Solid-state ¹⁷O NMR study of α-d-glucose: exploring new frontiers in isotopic labeling, sensitivity enhancement, and NMR crystallography

Abstract

We report synthesis and solid-state 17O NMR characterization of α-D-glucose for which all six oxygen atoms are site-specifically 17O-labeled. Solid-state 17O NMR spectra were recorded for α-D-glucose/NaCl/H2O (2/1/1) cocrystals under...

Benchmark accuracy of predicted NMR observables for quadrupolar 14N and 17O nuclei in molecular crystals

“…Unlike diffraction methods, the CS and EFG tensors probed using ssNMR are extremely sensitive to hydrogen atom positions and are well‐suited to examining dynamics. Many nuclear magnetic resonance (NMR) techniques combine isotropic enrichment strategies with methods designed for spin‐1/2 nuclei such as 13 C or 15 N. However, a growing body of research shows that quadrupolar nuclei such as 17 O and 14 N provide valuable insight in both biological and pharmaceutical applications [1–6] …”

“…Natural‐abundance 17 O NMR spectroscopy has been used to gain insight into the ordering of water molecules across the lipid bilayer [7] . In a recent study, involving ‐ ‐glucose site‐specific 17 O‐labeling coupled with recent advancements in ssNMR methods enabled the detection of key structural differences in the hydrogen bonding between two types of crystallographically distinct ‐ ‐glucose molecules [4] . In addition to applications in molecular crystals, 17 O ssNMR can provide valuable insight into enzyme structure and mechanism.…”

Residue-Specific High-Resolution 17O Solid-State Nuclear Magnetic Resonance of Peptides: Multidimensional Indirect 1H Detection and Magic-Angle Spinning

“…Magnetic fields up to 35.2 T have provided dramatic enhancements in spectral resolution and sensitivity through reduction of the secondorder quadrupolar broadening, as illustrated in spectra of peptides and metal−organic frameworks (MOFs). 2,6,8,13,14 Third, cryogenic magic-angle spinning (MAS) probes and dynamic nuclear polarization have recently been used to yield a multifold increase in much needed spectral sensitivity. 6,15,16 Finally, solid-state NMR methods such as multiple-quantum magic-angle spinning (MQMAS) 17 and satellite-transition magic-angle spinning (STMAS) 18 which provide high-resolution isotropic spectra of half-integer quadrupolar nuclei are becoming increasingly popular for 17 O experiments.…”

“…2,6,8,13,14 Third, cryogenic magic-angle spinning (MAS) probes and dynamic nuclear polarization have recently been used to yield a multifold increase in much needed spectral sensitivity. 6,15,16 Finally, solid-state NMR methods such as multiple-quantum magic-angle spinning (MQMAS) 17 and satellite-transition magic-angle spinning (STMAS) 18 which provide high-resolution isotropic spectra of half-integer quadrupolar nuclei are becoming increasingly popular for 17 O experiments.…”

“…However, in the past few years, several approaches have been reported to address these obstacles. First, new methods to 17 O label peptides and carbohydrates using synthetic and acid-catalyzed exchange methods have been reported. − Notably, 17 O labeled amino acids have been selectively incorporated into recombinant proteins making 17 O NMR feasible for biomacromolecules. , Recently, mechanochemistry has also been shown to be a robust and economic method for 17 O enrichment of a variety of compounds. − Second, higher field NMR magnets and instrumentation have also contributed greatly to facilitating 17 O NMR spectroscopy. Magnetic fields up to 35.2 T have provided dramatic enhancements in spectral resolution and sensitivity through reduction of the second-order quadrupolar broadening, as illustrated in spectra of peptides and metal–organic frameworks (MOFs). ,,,, Third, cryogenic magic-angle spinning (MAS) probes and dynamic nuclear polarization have recently been used to yield a multifold increase in much needed spectral sensitivity. ,, Finally, solid-state NMR methods such as multiple-quantum magic-angle spinning (MQMAS) and satellite-transition magic-angle spinning (STMAS) which provide high-resolution isotropic spectra of half-integer quadrupolar nuclei are becoming increasingly popular for 17 O experiments.…”