Zhejiang Provincial Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis, Institute of Mass Spectrometry, School of Material Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315211, China.
Zhejiang Provincial Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis, Institute of Mass Spectrometry, School of Material Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315211, China.
Anal Chim Acta. 2022 Sep 22;1227:340298. doi: 10.1016/j.aca.2022.340298. Epub 2022 Aug 22.
The separation of chiral amino acids (AAs) and their derivatives has always been a research difficulty in the field of biochemistry due to the high similarity of enantiomeric structures. In this work, a simple and quick method using natamycin (Nat) as chiral selector has been developed to simultaneously separate chiral AAs and their derivatives of carbobenzoxy/benzyl-AAs (Cbz/Bzl-AAs) by trapped ion mobility spectrometry-mass spectrometry (TIMS-MS). Specifically, 12 groups of the Cbz-AAs and Bzl-AAs can get baseline mobility separation by simple mixing with Nat to form binary diastereomeric complex ions [Nat+(Cbz-D/L-AA)+H] and [Nat+(Bzl-D/L-AA)+H]. While for the remained 5 groups of Bzl-D/L-AAs and 16 groups of D/L-AAs with unsatisfying separation, by further adding P-toluenesulfonic acid (PTS), the formed ternary complexes can allow their baseline chiral separation. Specifically, Bzl-D-AAs and Bzl-L-AAs get much improved separation effect by the formed diastereomeric complexes of [Nat+(Bzl-AA)+PTS+H], which the R was improved from 0 to 2.40; while the D/L-AAs can get baseline separation by the formed diastereomeric complexes of [Nat + AA + PTS + H], [Nat + AA+(PTS)+H], and [Nat+(AA)+(PTS)+H], with the R ranged from 0.44 to 3.53. Definitely, PTS is the first time reported as the ligand to improve the separation effect for the enantiomers, and with the higher assembly of chiral analyte, Nat, and PTS might enable better chiral separation for the chiral amino acid and their derivatives. Moreover, method validation of relative quantification and accuracy for the D/L-AA and their derivatives were measured in a mixture, yielding R greater than 0.99 and RSD% ≤ 2.68%. Overall, Nat and PTS as chiral selector and ligand can be widely used for chiral AAs and their derivatives mobility separation, and potentially for the separation of other AA-related chiral molecules.
手性氨基酸（AAs）及其衍生物的分离一直是生物化学领域的研究难点，因为其对映异构体结构高度相似。在这项工作中，我们开发了一种简单快速的方法，使用纳他霉素（Nat）作为手性选择剂，通过离子淌度谱-质谱联用（TIMS-MS）同时分离手性氨基酸及其衍生物的碳二亚胺/苄基-AAs（Cbz/Bzl-AAs）。具体来说，通过简单地将 12 组 Cbz-AAs 和 Bzl-AAs 与 Nat 混合，可以形成二元非对映体复合物离子[Nat+（Cbz-D/L-AA）+H]+和[Nat+（Bzl-D/L-AA）+H]+，从而实现基线迁移分离。而对于其余的 5 组 Bzl-D/L-AAs 和 16 组 D/L-AAs，分离效果不理想，通过进一步添加对甲苯磺酸（PTS），可以形成三元配合物，从而实现其基线手性分离。具体来说，Bzl-D-AAs 和 Bzl-L-AAs 通过形成非对映体复合物[Nat+（Bzl-AA）+PTS+H]+，其 R 值从 0 提高到 2.40，从而获得更好的分离效果；而 D/L-AAs 可以通过形成非对映体复合物[Nat+AA+PTS+H]+、[Nat+AA+（PTS）+H]+和[Nat+（AA）+（PTS）+H]+实现基线分离，其 R 值范围为 0.44 到 3.53。显然，PTS 是首次报道作为配体来改善对映异构体的分离效果，并且随着手性分析物、Nat 和 PTS 的更高组装，可能会对手性氨基酸及其衍生物实现更好的手性分离。此外，还在混合物中测量了相对定量和准确性的方法验证，用于 D/L-AA 及其衍生物，得到 R 大于 0.99 和 RSD%≤2.68%。总的来说，Nat 和 PTS 作为手性选择剂和配体可广泛用于手性氨基酸及其衍生物的迁移分离，并且可能用于分离其他与 AA 相关的手性分子。
