Complete Assignment of the CP/MAS ¹³C NMR Spectrum of Cellulose IIII

For the assignment of 13 C resonance for C2, C3, and C5 of cellulose III I, 13 C-enriched celluloses were biosynthesized by Acetobacter xylinum ( A. xylinum ) ATCC10245 in the culture medium containing d -(2- 13 C), d -(3- 13 C), or d -(5- 13 C)glucose. After the 13 C-enriched celluloses and Cladophora cellulose were converted into III I allomorph by the ethylenediamine treatment, cross-polarization/magic angle spinning (CP/MAS) 13 C NMR spectra of these cellulose III I samples were measured. By comparison of the CP/MAS 13 C NMR spectrum of Cladophora cellulose sample with those of the 13 C-enriched celluloses, 13 C resonance lines of the cellulose III I were completely assigned for the first time. As a result, all carbons of cellulose III I were shown in singlet in the CP/MAS spectrum of cellulose III I, which suggests that cellulose III I is made up of one kind of glucopyranose residue.