¹³C and ¹H Resonance Assignment of Mercerized Cellulose II by Two-Dimensional MAS NMR Spectroscopies

Abstract

Through-bond 13 C− 13 C and 13 C− 1 H correlations in the crystal structure of cellulose II were determined by the two-dimensional (2D) refocused INADEQUATE and MAS-J-HMQC spectra of the mercerized cellulose, which was biosynthesized by Acetobacter xylinum ATCC 10245 from the uniformly labeled glucose ( d -(U- 13 C 6 )glucose). Mercerization of the bacterial cellulose was achieved in a solution of 20% NaOH in water for 2 weeks. In the 2D INADEQUATE spectrum of cellulose II, two sets of the through-bond 13 C− 13 C connectivities from C1 through C6 were clearly observed, which enabled us to completely assign the complex 1D CP/MAS 13 C spectrum of cellulose II. Following the 13 C assignment, the 1 H resonance for the proton(s) attached to each carbon of cellulose II could be assigned by use of the 2D MAS-J-HMQC spectrum of the mercerized cellulose.