High Resolution Nuclear Magnetic Resonance Spectroscopy on Biological Tissue and Metabolomics

High-resolution nuclear magnetic resonance (NMR) spectroscopy is a universal analytical tool. It can provide detailed information on chemical shifts, J coupling constants, multiplet patterns, and relative peak areas. It plays an important role in the fields of chemistry, biology, medicine, and pharmacy. A highly homogeneous magnetic field is a prerequisite for excellent spectral resolution. However, in some cases, such as in vivo and ex vivo biological tissues, the magnetic field inhomogeneity due to magnetic susceptibility variation in samples is unavoidable and hard to eliminate by conventional methods. The techniques based on intermolecular multiple quantum coherences and conventional single quantum coherence can remove the influence of the field inhomogeneity effects and be applied to obtain high-resolution NMR spectra of biological tissues, including in vivo animal and human tissues. Broadband H-1 homo-decoupled NMR spectroscopy displays J coupled resonances as collapsed singlets, resulting in highly resolved spectra. It can be used to acquire high-resolution spectra of some pharmaceuticals. The J-difference edited spectra can be used to detect J coupled metabolites, such as gamma-aminobutyric acid, the detection of which is interfered by intense neighboring peaks. High-resolution H-1 NMR spectroscopy has been widely utilized for the identification and characterization of biological fluids, constituting an important tool in drug discovery, drug development, and disease diagnosis.