Institute of Organic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany.
Hamburg School of Food Science - Institute of Food Chemistry, University of Hamburg, Grindelallee 117, 20146, Hamburg, Germany.
Sci Rep. 2023 Sep 22;13(1):15834. doi: 10.1038/s41598-023-43056-3.
Not only in metabolomics studies, but also in natural product chemistry, reliable identification of metabolites usually requires laborious steps of isolation and purification and remains a bottleneck in many studies. Direct metabolite identification from a complex mixture without individual isolation is therefore a preferred approach, but due to the large number of metabolites present in natural products, this approach is often hampered by signal overlap in the respective H NMR spectra. This paper presents a method for the three-dimensional mathematical correlation of NMR with MS data over the third dimension of the time course of a chromatographic fractionation. The MATLAB application SCORE-metabolite-ID (Semi-automatic COrrelation analysis for REliable metabolite IDentification) provides semi-automatic detection of correlated NMR and MS data, allowing NMR signals to be related to associated mass-to-charge ratios from ESI mass spectra. This approach enables fast and reliable dereplication of known metabolites and facilitates the dynamic analysis for the identification of unknown compounds in any complex mixture. The strategy was validated using an artificial mixture and further tested on a polar extract of a pine nut sample. Straightforward identification of 40 metabolites could be shown, including the identification of β-D-glucopyranosyl-1-N-indole-3-acetyl-N-L-aspartic acid (1) and N-(2-hydroxy-2-carboxymethylsuccinyl)-L-arginine (2), the latter being identified in a food sample for the first time.
不仅在代谢组学研究中，而且在天然产物化学中，可靠地鉴定代谢物通常需要繁琐的分离和纯化步骤，这仍然是许多研究的瓶颈。因此，直接从复杂混合物中进行代谢物的非分离鉴定是首选方法，但由于天然产物中存在大量的代谢物，这种方法通常受到各自核磁共振（NMR）光谱中信号重叠的阻碍。本文提出了一种在色谱馏分的时间过程的第三维上对 NMR 与 MS 数据进行三维数学相关的方法。MATLAB 应用程序 SCORE-metabolite-ID（用于可靠代谢物鉴定的半自动相关分析）提供了相关 NMR 和 MS 数据的半自动检测，允许将 NMR 信号与 ESI 质谱中的相关质荷比相关联。该方法可快速可靠地对已知代谢物进行去重复，并有助于对任何复杂混合物中未知化合物的动态分析进行鉴定。该策略使用人工混合物进行了验证，并进一步在松仁样品的极性提取物上进行了测试。可以显示出 40 种代谢物的直接鉴定，包括β-D-吡喃葡萄糖基-1-N-吲哚-3-乙酰基-N-L-天冬氨酸（1）和 N-（2-羟基-2-羧甲基琥珀酰基）-L-精氨酸（2）的鉴定，后者首次在食品样品中被鉴定出来。
