Oral 23rd International Society of Magnetic Resonance Conference 2023

A singlet-filtered NMR method for analyzing complex mixture samples (#94)

Chengda Huang 1 , Yuqing Huang 1 , Zhong Chen 1
  1. Xiamen University, Xiamen, Fujian, China

Proton nuclear magnetic resonance (1H NMR) spectroscopy presents a non-invasive detection method for molecular structure elucidation and composition determination. However, in practical applications, 1H NMR experiments generally confront with the challenge of spectral congestion caused by abundant observable compositions and intrinsic limitations of narrow frequency distribution range and extensive J coupling splitting. Herein, based on the signal filtering mechanism of endogenous spin singlet states, we propose a 1D general NMR method, termed SF-TOCSY (Singlet-Filtered TOtal Correlation SpectroscopY), to overcome the challenge of spectral congestion and individually record the signals of targeted composition, thus suitable for high-resolution detections on complex chemical and biological mixture samples. Nuclear spin singlet states, known as effective spin-0 states, can be generated from a pair of coupled protons.1 According to the signal filtering characteristic of singlet states, we can selectively preserved the singlet state signals of the desired coupled proton pair and filter out other undesired background signals2,3. Additionally, the TOCSY block is further combined with the singlet-filtered module in the SF-TOCSY to transfer the full correlation from the selected coupled proton pair to the whole molecule, thus applicable to component identification and mixture separation in complex chemical and biological samples. The applicability of the SF-TOCSY method is demonstrated by diverse practical samples, including complex mixture solution, biological samples of in vitro pig brain tissue suffering from intrinsic magnetic field inhomogeneity, and human serum containing abundant metabolite compositions. In these experiments, it suggests that the proposed method allows one to perform targeted probing of chemical compositions for analyzing complex chemical solution mixtures containing crowded NMR resonances, even biological samples with abundant metabolites and intrinsic field inhomogeneity. Therefore, this method may provide a promising detection tool for component separation and determination in complex biological and chemical mixture samples.

Keywords: NMR spectroscopy; signal filtering; complex mixtures; spectral congestion; Targeted probing.

  1. Malcolm H. Levitt. et al. J. Am. Chem. Soc., 126, 6228-6229 (2004).
  2. Salvatore Mamone. et al. Sci. Adv., 6, eaaz1955 (2020).
  3. Huang, C.D. et al. Chem., 94, 4201-4208 (2022).