1H NMR spectra of branched-chain cyclomaltohexaoses (alpha-cyclodextrins)

The 1H NMR spectra of seven branched alpha-cyclodextrins (alpha-CDs) were observed and analyzed in detail. They were compared with spectra of alpha-CD and amylose. Although these branched alpha-CDs consist only of alpha-D-glucose with the same alpha-(1-->4) O-glucosyl binding, aside from one exception, differences in chemical shifts of corresponding signals were significantly large. Especially, differences in the chemical shift in anomeric protons were considerably large. Subtle differences in glucosyl binding directly influences chemical shifts of these protons because anomeric protons are located adjacent to the glucosyl binding sites.