靶细胞提取和高效液相飞行时间质谱联用分析预测丹参中的活性成分

建立靶细胞提取和与高效液相飞行时间质谱联用(HPLC-ESI/TOFMS)分析相结合进行丹参活性成分研究的方法,对丹参中可能的活性成分进行了推测。将靶细胞和丹参样品一起孵育培养,根据活性成分可以与靶细胞膜有特异性的结合或者进入靶细胞内的原理,用HPLC-MS方法对培养后细胞破碎液中的成分进行分析。从加药Raw264.7细胞和Ecv304细胞破碎液中检测到丹参素、原儿茶醛、咖啡酸、丹酚酸D、紫草酸、迷迭香酸及丹酚酸B7种丹参中成分,在加药的HL7702细胞破碎液中检测出丹参素、原儿茶醛、咖啡酸及丹酚酸B4种丹参中的水溶性成分。结果显示:细胞破碎液中检测的成分为丹参在靶细胞中有吸收的成分,本方法可用于预测中药中的活性成分。     

丹参脂溶性成分结构优化研究进展

丹参作为一种传统中药在临床上广泛应用于心脑血管疾病的治疗,对其有效成分及衍生物的研究一直是国内外的研究热点.丹参的有效成分主要分为脂溶性成分和水溶性成分,其脂溶性成分具有多种药理活性,但因其水溶性不足、生物利用度低的缺点限制了临床应用.为了能够推进丹参脂溶性成分的临床应用,研究人员以丹参脂溶性成分为先导化合物进行结构优化,以期能够提高其类药性.综述了近年来丹参主要脂溶性成分的结构优化及相关药理活性的研究进展,总结了主要脂溶性成分的成药性结构优化策略以及该类衍生物的合成方法,阐述了不同位置结构优化对药理活性的影响,旨在为丹参脂溶性成分创新药物的研发提供新的研究思路.     

丹参酮ⅡA和丹参酮Ⅰ的电子轰击与电喷雾电离质谱分析

采用电喷雾电离质谱(ESI-MS)和电子轰击质谱(EI-MS)两种质谱技术分别对传统中药丹参的主要脂溶性活性成分丹参酮ⅡA和丹参酮Ⅰ的化学结构和裂解途径进行系统研究。采用EI-MS从丹参酮ⅡA获得m/z 294[M] 、279、261、233、207等特征质谱峰,从丹参酮Ⅰ获得m/z 276[M] 、248、233、219、205等特征质谱峰;采用ESI-MS从丹参酮ⅡA获得m/z 295[M H] 、280、278、262、249等特征质谱峰,从丹参酮Ⅰ获得m/z 277[M H] 、259、249、231、221、193等特征质谱峰,并用Mass Frontier 3.0软件辅助解析了其中的主要特征碎片离子以及可能的裂解途径;比较了丹参酮ⅡA和丹参酮Ⅰ的电喷雾电离质谱和电子轰击质谱裂解规律,本研究为研究丹参二萜醌类主要特征活性成分的生物转化与结构修饰提供了依据。     

基于化学指纹图谱和抗血小板聚集效价的丹参质量评价

通过化学分析和生物活性评价考察丹参药材的品质差异,探讨丹参抗血小板聚集生物活性的主要贡献成分.采用高效液相色谱(HPLC)技术建立丹参药材HPLC指纹图谱,以抗血小板聚集相对效价作为指标,评价不同产地不同批次丹参药材的品质差异,构建基于化学表征及生物效价测定的评价模式.结果表明,不同批次丹参药材的HPLC指纹图谱相似度很高(相似度0.930~0.998),而其抗血小板聚集相对效价相差10倍,提示化学指纹图谱难以反映丹参的活性和质量差异.通过化学指纹图谱与抗血小板聚集生物效价进行谱效相关分析,筛选出与生物活性相关系数大于0.5的6个色谱峰:二氢丹参酮Ⅰ、隐丹参酮、丹参酮Ⅰ、丹参酮ⅡA及2个未知化合物.对上述4种已知化合物单体进行活性验证发现,隐丹参酮的抗血小板聚集活性最强,而其它3种丹参酮类化合物几乎没有体外抗血小板聚集活性.进一步比较丹参中高含量成分丹酚酸B与低含量成分隐丹参酮的活性贡献,结果表明,两者的活性贡献基本相当,说明隐丹参酮是丹参中低含量高活性成分,对评价丹参质量具有重要贡献度.     

山东不同产地丹参的HPLC指纹图谱-化学模式识别研究

建立RPHPLC指纹图谱-化学模式识别评价丹参质量的方法.利用RPHPLC法测定不同产地丹参药材的指纹图谱及丹参酮ⅡAt和丹参酮的含量,采用主成分分析、系统聚类分析和逐步判别分析对指纹图谱信息进行化学模式识别研究.在主成分分析的基础上,以前4个主成分为聚类分析的指标进行系统聚类分析,取阈值为8时,所有样品可被分为4类;并建立了相应的判别函数,回判准确率100%;以此为依据,初步建立了丹参化学模式识别的评价方法.     

UPLC-Q-TOF/MS分析不同比例丹参配伍藜芦毒性生物碱变化规律

利用超高效液相色谱-飞行时间质谱联用技术研究不同配伍比例的丹参藜芦的化学指纹图谱, 并分析毒性生物碱在不同比例配伍混煎前后溶出量的变化. 同时利用小鼠的急性毒性实验来考察配伍后的毒性变化规律. 结果显示在正离子模式下, 各配伍组(A～H)样本之间的差异能得到明显区分, 并结合Loadings图谱和数据库确定了配伍化学指纹图谱中的17种藜芦生物碱毒性成分, 当固定藜芦用量为LD₅₀且藜芦比例大于丹参时, 藜芦定、伪介芬胺等生物碱溶出高于或与藜芦单煎液相当, 但随着丹参比例增加, 上述生物碱溶出呈逐渐下降趋势, 当丹参比例大于藜芦时, 生物碱溶出低于藜芦单煎液. 不同比例丹参藜芦配伍急性毒性实验毒性变化规律与上述生物碱含量的变化趋势吻合, 表明上述毒性生物碱可能是藜芦与丹参特定比例配伍后毒性增强主要化学标志物.     

复方丹参片的高效液相色谱/质谱特征图谱研究

研究了复方丹参片乙醇提取物电喷雾离子阱质谱(ESI-MS)和(HPLC-MS)特征图谱,并对特征图谱中各主要峰进行了初步定性分析,为复方丹参片的快速指纹鉴别提供了新方法。     

微波辅助萃取与超声波萃取丹参中丹酚酸B的比较研究

本文对微波辅助萃取和超声波萃取丹参中丹酚酸B进行了比较研究,并用高效液相色谱法(HPLC)测定了丹参中丹酚酸B.考察了微波辅助萃取和超声波萃取参数的影响,在各自最佳萃取条件下进行了丹参中的丹酚酸B提取率的比对,结果表明:微波辅助萃取6 min的提取率高于超声波萃取30 min的提取率.微波辅助萃取法与超声波萃取法相比具有省时、高效和溶剂用量少的特点.利用指纹图谱比较了两种萃取方式提取的化学成分的差异,结果显示两种萃取方法提取的主要成分组成基本相同,其共有成分比例相近.     

基于多指标含量测定结合化学计量学的不同产地丹参品质差异分析

为对比分析产地对丹参中酚酸类和丹参酮类成分的影响,采用超高效液相色谱（UPLC）及超高效液相色谱－三重四极杆质谱联用技术（UPLC－QQQ－MS）同时测定来自山东、河南、陕西、四川、安徽共408份丹参中23种化学成分的含量,并对数据进行多元统计分析。研究发现17种酚酸类及6种丹参酮类成分在不同产地丹参中均存在显著差异。山东的丹参样品中丹参酮类成分含量最高,四川的样品中丹酚酸B含量最高,安徽丹参的紫草酸、丹酚酸Y、丹酚酸A、丹酚酸D和丹酚酸E等的含量最高。多种模式识别方法均可用于不同产地丹参的判别分析,线性判别分析（LDA）为产地溯源的最佳模型。正交偏最小二乘法判别分析（OPLS－DA）表明不同产地丹参的化学成分差异较大,不同来源丹参的质量差异标志物不仅限于丹酚酸B、丹参酮Ⅰ、隐丹参酮、丹参酮ⅡA,其他丹酚酸类及丹参酮类也是重要的质量标志物。该研究对全国不同主产区的栽培丹参进行多指标含量测定及建模分析,所建立的定量方法专属性强、准确高效,可为不同产地丹参的质量控制及产地判别提供参考。     

基于定量指纹图谱技术的中药质量控制

定量指纹图谱技术是中药指纹图谱技术与多指标成分定量分析相结合的中药质量控制模式。定量指纹图谱技术的发展包括定量组分的制备、过程控制的指纹图谱技术和产品含量测定3个主要部分。本文以丹参为例,通过水提、醇沉、过膜、大孔树脂分离和工业色谱分离5个工艺流程制备了丹参定量组分,对各个工艺步骤以指纹图谱技术考察其稳定性和重复性。对丹参定量组分中的原儿茶醛、迷迭香酸、丹酚酸B 3个成分进行含量测定。3个成分的含量总和大于50%。定量组分的制备以现有的活性成分为目标,经过去粗存精的工艺过程,其质量标准得到了有效的提高。     

天麻中对羟基苯类化合物的高效液相色谱-质谱研究

天麻中对羟基苯类化合物的(EsI(-))一级质谱图中除分子离子峰[M-1]外，还可见明显的[M-1 20] m[2m-1]峰，由此规律可方便确证未知同类样品的分子离子峰。由二级质谱(ESI/MS/MS)的特征碎片离子93、105和107等，结合紫外光谱及核磁结果确定了3个不纯样品中主要成分的结构，同时初步确定了两个同类杂质的结构。     

Electrospray ionization mass spectrometry fingerprinting of beer

After just simple degassing, dilution, pH adjustment and direct flow injection, characteristic fingerprint spectra of beer samples have been obtained by fast (few seconds) electrospray ionization mass spectrometry (ESI-MS) analysis in both the negative and positive ion modes. A total of 29 samples belonging to the two main beer types (lagers and ales) and several beer subtypes from USA, Europe and Brazil could be clearly divided into three groups both by simple visual inspection of their ESI(+)-MS and ESI(-)-MS fingerprints as well as by chemometric treatment of the MS data. Diagnostic ions with contrasting relative abundances in both the positive and negative ion modes allow classification of beers into three major types: P = pale (light) colored (pilsener, pale ale), D = dark colored (bock, stout, porter, mild ale) and M = malt beer. For M beers, samples of a dark and artificially sweetened caramel beer produced in Brazil and known as Malzbiers were used. ESI-MS/MS on these diagnostic beer cations and anions, most of which are characterized as arising from ionization of simple sugars, oligosaccharides, and iso-alpha-acids, yield characteristic tandem mass spectra adding a second and optional MS dimension for improved selectivity for beer characterization by fingerprinting. Direct ESI-MS or ESI-MS/MS analysis can therefore provide fast and reliable fingerprinting characterization of beers, distinguishing between types with different chemical compositions. Other unusual polar components, impurities or additives, as well as fermentation defects or degradation products, could eventually be detected, making the technique promising for beer quality control.     

Synthesis and Electrospray Ionization Mass Spectra of N-（1,3, 2-Dioxaphosphorinan-2-ylmethyl）thiophosphoramidates

N-（1,3,2-Dioxaphosphorinan-2-ylmethyl）thiophosphoramidates were synthesized and determined by NMR spectra and positive ion electrospray ionization mass spectrometry （ESI-MS） in conjunction with tandem mass spectrometry （MS/MS）. The fragmentation pathways were investigated. The results show that these characteristic ions in ESI mass spectra are useful in the structural determination of N-（1,3,2-dioxaphosphorinan-2-ylmethyl）- thiophosphoramidates.     

A study of the electrospray ionisation and ion trap fragmentation of hemiterpenoid and dimeric coumarin derivatives

The electrospray ionisation (ESI) of selected hemiterpenoid and dimeric coumarin derivatives and their subsequent fragmentation using an ion trap mass spectrometer are reported and discussed. Sequential product ion fragmentation experiments (MS(n)) were performed in order to elucidate the degradation pathways for these compounds. The results illustrate that the observed characteristic fragmentation patterns are of considerable utility in the application of ESI mass spectrometry to the characterisation of this class of compounds.     

Instrument dependence of electrospray ionization and tandem mass spectrometric fragmentation of the gingerols

The gingerols, including [6]-, [8]-, and [10]-gingerols, a series of chemical homologs differentiated by the length of their unbranched alkyl chains, have been identified as major active components in fresh ginger rhizome. The purpose of this study was to investigate the utility of ion trap liquid chromatography/tandem mass spectrometry (LC/MS/MS) as an online tool to identify and quantify these compounds in raw or processed ginger rhizome samples. Negative mode electrospray ionization (ESI) was used in MS, MS/MS and MS(n) experiments in quadrupole ion trap instruments from two different manufacturers and in high-resolution and accurate mass MS and MS/MS experiments in a Fourier transform ion cyclotron resonance mass spectrometer to elucidate the ionization and fragmentation mechanisms of these compounds in these instruments. Positive mode ESI, which generated many more fragment ions in full scan MS even under gentle ionization conditions, was also used in LC/MS and MS/MS experiments and in direct infusion MS and MS/MS experiments. Consistent and predictable ionization and fragmentation behaviors were observed for all gingerols when analyzed in the same instrument. Instruments from different manufacturers, however, had different ionization mechanisms. The major difference between instruments was their ability to form covalent dimer adducts of the gingerols. Subsequent fragmentation patterns of the precursor ions were essentially identical. These results clearly demonstrate that LC/MS instruments produce data that cannot necessarily be replicated in other laboratories, especially if those laboratories do not have the same instrument model from the same manufacturer. This presents major problems for metabolite target analysis, metabolic profiling and metabolomics investigations, which would benefit from LC/MS mass spectrum libraries as they do from GC/MS mass spectrum libraries, because such libraries may not be valid across platforms.     

Stereochemical differentiation of C‐7 hydroxyltaxane isomers by electrospray ionization mass spectrometry

In this study, different electrospray ionization mass spectrometric (ESI‐MS) methods were utilized to analyze several pairs of taxane stereoisomers including paclitaxel and 7‐epi‐paclitaxel. Both ESI‐MS and tandem mass spectrometry (MS/MS) techniques provided stereochemically dependent mass spectra in negative‐ion mode, and all studied stereoisomers could be easily distinguished based on their characteristic ions or distinct fragmentation patterns. MS/MS experiments for several taxane analogues at various collision energies were performed to elucidate potential dissociation pathways. The gas‐phase deprotonation potentials were also calculated to estimate the most thermodynamically favorable deprotonation site using DFT B3LYP/6‐31G(d). The results of the theoretical studies agreed well with the fragmentation patterns of paclitaxel and 7‐epi‐paclitaxel observed from MS/MS experiments. In addition, it was found that liquid chromatography (LC)/ESI‐MS was a useful and sensitive technique for assignment of C‐7 taxane stereoisomers from realistic samples. Copyright © 2009 John Wiley & Sons, Ltd.     

Investigation of structure, dynamics and function of metalloproteins with electrospray ionization mass spectrometry

Electrospray ionization mass spectrometry (ESI MS) has emerged recently as a powerful tool for analyzing many structural and behavioral aspects of metalloproteins in great detail. In this review we discuss recent developments in the field, placing particular emphasis on the unique features of ESI MS that lend themselves to metalloprotein characterization at a variety of levels. Direct mass measurement enables the determination of protein-metal ion binding stoichiometry in solution and metalloprotein higher order structure in the case of multi-subunit proteins. MS techniques have been developed for determining the locations of metal-binding centers, metal oxidation states and reaction intermediates of metal-containing enzymes. Other ESI MS techniques are also discussed, such as protein ion charge state distributions and hydrogen/deuterium exchange studies, which can be used to measure metal binding affinities and to shed light on vital dynamic aspects of the functional properties of metalloproteins endowed by metal binding.     

新型包覆Pd纳米粒子液相色谱-串联质谱法用于鉴定沙特阿拉伯原油中的含氧化合物(英文)

Saudi Arabian crude oil is a super complex mixture and,up to now,there has been little research into its heteroatom-containing compounds.First,oxygenated compounds(OCs)were isolated from Saudi Arabian oil using a Pd nanoparticle exchange complex,which formed between the nano-Pds and the oxygenated ligands.Normally,polycyclic aromatic sulphur heterocycles(S-PAHs)are separated from petroleum oil via the same method.The obtained results reveal that all the OC formulations with S-PAHs can be separated from the pre-isolated aromatic fraction of crude oil via this approach.S-PAHs are mixtures of benzothiophene and dibenzothiophene congeners.The isolated OCs are composed mainly of hydroxyl compounds.The liquid chromatography(LC)/electrospray ionization(ESI)in positive ion mode ESI(+)/tandem mass spectrometry(MS/MS)technique was used to assign the molecular weight distribution and identify the isolated OCs.The LC/ESI(+)-MS/MS technique differentiates S-PAHs and OCs using protonated ions.Thus,LC/ESI(+)-MS/MS can be used to assign molecular weight distributions for both the groups as a single mixture.MS/MS in precursor ion mode was used for the immediate identification of the target S or O analytes.     

Applications of electrospray ionization mass spectrometry to neutral organic molecules including fullerenes

The use of electrospray ionization mass spectrometry (ESI/MS) for the detection of neutral organic molecules becomes possible by their derivation with specific ESI/MS tagging reagents that have either proton or metal ion binding sites. We used the neutral crown ether group in several reagents to attach a metal binding site to substrate molecules. Application of this method to steroids, amino acids, vitamin D, fatty acids, and fullerenes is described. Besides characterization, tagged molecules can be used for studying organic reactions by ESI/MS. This work demonstrates that ESI/MS provides a unique window on fullerene solution chemistry. ESI/MS is not only an excellent tool for the analysis of biopolymers but is also useful for studying the organic chemistry of small neutral molecules.     

甾体磷酰胺类缀合物在电喷雾质谱中的裂解特征

Novel steroidal phosphoramidate conjugates of 3'-azido-2',3'-dideoxythymidine(AZT)and amino acid esterswere synthesized and determined by positive and negative ion electrospray ionization mass spectrometry.The MSfragmentation behaviors of the steroidal phosphoramidate conjugates have been investigated in conjunction withtandem mass spectrometry of ESI-MS/MS.There were three characteristic fragment ions in the positive ion ESImass spectra,which were the Na adduct ions with loss of steroidal moiety,amino acid ester moiety from pseudomolecular ion(M Na)~ ,and the phosphoamino acid methyl ester Na adduct ion by α-cleavage of the phosphora-midate respectively.The main fragment ions in negative ion ESI mass spectra were the ion(M-HN_3)~-,the ion(M-AZT-H)~-,and the ion(M-steroidal moiety-H)~- besides the pseudo molecular ion(M-H)~-.Thefragmentation patterns did not depend on the attached amino acid ester moiety.