THis is a remarkable paper demonstrating the power of DNP-NMR spectroscopy. Insect wings are not isotopically labeled but yet, with DNP it is possible to record 2D 13C/13C correlation spectra in minutes.
Mentink-Vigier, Frédéric, Samuel Eddy, and Terry Gullion. “MAS-DNP Enables NMR Studies of Insect Wings.” Solid State Nuclear Magnetic Resonance 122 (December 2022): 101838.
https://doi.org/10.1016/j.ssnmr.2022.101838.
NMR is a valuable tool for studying insects. Solid-state NMR has been used to obtain the chemical composition and gain insight into the sclerotization process of exoskeletons. There is typically little difficulty in obtaining sufficient sample quantity for exoskeletons. However, obtaining enough sample of other insect components for solid-state NMR experiments can be problematic while isotopically enriching them is near impossible. This is especially the case for insect wing membranes which is of interest to us. Issues with obtaining sufficient sample are the thickness of wing membranes is on the order of microns, each membrane region is surrounded by veins and occupies a small area, and the membranes are separated from the wing by physical dissection. Accordingly, NMR signal enhancement methods are needed. MAS-DNP has a track record of providing significant signal enhancements for a wide variety of materials. Here we demonstrate that MAS-DNP is useful for providing high quality one-dimensional and two-dimensional solidstate NMR spectra on cicada wing membrane at natural isotopic abundance.