Profiling of Thiol-Containing Compounds by Stable Isotope Labeling Double Precursor Ion Scan Mass Spectrometry
Profiling of Thiol-Containing Compounds by Stable Isotope Labeling Double Precursor Ion Scan Mass Spectrometry
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通过稳定同位素标记双前体离子扫描质谱分析含硫醇化合物
DOI：
10.1021/ac5023315
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发表时间：
2014-10-07
影响因子：
7.4
通讯作者：
Feng, Yu-Qi
中科院分区：
文献类型：
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作者：
Liu, Ping;Huang, Yun-Qing;Feng, Yu-Qi
在这里，我们开发了一种新的策略，同位素标记结合高效液相色谱-双前体离子扫描质谱（IL-LC-DPIS-MS）分析非靶向的含巯基化合物的分析。在该策略中，我们合成了一对同位素标记试剂（ω-溴丙酮基溴化喹啉，BQB; ω-溴丙酮基溴化喹啉-d（7），BQB-d（7）），其含有反应性基团、同位素标记的部分和可电离基团以选择性地标记含巯基的化合物。BQB和BQB-d（7）标记的化合物可以产生两个特征产物离子m/z 218和225，其含有同位素标签，因此用于质谱分析中的双前体离子扫描。具有特征质量差的峰对可以容易地从两个前体离子扫描（PIS）光谱中提取，并被分配为潜在的含硫醇候选物，这有利于分析物的鉴定。BQB和BQB-d（7）标记的含巯基化合物可以通过生成两个单独的离子色谱图来清楚地区分。因此，来自用不同同位素试剂标记的两个样品的含硫醇化合物同时电离，但通过质谱法分别记录，通过消除来自两个标记样品的MS响应波动和相互干扰，提供良好的鉴定和准确的定量。使用IL-LC-DPIS-MS策略，我们分析了啤酒和人尿液中的含巯基化合物，并在啤酒和人尿液中分别发现了21和103个巯基候选物。此外，通过与硫醇标准品或串联质谱分析的进一步比较，成功地鉴定了啤酒和人尿液中的9和17个硫醇候选物。总之，IL-LC-DPIS-MS方法被证明是一种有前途的策略，在代谢组学研究中具有相同基团的化合物的分析。
Here we developed a novel strategy of isotope labeling in combination with high-performance liquid chromatography-double precursor ion scan mass spectrometry (IL-LC-DPIS-MS) analysis for nontargeted profiling of thiol-containing compounds. In this strategy, we synthesized a pair of isotope labeling reagents (omega-bromoacetonylquinolinium bromide, BQB; omega-bromoacetonylquinolinium-d(7) bromide, BQB-d(7)) that contain a reactive group, an isotopically labeled moiety, and an ionizable group to selectively label thiol-containing compounds. The BQB and BQB-d(7) labeled compounds can generate two characteristic product ions m/z 218 and 225, which contain an isotope tag and therefore were used for double precursor ion scans in mass spectrometry analysis. The peak pairs with characteristic mass differences can be readily extracted from the two precursor ion scan (PIS) spectra and assigned as potential thiol-containing candidates, which facilitates the identification of analytes. BQB and BQB-d(7) labeled thiol-containing compounds can be clearly distinguished by generating two individual ion chromatograms. Thus, thiol-containing compounds from two samples labeled with different isotope reagents are ionized at the same time but recorded separately by mass spectrometry, offering good identification and accurate quantification by eliminating the MS response fluctuation and mutual interference from the two labeled samples. Using the IL-LC-DPIS-MS strategy, we profiled the thiol-containing compounds in beer and human urine, and 21 and 103 thiol candidates were discovered in beer and human urine, respectively. In addition, 9 and 17 thiol candidates in beer and human urine were successfully identified by further comparison with thiol standards or tandem mass spectrometry analysis. Taken together, the IL-LC-DPIS-MS method is demonstrated to be a promising strategy in the profiling of compounds with identical groups in metabolomics study.