C-13 CHEMICAL-SHIFT ANISOTROPIES OF SOLID AMINO-ACIDS

An approach to spinning sideband (SSB) separation of protonated and non-protonated carbons in slow spinning conditions via dipolar dephasing is proposed. This method offers two features: SSB spectral simplification, which greatly reduces the overlaps encountered in a usual SSB spectrum, and spectral distinction of overlapped resonances for protonated and non-protonated carbons. The C-13 chemical shift anisotropies of the 20 amino acids as polycrystalline powdered solids were completely measured with the SSB intensity analyses as an application of the suggested approach.