Structural Aspects of Permethylated Cyclodextrins and Comparison with their Parent Oligosaccharides, as Derived from Unequivocally Assigned1H and13C NMR Spectra in Aqueous Solutions

The complete assignments of the 1H and 13C NMR spectra of α-, β- and γ-cyclodextrins (CDs) and their permethylated derivatives were derived from dedicated experiments. Existing literature data were complemented with detailed analyses, including unequivocal assignment of the methoxy groups. The structures of the macrocycles in solution, as derived from the NMR data, resemble those in the solid state. The increased distortions observed for the larger permethylated CDs are expected to affect seriously their complexing ability.