UFLC-MS/MS法分析蜈蚣中3种多肽成分以及在蜈蚣鉴别中的应用

目的建立超高效液相色谱-质谱联用(UFLC-MS/MS)法分析蜈蚣中3种酶解多肽成分TD1(LEEDLERSEERL)、TD2(EEKDKALQNAEGEVAAL)、TD3(MILPTGASSF),比较不同品种蜈蚣中肽类成分的差异,寻找蜈蚣特异性多肽,用于蜈蚣的鉴别。方法3种肽类成分的UFLC-MS/MS法,色谱柱为XSelect HSS T_(3)(4.6 mm×150 mm,3.5μm);流动相为乙腈-0.1%甲酸溶液,梯度洗脱。采用三重四极杆质谱检测器,电喷雾离子化(ESI),正离子模式下多反应监测(MRM)进行信号采集。样品采用正交试验方法,对蛋白提取方法进行优化,最终确定提取方法为蛋白裂解液超声处理60 min。得到的蜈蚣蛋白提取溶液经胃蛋白酶酶解并脱盐后,注入液质联用仪分析。测定了20批蜈蚣及8批其他动物药中3种肽类成分,并对结果进行比较。结果在地龙、僵蚕、水蛭、土鳖虫和全蝎中未检出TD2和TD3,TD1与TD2在少棘巨蜈蚣与哈氏蜈蚣、墨江蜈蚣中存在较大差异,TD3在少棘巨蜈蚣与黑头蜈蚣、多棘蜈蚣中有较大差异。结论该方法可用于区分少棘巨蜈蚣与地龙、僵蚕、水蛭、土鳖虫和全蝎,同时通过比较3种肽段的差异,区分药典品种少棘巨蜈蚣和4种常见非药典品种蜈蚣,为蜈蚣的质量评价和基础研究提供参考。

UFLC-MS/MS检测胡桃楸不同部位有效成分的含量

目的建立超快速高效液相色谱串连三重四级杆质谱法(UFLC-MS/MS)测定胡桃楸不同部位中6种化学成分(原儿茶酸、绿原酸、丁香酸、阿魏酸、鞣花酸、胡桃醌)的方法。方法采用UFLC-MS/MS法及负离子多反应监测(MRM)模式进行含量测定。色谱条件:Aglient C18(4.6 mm×150 mm,5μm)色谱柱;流动相0.2%甲酸水(A)-乙腈(B),梯度洗脱;流速0.6 mL·min^-1,进样量10μL,柱温为25℃。结果胡桃楸中6种化合物在考察的浓度范围内呈良好的线性关系(r>0.9995);回收率和RSD分别在97.72%~98.65%和1.05%~1.93%内。结论建立的UFLC-MS/MS法对胡桃楸不同部位进行定量分析,方法简便、快捷、准确。

UFLC-MS/MS法测定人血浆中阿帕替尼的药物浓度

目的:建立一种灵敏度高、专属性强、便捷、高效的超快速液相色谱-质谱联用方法,用于测定人血浆中阿帕替尼药物浓度。方法:以伊马替尼作为内标物,采用乙腈沉淀血浆中的蛋白;色谱柱:Waters Bridge C_(18)柱(4.6 mm×150 mm,5μm);流动相为A-乙腈和B-1 mmol·L^(-1)甲酸铵,梯度洗脱(0~2.5 min 85%A,2.5~3 min 85%A~50%A,3~4 min 50%A);流速:1 mL·min^(-1);进样量:5μL;柱温:40℃;进样检测时间:4 min;采取ESI离子源,正离子模式下MRM扫描模式,阿帕替尼的离子对为m/z 398.2→212.2,内标的离子对为m/z 494.1→394.1。结果:阿帕替尼在20~1500 ng·mL^(-1)浓度范围内线性关系良好,r=0.999;日内、日间精密度均<15%,方法和提取回收率>90%,进样室、冻融、4℃条件下稳定性的RSD均<10%;患者血浆中阿帕替尼的浓度介于30.90~760.75 ng·mL^(-1)。结论:本实验建立的方法准确度高且操作简单,可在临床用于人血浆中阿帕替尼药物浓度的测定。

UFLC-MS/MS测定大鼠皮下及血液微透析样品中鬼臼毒素浓度

目的建立和验证一个测定大鼠皮肤下及血液微透析样品中鬼臼毒素浓度的超高速液相色谱-质谱联用（UFLC-MS/MS）方法。方法微透析样品中加入依托泊苷为内标,经乙酸乙酯液-液提取后进行UFLC-MS/MS测定。采用Agilent ZORBAX XDB-C18色谱柱（2.1 mm×50 mm,3.5μm）,柱温为室温,以乙腈-10 mmol/L乙酸铵（40∶60,V/V）为流动相,流速0.3 ml/min;质谱采用正离子模式和多反应离子监测方式进行检测。结果用于定量分析的离子对分别为m/z 432.7→397.3（鬼臼毒素）和589.5→229.5（依托泊苷,内标）,鬼臼毒素标准曲线线性范围为2.0~1000 ng/ml,最低定量下限及最低检测限分别为2.0 ng/ml和0.7 ng/ml。日内和日间精密度及准确度均小于15%。结论该方法灵敏度高、专属性强,可用于测定大鼠皮肤下及血液微透析样品中鬼臼毒素含量。

基于UFLC-MS/分子模拟计算的吴茱萸醇提取物中胆碱酯酶抑制剂筛选

采用超高速液相色谱⁃质谱(UFLC⁃MS)研究了吴茱萸醇提取物中入血小分子化合物的体内药代动力学过程.同时对UFLC⁃MS生物样品分析方法进行包括特异性、线性、精密度、准确度、稳定性、基质效应和回收率等考察,结果表明,该方法稳定可靠,且醇提取物中10个生物碱类化合物均被胃肠道快速吸收,并且多数化合物血药浓度在1~2 h左右达到峰值.将吸收入血的10个生物碱类化合物与乙酰胆碱酯酶和丁酰胆碱脂酶进行柔性分子对接及构效关系分析,发现其中活性最高的为去氢吴茱萸碱、吴茱萸碱、吴茱萸次碱和吴茱萸酰胺Ⅰ4个吲哚型生物碱,它们与乙酰胆碱酯酶的对接打分均在-46.02 kJ/mol以下;与丁酰胆碱脂酶对接打分均在-41.84 kJ/mol以下.吴茱萸碱、吴茱萸次碱、去氢吴茱萸碱和吴茱萸酰胺可能是以乙酰胆碱酯酶和丁酰胆碱脂酶为靶点的胆碱酯酶抑制剂前体化合物.

SPE-UFLC-MS/MS法测定制药废水中四环素类抗生素

文章建立了利用固相萃取-超快速液相色谱-串联质谱（SPE-UFLC-MS/MS）测定制药废水中四环素类抗生素（土霉素、四环素和金霉素）残留的方法。水样经（30%硫酸锌＋20%亚铁氰化钾）溶液作为沉淀剂沉淀蛋白质后,上清液采用Oasis HLB固相萃取柱富集和净化,以（0.1%甲酸溶液＋乙腈）为流动相进行梯度洗脱,经Agilent ZORBAX SB C18柱分离后,在串联质谱ES（I＋）模式下进行MRM检测。该方法四环素类抗生素检出限（S/N=3时）0.02μg/L,3种目标物在0.010~1.0 mg/L范围内线性关系良好,线性相关系数在0.998 2~0.999 8之间。在0.20、0.40和0.60μg/L添加水平,各组分的回收率在80.8%~97.2%之间,相对标准偏差在5.31%~9.92%之间。该方法可满足制药废水中四环素类抗生素残留检测的要求。

UFLC-MS/MS法同时测定肺宁颗粒中6种化学成分

目的建立UFLC-MS/MS法测定肺宁颗粒中6种化学成分(绿原酸、原儿茶酸、咖啡酸、对羟基苯甲酸、金丝桃苷及异槲皮苷)的方法。方法采用UFLC-MS/MS法及负离子多反应监测(MRM)模式进行含量测定。色谱条件:Aglient C18色谱柱(4.6 mm×150 mm,5μm);流动相:0.2%甲酸水(A)-乙腈(B),梯度洗脱;进样量:10μl,流速:0.6ml·min-1,柱温:25℃。结果肺宁颗粒中6种化合物在考察的浓度范围内呈良好的线性关系(r>0.9995);回收率和RSD分别在96.61%~103.5%和1.05%~1.93%范围内。结论本研究建立的UFLC-MS/MS法对肺宁颗粒进行定量分析,方法简便、快捷、准确。

Quality assessment of Jinhongtang Granule using UFLC-MS/MS and multivariate statistical analysis

Jinhongtang is a traditional Chinese medicine formula composed of Rheum palmatum L.stem,Sargentodoxa cuneata stem,and Taraxacum mongolicum and is used for the treatment of sepsis.However,quality assessment method for Jinhongtang is not available.In present study,we developed a UFLC-MS/MS method to determine 16 analytes in 20 batches of home-made and commercial Jinhongtang.Multivariate statistical analysis revealed the significant differences in the quality of home-made and commercial Jinhongtang and the difference in the quality of home-made samples was more significant.The integrated strategy based on UFLC-MS/MS and multivariate statistical analysis provided a new basis for the overall quality assessment of Jinhongtang.

Stepped-up development of accelerator mass spectrometry method for the detection of ^(60)Fe with the HI-13 tandem accelerator

The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)Fe.In this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy degrader.For particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the spectrograph.Finally,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS system.These results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)Ni.The sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.

UFLC-MS/MS法同时测定黄芩汤中8个活性成分的含量

目的建立超快速液相色谱-串联质谱法(UFLC-MS/MS)同时测定黄芩汤中黄芩苷、汉黄芩苷、黄芩素、汉黄芩素、芍药苷、芍药内酯苷、甘草苷和甘草酸8个活性成分的含量。方法采用Shim-Pack XRODS色谱柱(75 mm×3.0 mm,2.2μm),流动相为0.1%甲酸水溶液(A)-乙腈(B),梯度洗脱(0~15 min,10%→70%B);流速:0.4 mL·min^(-1);柱温:35℃;进样量:5μL;电喷雾电离源(ESI源)负离子检测,多反应检测(MRM)。结果黄芩汤中8个成分质量浓度分别在浓度范围内与峰面积线性关系良好,平均回收率为98.5%~100.3%。黄芩汤中黄芩苷、汉黄芩苷、黄芩素、汉黄芩素、芍药苷、芍药内酯苷、甘草苷和甘草酸的含量范围分别为0.124~0.135、0.057~0.067、0.259~0.282、0.145~0.158、0.077~0.085、0.0061~0.0064、0.030~0.035、0.0157~0.189 mg·mL^(-1)。结论本方法分析时间短、灵敏度高、稳定性好,可用于黄芩汤的质量控制。

Mass Spectrometry-based Deep Coverage Proteome:Evaluation of Cellular Protein Extraction Methods

The current study comprehensively evaluates four different protein extraction methods based on urea,sodium dodecyl sulfate(SDS),anionic surfactants(BT),and total RNA extractor(Trizol),aiming to optimize the sample preparation workflow for mass spectrometry-based proteomics.Using HeLa cells as an example,we found that the method employing the mass spectrometry-compatible surfactant BT reagent significantly reduces the total time consumed for protein extraction and minimizes protein losses during the sample preparation process.Further integrating the four protein extraction methods,we identified over 7000 proteins from HeLa cells without relying on pre-fractionation techniques,and 2990 of them were quantified using label-free quantification.It is worth noting that the BT and SDS methods demonstrate higher efficiency in extracting membrane proteins,while the Urea and Trizol methods are more effective in extracting proteins from nuclear and cytoplasmic fractions.In summary,this study provides a novel solution for deep proteome coverage,particularly in the context of cellular protein extraction,by integrating mass spectrometry-compatible surfactants with traditional extraction methods to effectively enhance protein identification numbers.

Bacterial Protein Profiling——Comparison of Three Mass Spectrometry Methodologies

Profiling the protein composition of bacteria is essential for understanding their biology,physiology and interaction with environment.Mass spectrometry has become a pivotal tool for protein analysis,facilitating the examination of expression levels,molecular masses and structural modifications.In this study,we compared the performance of three widely-used mass spectrometry methods,i.e.,matrix-assisted laser desorption/ionization(MALDI)protein fingerprinting,top-down proteomics and bottom-up proteomics,in the profiling of bacterial protein composition.It was revealed that bottom-up proteomics provided the highest protein coverage and exhibited the greatest protein profile overlap between bacterial species.In contrast,MALDI protein fingerprinting demonstrated superior detection reproducibility and effectiveness in distinguishing between bacterial species.Although top-down proteomics identified fewer proteins than bottom-up approach,it complemented MALDI fingerprinting in the discovery of bacterial protein markers,both favoring abundant,stable,and hydrophilic bacterial ribosomal proteins.This study represents the most systematic and comprehensive comparison of mass spectrometry-based protein profiling methodologies to date.It provides valuable guidelines for the selection of appropriate profiling strategies for specific analytical purposes.This will facilitate studies across various fields,including infection diagnosis,antimicrobial resistance detection and pharmaceutical target discovery.

Ultra-soft Desorption Assisted Mass Spectrometry using Picosecond Infrared Laser for the Detection of lons in the Liquid Surface

To identify the species in liquid surface using mass spectrometry,we must eliminate or reduce interferences during the vaporization or desorption of the species from the liquid surface.It is much more challenging to isolate the ionic,larger species from the liquid surface,because of the frangible structures and the higher solvation energies of those species.Here we demonstrate a new mass spectrometry in which the ionic species at the liquid surface can be desorbed with ultrasoft infrared picosecond laser pulses while the liquid surface is not breached.This laser desorption assisted mass spectrometry is not only a powerful tool to detect the fragile species but also promising to investigate vibrational energy transfer dynamics in the liquid surface.

Determination of 13 preservatives in cosmetics by high performance liquid chromatography and verification by mass spectrometry

A method using high performance liquid chromatography(HPLC)was developed for the s imultaneous determination of 13 preservatives(levulinic acid,p-hydroxyacetophenone,raspberry ketone,p-anisic acid,caprylhydroxamic acid,hydroxyethoxyphenyl butanone,methylisothiazolinone,phenoxyethanol,b e n z oic acid,methylparaben,chlorphenesin,dehydroacetic acid,and 5-bromo-5-nitro-1,3-dioxane)in cosmetics.Different types of samples were ultrasonically extracted by methanol,then the separation of 13 preservatives was carried out on a column of Agilent ZORBAX Eclipse XDB-C18(250 mm×4.6 mm,5μm)by gradient elution at a flow rate of 1.0 mL/min,using 0.1%phosphoric acid solution and acetonitrile as mobile phases.The column temperature was 30℃,and the detection was completed by a diode array detector with the wavelengths at 275,230 and 210 nm.Suspected positive samples were further confirmed by liquid chromatography-tandem mass spectrometry or gas chromatography-mass spectrometry.The linear regression analysis data shows good linearity for 13 preservatives in the respective mass concentration range,with their correlation coefficients(r)greater than 0.9998.The limits of detection(LODs)and limits of quantitation(LOQs)of the method are in the ranges of 0.4-100.0 mg/kg and 1.2-250.0 mg/kg,respectively.At three spiked levels,the average recoveries for 13 target compounds in three kinds of matrix samples are within 84.0%-115.4%,and the relative standard deviations(RSD)are within 0.5%-4.8%(n=6).This method is convenient,efficient,and precise,which can be used for qualitative and quantitative analysis of common preservatives in daily cosmetics.

Improved isochronous mass spectrometry with tune measurement

In conventional isochronous mass spectrometry(IMS)performed on a storage ring,the precision of mass measurements for short-lived nuclei depends on the accurate determination of the revolution times(T)of stored ions.However,the resolution of T inevitably deteriorates due to the magnetic rigidity spread of the ions,limiting the mass-resolving power.In this study,we used the betatron tunes Q(the number of betatron oscillations per revolution)of the ions and established a correlation between T and Q.From this correlation,T was transformed to correspond to a fixed Q with higher resolution.Using these transformed T values,the masses of ^(63)Ge,^(65)As,^(67)Se,and ^(71)Kr agreed well with the mass values measured using the newly developed IMS(Bρ-IMS).We also studied the systematics of Coulomb displacement energies(CDEs)and found that anomalous staggering in CDEs was eliminated using new mass values.This method of T transformation is highly effective for conventional IMS equipped with a single time-of-flight detector.

Mapping conformational changes on bispecific antigen-binding biotherapeutic by covalent labeling and mass spectrometry

Biotherapeutic's higher order structure(HOS)is a critical determinant of its functional properties and conformational relevance.Here,we evaluated two covalent labeling methods:diethylpyrocarbonate(DEPC)-labeling and fast photooxidation of proteins(FPOP),in conjunction with mass spectrometry(MS),to investigate structural modifications for the new class of immuno-oncological therapy known as bispecific antigen-binding biotherapeutics(BABB).The evaluated techniques unveiled subtle structural changes occurring at the amino acid residue level within the antigen-binding domain under both native and thermal stress conditions,which cannot be detected by conventional biophysical techniques,e.g.,near-ultraviolet circular dichroism(NUV-CD).The determined variations in labeling uptake under native and stress conditions,corroborated by binding assays,shed light on the binding effect,and highlighted the potential of covalent-labeling methods to effectively monitor conformational changes that ultimately influence the product quality.Our study provides a foundation for implementing the developed techniques in elucidating the inherent structural characteristics of novel therapeutics and their conformational stability.

Determination of 14 Organophosphorus Pesticide Residues in Mutton by Gel Permeation Chromatography-Gas Chromatography-Mass Spectrometry(GPC-GC-MS)

[Objectives]This study was conducted to purify mutton samples by gel permeation chromatography(GPC).[Methods]Fourteen organophosphorus pesticide residues in samples were qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry(GC-MS)in selective ion scanning mode(SIM).[Results]The organophosphorus pesticide standard solutions showed good linearity in the mass concentration range of 0.1-10.0μg/ml with correlation coefficients(r)not lower than 0.999,and the detection limits(S=3 N)ranged from 0.01 to 0.05 mg/kg.The average recovery values were in the range of 80.2%-99.7%,with relative standard deviations(RSDs,n=3)in the range of 1.8%-6.3%,at the addition levels of 0.5,1.0 and 2.0 mg/kg.[Conclusions]The method is simple,sensitive and accurate,and can be used for the determination of organophosphorus pesticide residues in mutton.

UFLC-MS/MS法同时测定龙胆中7个活性成分的含量

建立可同时测定龙胆中7个活性成分(马钱苷酸、獐牙菜苦苷、6'-O-β-D-葡萄糖基龙胆苦苷、龙胆苦苷、獐牙菜苷、异荭草苷和异牡荆素)含量的超快速液相色谱-串联质谱方法。流动相采用0.1%甲酸水溶液(A)-乙腈(B),色谱柱Shim-Pack XR-ODS(75 mm×3.0 mm,2.2μm),梯度洗脱;采用三重四极杆串联质谱仪,电喷雾电离源,正离子模式监测。上述7个成分线性浓度范围分别为2.5~100μg·mL^(-1)(r=0.9996)、1~40μg·mL^(-1)(r=0.9995)、1~40μg·mL^(-1)(r=0.9995)、5~200μg·mL^(-1)(r=0.9996)、0.1~4μg·mL^(-1)(r=0.9995)、0.05~2μg·mL^(-1)(r=0.9998)和0.01~0.4μg·mL^(-1)(r=0.9995)。6批龙胆样品中上述7个成分的含量分别为0.894%~1.072%、0.260%~0.285%、0.223%~0.268%、3.88%~4.05%、0.00726%~0.00898%、0.000840%~0.00195%和0.000779%~0.00104%。该方法灵敏、稳定,可用于龙胆药材的质量控制。

Research on the Upper Limit of Accuracy for Predicting Theoretical Tandem Mass Spectrometry

In recent years, numerous theoretical tandem mass spectrometry prediction methods have been proposed, yet a systematic study and evaluation of their theoretical accuracy limits have not been conducted. If the accuracy of current methods approaches this limit, further exploration of new prediction techniques may become redundant. Conversely, a need for more precise prediction methods or models may be indicated. In this study, we have experimentally analyzed the limits of accuracy at different numbers of ions and parameters using repeated spectral pairs and integrating various similarity metrics. Results show significant achievements in accuracy for backbone ion methods with room for improvement. In contrast, full-spectrum prediction methods exhibit greater potential relative to the theoretical accuracy limit. Additionally, findings highlight the significant impact of normalized collision energy and instrument type on prediction accuracy, underscoring the importance of considering these factors in future theoretical tandem mass spectrometry predictions.

Chemical profiling of bioactive compounds in the methanolic extract of wild leaf and callus of Vitex negundo using gas chromatographymass spectrometry

BACKGROUND The investigation of plant-based therapeutic agents in medicinal plants has revealed their presence in the extracts and provides the vision to formulate novel techniques for drug therapy.Vitex negundo(V.negundo),a perennial herb belonging to the Varbanaceae family,is extensively used in conventional medication.AIM To determine the existence of therapeutic components in leaf and callus extracts from wild V.negundo plants using gas chromatography-mass spectrometry(GCMS).METHODS In this study,we conducted GC-MS on wild plant leaf extracts and correlated the presence of constituents with those in callus extracts.Various growth regulators such as 6-benzylaminopurine(BAP),2,4-dichlorophenoxyacetic acid(2,4-D),α-naphthylacetic acid(NAA),and di-phenylurea(DPU)were added to plant leaves and in-vitro callus and grown on MS medium.RESULTS The results clearly indicated that the addition of BAP(2.0 mg/L),2,4-D(0.2 mg/mL),DPU(2.0 mg/L)and 2,4-D(0.2 mg/mL)in MS medium resulted in rapid callus development.The plant profile of Vitex extracts by GC-MS analysis showed that 24,10,and 14 bioactive constituents were detected in the methanolic extract of leaf,green callus and the methanolic extract of white loose callus,respectively.CONCLUSION Octadecadienoic acid,hexadecanoic acid and methyl ester were the major constituents in the leaf and callus methanolic extract.Octadecadienoic acid was the most common constituent in all samples.The maximum concentration of octadecadienoic acid in leaves,green callus and white loose callus was 21.93%,47.79%and 40.38%,respectively.These findings demonstrate that the concentration of octadecadienoic acid doubles in-vitro compared to in-vivo.In addition to octadecadienoic acid;butyric acid,benzene,1-methoxy-4-(1-propenyl),dospan,tridecanedialdehyde,methylcyclohexenylbutanol,chlorpyrifos,n-secondary terpene diester,anflunine and other important active compounds were also detected.All these components were only available in callus formed in-vitro.This study showed that the callus contained additional botanical characteristics compared with wild plants.Due to the presence of numerous bioactive compounds,the medical use of Vitex for various diseases has been accepted and the plant is considered an important source of therapeutics for research and development.