Applications of New Mass Spectral Techniques

新质谱技术的应用

• 批准号: 7290813
• 负责人: james a kelley
• 金额: --
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7290813
• 关键词: Applications; New; Mass; Spectral; Techniques

The objective of this project is development of new mass spectral techniques in order to provide innovative and/or more rapid solutions to problems involving (1) chemical structure determination, (2) complex mixture analysis and (3) measurement of trace components in biological systems. Matrix-assisted laser desorption ionization (MALDI) mass spectrometry, electrospray ionization mass spectrometry (ESI/MS), tandem mass spectrometry (MS/MS), combined liquid chromatography-mass spectrometry (LC/MS), combined capillary electrophoresis-mass spectrometry (CE/MS) and accurate mass measurement are the techniques of current interest. On-line CE sample concentration techniques with subsequent peak collection are being investigated as a preparative-scale method for the off-line combination of CE with high resolution MALDI/MS and post-source decay fragmentation analysis. The off-line combination of high-performance liquid chromatography (HPLC) with MALDI/MS is also being investigated for the analysis of complex synthetic mixtures. A number of synthetic compounds built on a constrained glycerol scaffold (disubstituted DAG-lactone) have been identified as potent agonists of protein kinase C (PK-C). Depending on the structure of the substituents comprising R1 and R2, these DAG-lactones appear to have some degree of PK-C isozyme specificity. A solid-phase combinatorial approach is being applied in the LMC to investigate chemical diversity at R1 and R2 in order to produce more specific C1 domain ligands. It is important that these synthetic libraries be rapidly characterized and their structures established before biological evaluation. Fast atom bombardment mass spectrometry (FAB/MS), flow-injection ESI/MS, flow-injection APCI/MS and MALDI/MS have been investigated as rapid mass spectral approaches for the initial characterization of these synthetic DAG-lactone libraries. One strategy for the rapid, qualitative structural characterization of these libraries employs FAB/MS mixture analysis. Because the FAB mass spectrum of a typical DAG-lactone derivative is both predictable and structurally informative, it can be used to identify the DAG-lactone derivatives present in simple mixtures. Initially, selected library components are examined individually to evaluate the efficiency of the chemistry and to confirm that mass spectra behave as predicted. Simple 4- to 6-component mixtures encompassing the entire chemical space are then assembled, analyzed and interpreted. Library components not detected during mixture analysis are subsequently analyzed individually. Mixture analysis correlates directly with individual analysis, substantially reduces the number of samples to be examined, results in enhanced analytical turn-around and is amenable to accurate mass measurement. Flow-injection ESI/MS is not suitable for analysis of these DAG-lactones because of their high lipophilicity and limited basicity. Flow injection-APCI/MS produces spectra that consist of MH+ as well as various fragment and solvent-adduct ions. This later approach appears to be complementary to FAB/MS in terms of spectral information. MALDI/MS also appears useful as a tool for the rapid characterization of these small molecule libraries although variable alkali metal ion cationization complicates spectral interpretation. Matrix-less MALDI is currently under investigation as an approach to resolve this problem and provide an even more rapid analysis approach. Our ultimate goal is the structural characterization of all 96 library components in a one day. Aliquots of each library component are being archived for possible future analysis should later biological evaluation warrant additional characterization. FAB/MS is routinely employed to support the LMC synthetic effort through structural characterization of new compounds and synthetic intermediates.

该项目的目的是开发新的质谱技术，以便为涉及的问题提供创新和/或更快的解决方案（1）化学结构确定，（2）复杂的混合物分析以及（3）生物系统中痕量成分的测量。基质辅助激光解吸电离（MALDI）质谱法，电喷雾电离质谱法（ESI/MS），串联质谱（MS/MS），液相色谱 - 液相色谱 - 质量 - 质量 - 质量光谱法（LC/MS），组合毛细管电电子群的组合（CE/MSS）和准确的量度（CE/MSS）和准确的量度。在线CE样品浓度技术和随后的峰值收集正在研究，作为一种制备尺度方法，用于使用高分辨率MALDI/MS和源后衰减碎片分析的CE离线组合。还研究了高性能液相色谱（HPLC）与MALDI/MS的离线组合，以分析复杂的合成混合物。 许多基于约束的甘油支架（DISUBSTETSTET的DAG-LACTONE）构建的合成化合物已被鉴定为蛋白激酶C（PK-C）的有效激动剂。根据包含R1和R2的取代基的结构，这些DAG-LACTONE似乎具有一定程度的PK-C同工酶特异性。在LMC中正在应用固相组合方法，以研究R1和R2的化学多样性，以产生更特定的C1结构域配体。重要的是要迅速表征这些合成文库，并在生物学评估之前建立它们的结构。快速原子轰击质谱法（FAB/MS），流动注射ESI/MS，流动注射APCI/MS和MALDI/MS作为快速质谱方法，用于初始表征这些合成DAG-LACTONE库。这些文库快速，定性结构表征的一种策略采用FAB/MS混合物分析。由于典型的DAG-LACTONE衍生物的FAB质谱既可以预测又是结构上的信息，因此它可用于识别简单混合物中存在的DAG-LACTONE衍生物。最初，对选定的库组件进行单独检查以评估化学的效率，并确认质谱的行为如所预测的。然后，组装，分析和解释简单的4到6个组分混合物，包括整个化学空间。随后分别分析混合物分析过程中未检测到的库组件。混合物分析与单个分析直接相关，大大减少了要检查的样品数量，从而增强了分析转弯，并且可以适应准确的质量测量。流动注射ESI/MS不适合分析这些DAG-LACTONE，因为它们具有高的亲脂性和有限的碱性。流动注射-APCI/MS产生由MH+以及各种片段和溶剂 - 成型离子组成的光谱。在光谱信息方面，这种后来的方法似乎与Fab/MS是互补的。 MALDI/MS似乎也可以作为这些小分子库快速表征的工具，尽管可变的碱金属离子阳离子使光谱解释复杂化。目前正在调查无基质的MALDI作为解决此问题并提供更快的分析方法的一种方法。我们的最终目标是一天中所有96个图书馆组件的结构表征。每个库组件的等分试样都被存档以进行未来的分析，以后的生物学评估应保留其他表征。 通过新化合物和合成中间体的结构表征，通常使用FAB/MS来支持LMC合成工作。