13C Solid-State Cross Polarization/Magic-Angle-Spinning Nuclear Magnetic Resonance Spectra of Natural and Synthetic Melanins

The availability of NMR spectrometers operating in cross polarization/magic angle spinning (CP-MAS) has provided a powerful tool for the structural elucidation of insoluble materials. In this ¹³C NMR study of eumelanins we report the first direct evidence of the presence of different chemical functionalities in synthetic and natural eumelanins. These spectra contain useful information for the characterization of melanins from different sources.