法同时测定尿液中乌头碱和新乌头碱的含量。向尿液样品中加入一定量的萃取溶剂,涡旋,离心,取上层有机相,重复萃取两次,合并萃取液,氮吹至干,再复溶于乙腈中。以乙腈和含0.1%甲酸的2 mmol/L甲酸铵溶液作为流动相,梯度洗脱,采用Acquity BEH C_(18)色谱柱分离,电喷雾离子源正离子方式扫描,多反应监测模式监测,以保留时间和特征离子定性,外标法定量。乌头碱和新乌头碱的质量浓度在1.0~100.0μg/L范围内与其色谱峰面积呈良好的线性关系,相关系数均不小于0.998,方法检出限为0.01μg/L。样品加标平均回收率为99.2%~105.4%,测定结果的相对标准偏差为1.7%~4.1%(n=5)。该方法灵敏度高,准确可靠,适用于食物中毒患者尿液中乌头碱和新乌头碱的检测。

超高效液相色谱-串联质谱测定胆石症患者血清胆汁酸谱的意义及价值

目的:探究超高效液相色谱-串联质谱测定胆石症患者血清胆汁酸谱的意义及价值。方法:选取2023年7月至12月收治的83例胆石症患者资料进行回顾性分析,并按1∶1比例选取同期体检健康者83例为对照组。比较两组受试者血清初级胆汁酸谱、次级胆汁酸谱差异,分析胆石症影响因素及胆汁酸谱诊断胆石症的价值效能。结果:研究组受试者牛磺胆酸(TCA)、甘氨鹅脱氧胆酸(GCDCA)、甘氨胆酸(GCA)、甘氨熊脱氧胆酸(GUDCA)、牛磺熊去氧胆酸(TUDCA)、牛磺鹅去氧胆酸(TCDCA)高于对照组,差异有统计学意义(P<0.05)。二元Logistic回归分析显示,TCA、GCDCA、GCA、TUDCA、TCDCA均是胆石症发生的危险因素(P<0.05)。ROC曲线分析显示,TCA、GCDCA、GCA、TUDCA、TCDCA诊断胆石症的AUC分别为0.760、0.755、0.914、0.855、0.880,联合数据诊断胆石症的的AUC分别为0.921,敏感度为91.6%,特异度为97.6%。结论:胆石症患者血清胆汁酸谱存在异常,超高效液相色谱-串联质谱测定的血清胆汁酸谱可作为评估胆石症的有效方式之一,为临床早期预防提供参考。

Determination of Four Chiral Pesticides in Soil by QuEChERS-Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

The enantiomer residues of metalaxyl, napropamide, triticonazole and metconazole were detected in soil by Qu EChERS-ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）. The soil sample was extracted with acetonitrile containing 1% acetic acid and purified using Qu ECh ERS method. Quantitative analysis for the enantiomers of these four chiral pesticides was performed in MS in multi-response monitoring（MRM） mode by external standard method. All enantiomers showed good linearity in the range of 0.5 to 50 μg/L. The average recoveries of enantiomers in soil were 81.74% to 105.79% with relative standard deviations（RSDs） from 3.69% to 7.86%. The method quantitative limit（MQL） was 5.3-30.3 ng/kg. The method can be used for rapid screening and determination of chiral pesticides in soil.

Detecting N-nitrosamines in water treatment plants and distribution systems in China using ultra-performance liquid chromatography-tandem mass spectrometry

N-nitrosodimethylamine （NDMA） and several other N-nitrosamines have been detected as disinfection by-products in drinking waters in many countries around the world. An ultra-performance liquid chromatography- tandem mass spectrometry method with solid phase extraction sample preparation was developed to study the occurrence of N-nitrosamines in several water treatment plants and distribution systems in China. Isotope labeled N-nitrosodi-n-propylamine-dl4 （NDPA-dl4） was selected as the internal standard for quantification. The solid phase extraction procedures including pH, enrichment process and MS/MS parameters including capillary voltage, cone gas flow, cone voltage, collision energy were optimized to give average recoveries of 26% to 112% for nine N- nitrosamine species. The instrument detection limits were estimated to range from 0.5 to 5μg.L-1 for the nine N- nitrosamine species. NDMA and several other N-nitrosa- mines were found at fairly high concentrations in several water treatment plants and distribution systems. NDMA was found in all locations, and the highest concentrations in cities B, G, T, and W were 3.0, 35.7, 21.3, and 19.7 ng. L 1, respectively. A wide range of N-nitrosamines concentrations and species were observed in different locations. Higher concentrations of N-nitrosamines were detected in distribution systems that were further away from the treatment plants, suggesting that the contact time between the residual disinfectant and natural organic matter may play an important role in the formation of these compounds.

Simultaneous Determination of Six Compounds in Rat Plasma by Ultra-Performance Liquid Chromatography with Tandem Mass Spectrometry: Application in the Pharmacokinetic Study of Qing Gan-Shu Yu-Fang

A rapid and high selective ultra-performance liquid chromatography(UPLC)with tandem mass spectrometry method for simultaneous determination of six compounds including albiflorin,paeoniflorin,picroside I,picroside II,saikosaponin A,and saikosaponin D in rat plasma was developed and validated using butyl p-hydroxybenzoate as an internal standard.One-step direct protein precipitation with acetonitrile was used to extract the compounds from the rat plasma samples.Chromatographic separation was achieved using an ACQUITY UPLC BEH C18 column(100 mm×2.1 mm,1.7μm)at a flow rate of 0.4 m L/min,using gradient mode containing 0.1%formic acid in water and acetonitrile were used as the Mobile phase A and B.Electrospray ionization in negative ion mode and multiple reaction monitoring were used to identify and quantify active components.Calibration curves showed good linearity(R^2>0.9908)over a wide concentration range for all compounds.The intra-and interday precision(relative standard deviation)ranged 2.4%–7.0%and 2.6%–8.0%,respectively.The accuracy(relative error)was from-13.0%to 13.2%at all quality control levels.The recovery ranged from 81.1%to 92.5%.The validated method was successfully applied to pharmacokinetic study in rats after oral administration of Qing Gan-Shu Yu-Fang.The results show that one can draw a conclusion that these six active ingredients can be quickly absorbed and play a pharmacodynamic role rapidly in vivo.

基于网络药理学探究双孢菇的肝脏保护作用

为研究双孢菇乙醇提取物(Agaricus bisporus ethanol extract,ABEE)保肝活性的物质基础及其作用机制,采用超高效液相色谱-串联质谱(ultra-high performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)技术对ABEE的成分进行分析鉴定,通过网络药理学结合CCl4致小鼠急性肝损伤动物模型对其活性物质及作用机制进行分析。UPLC-MS/MS分析鉴定化合物75个,其中网络药理学预测与肝损伤活性相关化合物15个,作用靶点11个。动物实验结果显示,ABEE能够显著改善由CCl4导致的小鼠急性肝损伤,与模型组相比,高剂量组(1000 mg/kg)肝功能指标谷草转氨酶、谷丙转氨酶、碱性磷酸酶得到了显著恢复(P<0.001),同时小鼠体内抗氧化能力得到显著提高,与模型组相比,超氧化物歧化酶、谷胱甘肽过氧化物酶活力显著提高(P<0.001),丙二醛含量显著下降(P<0.01)。采用实时荧光定量聚合酶链式反应和Western blot技术对相关基因的mRNA和蛋白表达水平进行检测,结果显示,与模型组相比,高剂量组Bcl-2表达显著上升(P<0.001),MYC、NF-κB1、RELA、MMP9表达显著降低(P<0.01),证实了预测结果。因此,ABEE可能是通过水杨酸、棕榈酸、α-亚麻酸、白杨素调节Bcl-2、MYC、NF-κB1、RELA的表达及其所在的化学致癌-受体激活等信号通路,从而发挥肝脏保护作用。本研究结果表明ABEE可能是通过多成分、多靶点、多通路抑制细胞凋亡、癌变,抑制自由基脂质过氧化来发挥肝脏保护作用。

Rapid Determination of Tetrodotoxin in Human Plasma by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A sensitive analytical method was developed to determine tetrodotoxin（TTX） in human plasma samples using protein precipitation, followed by ultra performance liquid chromatography（UPLC） analysis coupled with tandem mass spectrometry（MS/MS） using 11-deoxytetrodotoxin（11-deoxyTTX） as an internal standard. The plasma samples were prepared using protein precipitation prior to being analyzed by UPLC-MSfMS to identify TTX over a zwitterionic-hydrophilic interaction liquid chromatography column. The retention time values of TTX and 11-deoxyTTX were 4.12 and 3.67 min, respectively. TTX and 11-deoxyTTX were monitored and quantitated on the basis of their ion transitions for their respective precursor ions to their product ions（i.e., m/z 320.0→162. l for TTX and m/z 304.0→176.0 for 11-deoxyTTX） in the multiple reaction-monitoring mode. The lower limit of quantification of this method was determined to be 0.0199 ug/mL. This method showed good linearity for plasma samples that contained TTX concentrations in the range of 0.0199--1.99 ng/mL. The specificity, precision, accuracy, matrix effect, and stability characteristics of this method were also examined. The intra-assay precision and accuracy ranged from 1.89% to 6.00% and from 92.21% to 100.00%, whereas the inter-assay precision and accuracy ranged from 0.64% to 7.75% and from 99.38% to 101.26%, respectively. This new method therefore represents a rapid, accurate, reliable, and highly sensitive method for the qualitative and quantitative analyses of a trace amount of TTX in human plasma samples.