银杏内酯提取物中微量成分的LC-DAD-ESI-MS分析及结构鉴定

银杏叶ginkgo biloba .L中含有多种二萜内酯和倍半萜内酯.Furukawa.S于1932年首次分离得到银杏内酯混合物;直到1967年,才由Koji Nakanishi和Okabe.K等人鉴定出其中各个成分的结构,并分别命名为Ginkgolide A、B、C、M(简称GA、GB、GC、GM)[1];Weinges K等分别于1969年和1987年分离并鉴定出白果内酯(Bilobalide,BD)[2]和Ginkgolide J[3](GJ).银杏内酯具有抗血小板活化因子(PAF)的作用[4],引起了世界医疗行业的广泛关注.对银杏内酯的HPLC分析常见的检测方法主要有UV、RI和近年出现的ELSD[5],但这些检测方法都有各自的缺陷,UV需在末端检测,易受干扰;RI不适合作梯度洗脱;ELSD灵敏度相对较低.随着对该类化合物的深入研究,发现银杏内酯提取物中尚有一些微量成分,用这些检测方法不足以获得较好的信号响应,本实验以质谱作为检测器,获得了较高的检测灵敏度,结合UV和MS提供的光谱信息,有利于分析鉴别微量成分.     

沉积岩中微量磷酸盐的物相分析

磷酸铁、磷酸铝不溶于醋酸,难溶于低浓度的硝酸。磷酸钙、磷酸镁、磷酸锰则溶于醋酸和低浓     

普通有机化学实验中未知物的鉴定

有机化学实验是化学系教学计划中的一门重要基础实验课程,因此如何进一步提高教学质量,在加强对学生的基本操作和技能训练的同时,加强培养学生的独立工作能力,一直是大家比较关心的问题。我们根据宜昌召开的部属综合性大学化学系课程结构研究会上所提出的精神,“教给学生实验的设计思想,培养同学的判断、想象、思维能力,运用所学知识解决实际问题的能力与文字表达能力,培养学生科学的研究方法及实事求是、一丝不苟的科学态度和作风”。同时考虑到有机化合物结构的鉴定是有机化学的重要组成内容。过去这部分内容是安排在四     

人血浆中YG-3LC-MS-MS 定量方法的建立

YG-3是1种正在开发的核苷类抗乙肝病毒新药,它可抑制乙肝病毒的复制过程.由于YC-3是目前体外抗病毒活性最强的核苷类似物,其临床试验的用药剂量非常小,仅为μg级.因此为满足其药代动力学研究的要求,本实验室建立了1种具有非常高灵敏度的LC-MS-MS方法,可定量测定人血浆中pg级YC-3的浓度,并通过了方法学考核,为YG-3药代动力学研究提供了有利的条件.     

罗汉果提取物中有效成分的结构分析

罗汉果是广西特产罗汉果属植物[Siraitia grosvenorii（Swingle）]的果实。本文对已分离纯化的罗汉果有效成分，采用UV、FTIR和ESI-MS-MS对其进行结构分析。确定组分A1是罗汉果醇-3-o-[β-D-葡萄吡喃糖基（1-6）-β-D-葡萄吡喃糖苷]-24-o-[β-D-葡萄吡喃糖基（1-2）-β-D-葡萄吡喃糖苷]，组分A2是罗汉果醇-3-o-[β-D-葡萄吡喃糖基（1-6）-β-D-葡萄吡喃糖苷]-24-o-{[β-D-葡萄吡喃糖基（1—2）]-[β-D-葡萄吡喃糖基（1—6）]-β-D-葡萄吡喃糖苷}，组分A3是罗汉果醇-3-o-[β-D-葡萄吡喃糖基（1—6）-β-D-葡萄吡喃糖基（1—2）-β-D-葡萄吡喃糖苷]-24-o-{[β-E-葡萄吡喃糖基（1—2）]-β-D-葡萄吡喃糖基（1—6）]-β-D-葡萄吡喃糖苷}。     

生物样品中他莫昔芬LC-MS-MS 定量方法的建立

他莫昔芬(三苯氧胺,Tamoxifen,TAM)为英国研制的非甾体类抗雌激素药物.TAM(N)与雌激素(E)一样,可自由通过癌组织的细胞膜,癌细胞的胞浆中存在雌激素受体(Rc),N与E相互竞争与Rc结合,形成复合物NRc,NRc到细胞核内,形成核(n)受体复合物(NRn),NRn与ERn(同E结合的核受体复合物)不同,NRn不能促进DNA和m-RNA的合成,因而抑制了癌细胞的增殖.TAM用于雌激素受体阳性的绝经前期和绝经后乳腺癌病人.在TAM的临床及实验室研究中,常需对生物样品中的TAM进行快速测定.为了简化样品制备过程,缩短分析时间,本文对测定TAM的LC-MS-MS定量方法进行了研究.     

五种补肾中成药物中微量铝分析

用Ａｌ－ＣＡＳ－ＯＰ－１０分光光度法测定了五种补肾中成药中铝含量。结果表明,五种中成药中铝含量有一定的差异。本实验结果为进一步研究铝与补肾中成药的功效关系提供了有用数据。     

微量热法研究Schiff碱钴配合物的抗菌活性

微量热法研究Ｓｃｈｉｆｆ碱钴配合物的抗菌活性黄在银＊屈松生冯英俞芸（武汉大学化学系武汉４３００７２）关键词二羟基苯甲醛葡萄糖Ｓｃｈｉｆ碱配合物，微量热法，抗菌活性，大肠杆菌１９９７－０８－１８收稿，１９９７－１１－０３修回国家自然科学基金及高等学校博...     

邻苯二胺产品中针状未知化合物的结构鉴定

从邻苯二胺产品中分离出一种白色针状未知化合物,用液相色谱（ＨＰＬＣ）和气相色谱（ＧＣ）鉴定其纯度后,同时进行元素、红外光谱（ＩＲ）、紫外光谱（ＵＶ）、质谱（ＭＳ）、核磁共振（ＮＭＲ）氢谱及碳谱分析。根据分析的结果进行解析,最后确定未知针状不纯物中其主成分为２,１,３－苯并硫咪唑或２,１,３－硫二氮杂茚（Ｃ６Ｈ４Ｎ２Ｓ）（２,１,３－ｂｅｎｚｏｔｈ－ｉａｄｉａｚｏｌｅ）。     

基于UHPLC-QTOF MS的PLA吸管中未知物的筛查识别

该文采集了不同的PLA吸管样品,通过迁移实验模拟PLA吸管的不同使用场景,再采用超高效液相色谱－飞行时间质谱（UHPLC－QTOF MS）技术分析PLA吸管向食品模拟液中迁移的化学物质,通过靶向筛查与非靶向筛查相结合的方式共识别出30个迁移物,不同吸管样品之间以及不同食品模拟液之间的迁移物有所差异。识别的迁移物可分为低聚物和添加剂两类,其中低聚物可视为非有意添加物,主要为聚丁二酸丁二醇酯（PBS）和丁二醇－己二酸－对苯二甲酸共聚物（PBAT）,以环状结构为主;添加剂包括抗氧剂、润滑剂和增塑剂,以及与之相关的非有意添加物（原料、杂质、副反应产物等）。所有迁移物中,仅5种在GB9685－2016的肯定列表中,其余物质采用毒理学关注阈值（TTC）方法结合Cramer决策树进行危害评估,大部分被判定为Cramer Ⅲ类（高毒）物质,需予以更多关注以确保PLA吸管使用安全。     

由黄连混合生物碱制备巴马汀

黄连混合生物碱经脱亚甲二氧基或甲氧基、加氢、甲基化及氧化反应完成生物碱转化制得巴马汀,总收率12％,其结构经1H NMR,IR和MS确证.     

Determination of paclitaxel in rat plasma by LC-MS-MS

A simple, rapid, and sensitive liquid chromatography-mass spectrometry (MS)-MS method for quantitating paclitaxel in rat plasma is developed. Liquid-liquid extraction with tert-butyl methyl ether is used for sample preparation, and docetaxel is used as the internal standard. Paclitaxel and docetaxel are separated on a C18 column and quantitated using a triple-quadrupole MS operating in positive ion electrospray selective reaction monitoring mode with a total run time of 6.0 min. The peak area of the m/z 876.3 --> 307.9 transition of paclitaxel is measured versus that of the m/z 830.3 --> 549.1 transition of docetaxel to generate the standard curve. The standard curve is linear over the concentration range of 0.2008-1004 ng/mL for rat plasma. The method has high extraction recovery (> 90%) and accuracy (> 90%), with the intra- and interday precision < 15%. Frozen stability, freeze-and-thaw stability, extracted stability, and room temperature solution stability are also examined. This assay is used to support a pharmacokinetic study of paclitaxel self-assembled nanoliposome in rats.     

Determination of linezolid in human plasma by LC-MS-MS

A rapid, sensitive and selective LC-atmospheric pressure-chemical ionization-MS-MS method for the determination of the new antimicrobial agent, linezolid, in human plasma using selected reaction monitoring (SRM) was developed. Linezolid and the internal standard were extracted from the biological samples by solid phase extraction (SPE) and analyzed on a reversed-phase Shim Pack CLC-CN, C18 column with the mobile phase of acetonitrile and 20 mM ammonium acetate solution (4 + 1 v/v). Detection was accomplished using an LCQ mass spectrometer (Finnigan), which was programmed in positive MS-MS mode to permit measurement of the fragment ions of linezolid and internal standard at m/z 296.2 and 223.2, respectively. The assay run-time was less than 3.5 min. Quantitative analysis was based on peak area ratio of linezolid to the internal standard. Calibration plots were established over the concentration range of 0.1-20 micrograms ml-1 of linezolid with the lowest detection limit of 0.05 microgram ml-1 using 10 microliters sample volume. The SPE technique quantitatively recovered linezolid and the internal standard from the plasma samples at a percentage range of 89.1-93.7%. Determination of control samples of linezolid in plasma validated the LC-MS-MS-SRM method. Intra-assay and inter-assay precision were in the range of 5.1-11.4% relative standard deviation, whereas the intra- and inter-accuracy were in the range of 97.5-114.0% of the nominal concentrations of linezolid added. The data confirmed that the plasma samples of linezolid were stable at room temperature and when stored at -20 degrees C for at least 10 d. The developed LC-MS-MS-SRM method is recommended for the determination of linezolid in human plasma.     

Determination of Gallic Acid in Rat Plasma by LC-MS-MS

Liquid chromatography–electrospray ionization tandem mass spectrometry has been used for rapid, selective, and sensitive quantitative analysis of gallic acid in rat plasma. Sample pretreatment involved a one-step extraction using ethyl acetate with protocatechic acid as internal standard. Separation was on a C₁₈ column using an isocratic mobile phase, consisting of methanol-0.1% aqueous formic acid (40:60, v/v) at 0.2 mL min⁻¹. The stability of gallic acid was evaluated in acidified and non-acidified plasma. The method was validated then successfully applied to a pharmacokinetic study in rats after oral administration of rhubarb extract.

     

Determination of Gallic Acid in Rat Plasma by LC-MS-MS

Liquid chromatography–electrospray ionization tandem mass spectrometry has been used for rapid, selective, and sensitive quantitative analysis of gallic acid in rat plasma. Sample pretreatment involved a one-step extraction using ethyl acetate with protocatechic acid as internal standard. Separation was on a C₁₈ column using an isocratic mobile phase, consisting of methanol-0.1% aqueous formic acid (40:60, v/v) at 0.2 mL min^?1. The stability of gallic acid was evaluated in acidified and non-acidified plasma. The method was validated then successfully applied to a pharmacokinetic study in rats after oral administration of rhubarb extract.     

淮山药及其种植土壤中微量元素的测定

用等离子体原子发射光谱(ICP-AES)测定了淮山药根茎及其种植土壤中的微量元素。结果表明,淮山药中含有丰富的人体必需微量元素,为淮山药产品的研究和开发提供重要的依据,也为进一步开发淮山药优良品种和平衡施肥提供科学信息和依据。     

黄连生物碱的反相高效液相-电喷雾离子阱串联质谱的研究

采用反相高效液相-电喷雾离子阱串联质谱法对由乙醇提取的黄连生物碱进行了研究.优化出了反相高效液相色谱分离黄连生物碱的条件:流动相为V(乙腈):V(H2O)(三乙胺2 mmol/L)=30:70;柱温为30℃;流速为0.5 mL/min,并结合电喷雾串联质谱检测出了黄连生物碱中的小檗碱、药根碱、巴马汀、黄连碱以及微量的表...     

Constituents of Panacis Japonici Rhizoma. VI The Structure of Chikusetsu-Saponin II,IVC

Chikusetsusaponin II and IVc, the minorsaponins of Panacis japonici rhizoma (rhizome of Panax japonicum C.A. MEYER) have been isolated. The structure of these saponins were established as being oleanolic acid-(3)-[β-D-glucopyranosyl (1→6)]-β-D-glucuronopyranoside and 20S-protopanaxatriol-6-(O-α-L-rhamnopyranosyl (1→2)-β-D-glucopyranoside]-20-O-β-D-glucopyranoside. Chikusetsusaponin II is a new structure, while chikusetsusaponin IVc is identical with ginsenoside-Re, isolated from P. ginseng C. A. MEYER.     

Determination of Armillarisin A in Rat Plasma by SPE and LC-MS-MS

A rapid, sensitive and convenient ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of armillarisin A in rat plasma. Following hydrophilic–lipophilic balance solid-phase extraction, armillarisin A and propylparaben (internal standard) were separated using a gradient elution program on a C₁₈ column and detected by mass spectrometry in the negative ion mode with the multiple reaction monitoring mode. The total chromatographic running time was short (1.8 min). The method was linear over the concentration range of 0.5–250.00 ng mL^?1 for armillarisin A. The lower limit of quantification of armillarisin A was 0.5 ng mL^?1, using as little as 100 μL plasma. The intra-day and inter-day relative standard deviations were less than 15% and the relative errors were all within 10%. The extraction recovery for armillarisin A was approximately 100%, and no absolute matrix effect was observed. Finally, the method was successfully applied to a preclinical pharmacokinetic study of armillarisin A in four rats following an intravenous administration.