Anal Chem. 2019 Feb 5;91(3):2304-2311. doi: 10.1021/acs.analchem.8b04928. Epub 2019 Jan 16.
Sensitivity and resolution are key considerations for NMR applications in general and for metabolomics in particular, where complex mixtures containing hundreds of metabolites over a large range of concentrations are commonly encountered. There is a strong demand for advanced methods that can provide maximal information in the shortest possible time frame. Here, we present the optimization and application of the recently introduced 2D real-time BIRD H-C HSQC experiment for NMR-based metabolomics of aqueous samples at C natural abundance. For mouse urine samples, it is demonstrated how this real-time pure shift sensitivity-improved heteronuclear single quantum correlation method provides broadband homonuclear decoupling along the proton detection dimension and thereby significantly improves spectral resolution in regions that are affected by spectral overlap. Moreover, the collapse of the scalar multiplet structure of cross-peaks leads to a sensitivity gain of about 40-50% over a traditional 2D HSQC-SI experiment. The experiment works well over a range of magnetic field strengths and is particularly useful when resonance overlap in crowded regions of the HSQC spectra hampers accurate metabolite identification and quantitation.
灵敏度和分辨率是 NMR 应用的关键考虑因素，特别是在代谢组学中，通常会遇到包含数百种代谢物且浓度范围很大的复杂混合物。人们强烈需要能够在尽可能短的时间内提供最大信息量的先进方法。在这里，我们介绍了最近引入的二维实时 BIRD H-C HSQC 实验在基于 NMR 的水相样品代谢组学中的优化和应用，该实验在 C 自然丰度下进行。对于小鼠尿液样本，本文演示了这种实时纯移相灵敏度增强的异核单量子相关方法如何在质子检测维度上提供宽带同核去耦，从而显著提高受光谱重叠影响的区域的光谱分辨率。此外，交叉峰的标量多重峰结构的塌陷导致相对于传统的 2D HSQC-SI 实验灵敏度提高约 40-50%。该实验在一系列磁场强度下均能很好地工作，特别是在 HSQC 光谱拥挤区域的共振重叠会阻碍准确的代谢物鉴定和定量时非常有用。
