State Key Laboratory of Organometallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Shimadzu Research Laboratory (Shanghai) Co. Ltd., Shanghai 201206, China.
Anal Chem. 2021 Oct 12;93(40):13589-13596. doi: 10.1021/acs.analchem.1c02691. Epub 2021 Oct 1.
Stereospecific recognition of amino acids (AAs) plays a crucial role in chiral biomarker-based diagnosis and prognosis. Separation of AA enantiomers is a long and tedious task due to the requirement of AA derivatization prior to the chromatographic or electrophoretic steps which are also time-consuming. Here, a mass-tagged chiral selector named []/[]-estradiol-3-benzoate-17β-chloroformate ([]/[]-17β-EBC) with high reactivity and good enantiomeric resolution in regard to AAs was developed. After a quick and easy chemical derivatization step of AAs using 17β-EBC as the single chiral selector before ion mobility-mass spectrometry analysis, good enantiomer separation was achieved for 19 chiral proteinogenic AAs in a single analytical run (∼2 s). A linear calibration curve of enantiomeric excess was also established using []/[]-17β-EBC. It was demonstrated to be capable of determining enantiomeric ratios down to 0.5% in the nanomolar range. 17β-EBC was successfully applied to investigate the absolute configuration of AAs among peptide drugs and detect trace levels of d-AAs in complex biological samples. These results indicated that []/[]-17β-EBC may contribute to entail a valuable step forward in peptide drug quality control and discovering chiral disease biomarkers.
手性氨基酸（AAs）的立体特异性识别在基于手性生物标志物的诊断和预后中起着至关重要的作用。由于在色谱或电泳步骤之前需要对 AA 进行衍生化，这是一个冗长而繁琐的任务，因此 AA 对映体的分离也是如此。在这里，开发了一种具有高反应性和良好手性分辨能力的质谱标记手性选择剂，名为[]/[]-雌二醇-3-苯甲酸-17β-氯甲酸酯（[]/[]-17β-EBC）。在使用 17β-EBC 作为单一手性选择剂对 AA 进行快速简便的化学衍生化步骤之后，在单个分析运行（约 2 s）中实现了 19 种手性蛋白氨基酸的良好对映体分离。还使用[]/[]-17β-EBC 建立了对映过量的线性校准曲线。结果表明，它能够在纳摩尔范围内测定低至 0.5%的对映体比。17β-EBC 成功地应用于研究肽药物中 AA 的绝对构型，并检测复杂生物样品中痕量的 d-AA。这些结果表明，[]/[]-17β-EBC 可能有助于在肽药物质量控制和发现手性疾病生物标志物方面取得有价值的进展。
