应用nanoLC-MS/MS分析毛白杨次生维管系统的蛋白质表达谱

基于1DE的nanoLC-MS/MS方法分析毛白杨次生维管系统的蛋白质组,成功鉴定:14个蛋白质参与细胞分裂,7个转录因子,22个与细胞骨架相关蛋白质,31个与细胞信号转导相关蛋白质,14个与细胞壁相关蛋白质.显示这些蛋白质相应基因参与形成层活动的调控,为进一步了解木材形成的分子机制奠定基础.     

LC-MS/MS法研究甲磺隆和氯磺隆在不同条件土壤中的残留行为

在建立液相色谱三重串联四极杆质谱（LC-MS/MS）检测技术的基础上,采用PVC材料的圆柱形盆钵栽培方法,研究了不同土壤环境条件下甲磺隆和氯磺隆的残留特性。结果表明,甲磺隆和氯磺隆在水稻根际和非根际土壤中的残留量均呈不断下降趋势。处理后15d,根际和非根际土壤中两种农药残留量分别下降了44.7%和41.5%（甲磺隆）及38.7%和40.1%（氯磺隆）,根际和非根际的残留差异不显著（P〉0.05）;处理后31d,残留量分别下降了77.7%和64.8%（甲磺隆）及62.7%和50.1%（氯磺隆）,差异达极显著水平（P〈0.01）;处理后63d,残留量分别下降了96.4%和85.1%（甲磺隆）及90.0%和79.4%（氯磺隆）,残留差异达极显著水平（P〈0.01）。甲磺隆的降解趋势和氯磺隆基本一致,但下降幅度比氯磺隆大。二者在水稻根际和非根际土壤中的残留量均符合一级动力学方程式C=C0e-λ（tC代表浓度;C0代表初始浓度;t时间）,决定系数范围在0.9342～0.9957之间。在种植水稻的条件下,下层土的农药残留量呈先上升后下降的趋势,处理后数日内达最高点,之后不断下降,122d后低于检测限。水稻下层土残留的从无到有说明农药在土壤中的淋溶可能是水田环境农药残留降解的原因之一。干旱土壤条件下,土壤的淋溶作用不明显。说明水旱轮作有利于农药残留在土壤环境中的降解。     

水产品中红霉素残留分析的现状

介绍了红霉素的特性、水产品中红霉素残留对人体所产生的副作用以及目前国内外主要的分析检测方法和技术,包括微生物法、薄层色谱法、高效液相色谱法以及色／质联用法。同时,对水产品中红霉素残留分析的前景进行了展望。     

莲种胚发育过程中胚胎晚期丰度蛋白基因表达量与种子含水量相关性分析

通过莲胚形态观察、生理指标测定、蛋白质谱鉴定与基因表达量分析，筛选出莲胚脱水成熟过程中显著富集的LEA蛋白(late embriogenesis abundant protein)，并分析其基因表达量与含水量的相关性。结果表明，莲胚发育成熟共需约30 d，形态发育15~18 d，随后进入脱水成熟阶段。在种胚脱水阶段种胚含水量由80%下降到6.7%，细胞内蛋白含量上升2.75倍。对不同脱水阶段莲胚进行蛋白单向电泳，筛选出7条显著富集的蛋白条带，其中包含7种LEA家族蛋白:EMB564-like、Dehydrin Rab18、Lea14-A与4种D-34类蛋白。Dehydrin Rab18、D-34、D-34-like-1表达量随莲胚脱水而递增，与种子含水量呈负相关；EMB564-like、Lea14-A、D-34-like-2、D-34-like-3基因表达水平呈单峰曲线，在莲胚发育20 d时达到峰值。其中Dehydrin Rab18、EMB564-like与D-34-like-2在莲胚脱水阶段上调表达幅度最大，表达量分别是莲胚脱水前的38.7、11.5、19.0倍，可能与莲胚的逆境保护与耐储存机制相关。     

LC-MS/MS结合定量触发相关MS/MS扫描功能同时定性确证和定量测定饲料中的违禁药物喹乙醇

本实验利用定量触发相关MS/MS扫描(QED-MS/MS)功能,建立饲料中喹乙醇的同时定性确证和定量测定LC-MS/MS方法。饲料中喹乙醇经5%甲醇-水溶液提取,Oasis HLB固相萃取柱净化后,通过LC-MS/MS分析。LC-MS/MS采用Zorbax SB C18柱(3.5μm,2.1×150 mm),0.2%乙酸-甲醇梯度洗脱,加热电喷雾离子化,选择性反应监测m/z 264>212作为定量测定,同时以数据依赖扫描模式对m/z 150～265扫描,作为定性确证结果。结果表明:本方法在0.2～10 mg/kg范围内线性关系良好,最低同时定性定量限为0.2 mg/kg。因此基于QED-MS/MS的LC-MS/MS方法可用于饲料中喹乙醇的检测。     

QuEChERS-高效液相色谱-串联质谱法分析甘蓝和土壤中的鱼藤酮

采用QuEChERS-液相色谱-串联质谱法(QuEChERS and LC-MS/MS)建立了鱼藤酮在甘蓝及土壤中的残留检测方法。样品前处理采用以乙腈作提取剂、PSA(primary sec-ondary amine,N-丙基乙二胺)为分散净化剂的QuEChERS方法,利用高效液相色谱-串联质谱(HPLC-MS/MS)在多反应离子检测模式下进行检测。在甘蓝和土壤中的添加水平为0.002-0.1mg/kg条件下,鱼藤酮在甘蓝中的添加回收率为78.36%～88.16%(相对标准偏差为6.05%～13.38%),在土壤中的添加回收率为77.94%～89.50%(相对标准偏差为4.70%～12.35%)。鱼藤酮在甘蓝和土壤中的最低检测浓度为0.002mg/kg,最小检出量为1.0×10-11g。该方法样品前处理简单、快速,准确度、精密度和灵敏度均符合农药残留检测要求,适用于甘蓝和土壤中鱼藤酮残留的检测。     

基于代谢组学的云南白茶与福鼎白茶化学成分比较分析

为了探明云南白茶与福鼎白茶的化学物质差异,以9个云南白茶茶样和6个福鼎白茶茶样为研究对象,采用基于超高效液相色谱-四极杆-静电轨道阱质谱（UHPLC-Q-Exactive/MS）的代谢组学方法并结合感官审评分析对其非挥发性化学成分进行系统研究。本研究共鉴定出109个化合物,包括儿茶素类、二聚儿茶素类、黄酮糖苷类（黄酮-O-糖苷和黄酮-C-糖苷）、N-乙基-2-吡咯烷酮取代的儿茶素类、氨基酸类、酚酸类、有机酸类、生物碱类、脂质类等。偏最小二乘法判别分析和热图分析表明,云南白茶和福鼎白茶的化学成分存在较大差异,共得到46个具有组间显著性差异的化合物（P<0.05）,其中表型儿茶素类、二聚儿茶素类、部分黄酮糖苷类（山柰酚-3-半乳糖苷、槲皮素-3-葡萄糖苷等）、酚酸类、有机酸类、脂类等化合物在云南白茶中含量较高;非表型儿茶素类、部分黄酮糖苷类（槲皮素-3-半乳糖苷、杨梅素-3-半乳糖苷等）、氨基酸类、生物碱类化合物在福鼎白茶中含量相对较高,推测主要受茶树品种和干燥工艺的影响。本研究可为全面了解和认识两地白茶的化学物质基础和风味品质差异及其产地鉴别提供理论参考。     

A Collaborative Evaluation of LC-MS/MS Based Methods for BMAA Analysis: Soluble Bound BMAA Found to Be an Important Fraction

Exposure to β-N-methylamino-l-alanine (BMAA) might be linked to the incidence of amyotrophic lateral sclerosis, Alzheimer’s disease and Parkinson’s disease. Analytical chemistry plays a crucial role in determining human BMAA exposure and the associated health risk, but the performance of various analytical methods currently employed is rarely compared. A CYANOCOST initiated workshop was organized aimed at training scientists in BMAA analysis, creating mutual understanding and paving the way towards interlaboratory comparison exercises. During this workshop, we tested different methods (extraction followed by derivatization and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis, or directly followed by LC-MS/MS analysis) for trueness and intermediate precision. We adapted three workup methods for the underivatized analysis of animal, brain and cyanobacterial samples. Based on recovery of the internal standard D₃BMAA, the underivatized methods were accurate (mean recovery 80%) and precise (mean relative standard deviation 10%), except for the cyanobacterium Leptolyngbya. However, total BMAA concentrations in the positive controls (cycad seeds) showed higher variation (relative standard deviation 21%–32%), implying that D₃BMAA was not a good indicator for the release of BMAA from bound forms. Significant losses occurred during workup for the derivatized method, resulting in low recovery (<10%). Most BMAA was found in a trichloroacetic acid soluble, bound form and we recommend including this fraction during analysis.     

Clinical Pharmacokinetics and Effects of Vincristine Sulfate in Dogs with Transmissible Venereal Tumor (TVT)

This study was conducted to evaluate the pharmacokinetic characteristics of vincristine and their correlation with its clinical effects in dogs with transmissible venereal tumor (TVT). Dogs with TVT were intravenously administered vincristine sulfate at a dose of 0.7 mg/m² of body surface area. Blood samples were collected starting from 5 min to 48 hr after drug administration. The plasma concentration of vincristine was determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The pharmacokinetic parameters of vincristine were characterized using a two-compartmental pharmacokinetic model. The volume of distribution, distribution half-life, elimination half-life and plasma clearance were 0.660 ± 0.210 l/kg, 21.5 ± 6.90 min, 47.6 ± 14.2 min and 0.010 ± 0.001 l/min/kg, respectively. Tumor regression was determined at weekly interval by a physical examination and histopathological analysis. In our study, three to eight administrations of vincristine at a dose of 0.7 mg/m² were able to induce a complete tumor regression without any evidence of gross lesion of disease. Therefore, this investigation provides the pharmacokinetic characteristics of vincristine in dogs with TVT, which may be used as an integration tool to gain a better understanding of the disposition properties of the drug and the correlation of these properties with the drug’s clinical effects. In addition, we validated the LC-MS/MS method and found that it is suitable for the pharmacokinetic study of vincristine in dog plasma.     

小麦多子房和单子房性状的差异蛋白质组学研究

小麦多子房性状的蛋白质组学特性和形成机制及其在小麦杂种优势中的应用可能提供理论依据。为揭示以小麦单子房品系77(2)及其多子房近等基因系Mu77(2)为材料, 采用TCA-丙酮法提取穗分化至四分体时期的幼穗总蛋白, 并通过IEF/SDS-PAGE双向凝胶电泳分离, 获得了分辨率和重复性较好的蛋白质组差异图谱。在等电点4~7、分子量14.4~97.4 kD之间发现约450个肉眼可辨的蛋白点, 其中上调2倍以上且达到99%统计学显著水平的差异表达蛋白点30个。对6个特异性差异蛋白点作二级质谱(LC-MS/MS)分析, 结果表明它们是富含甘氨酸RNA结合蛋白(S1)、SGT1-1(S2)、HMG-I/Y(S3)、谷胱甘肽转移酶(S4)、果糖1,6-二磷酸醛缩酶(S5)和未知蛋白(S6)。这些蛋白质对DNA转录、蛋白质翻译、能量转换及代谢、抗逆防卫等生理生化过程起调控作用, 可能与小麦多子房性状的形成有关。