Statistical approach for solid-state NMR spectra of cellulose derived from a series of variable parameters

Abstract

Principle component analysis (PCA) was used to extract components from the solid-state nuclear magnetic resonance (NMR) spectra of bacterial cellulose (BC). Polymers such as cellulose have several domain structures, and their structure and dynamics are reflected in the variety of solid-state spectra derived from different parameters. The complexity of the obtained spectra makes the analysis of spectra from relaxation measurements difficult. Multivariate analysis, such as PCA, has been suggested as an option to improve NMR spectral analyses. In this study, we attempted to extract peak components from cross polarization (CP) experiment data from the variable contact time spectra of BC by using PCA. The extracted peaks were annotated according to previous reports, and the existence of crystalline Ia was clearly recognized. The important components of the BC structure (that is, crystalline Ia, amorphous form and mobility) were separated in the PCA-loading plot and CP curve.

Structural Study of Cellulose-Iron Oxide Composite Materials

“…C NMR spectrum of cellulose was shown with dispersion of chemical shift values: C-1 (105 ppm), C-2/C-3/C-5 (68 -78 ppm), C-4 (88.4 and 83.3 ppm), and C-6 (57 -67 ppm). The 13 C NMR spectral lines of cellulose agree with previous reports[4] [16]. Looking at different Fe coated hematite-cellulose composites and spectral trends for cellulose signatures reveal that composites with greater Fe content have weaker13 C intensity, more band broadening and wider chemical shift variations.…”

Solid-, Solution-, and Gas-state NMR Monitoring of 13C-Cellulose Degradation in an Anaerobic Microbial Ecosystem

“…The results of the present study, acquired using triple-phase NMR spectroscopy, are schematically summarized in Figure 5 and show the entire microbial anaerobic degradation process, starting with a solid biomass substrate composed of crystalline and amorphous BC and resulting in the generation of C6' C6 C2,3,5 12 C phenylacetic acid 12 C acetic acid 12 C propionic acid 13 C propionic acid 13 C acetic acid 13 biogases and low-molecular-weight soluble end products ( Figure 5). Through the thermophilic anaerobic digestion of crystalline and amorphous BC, we were able to observe one of the material circulations from solid biomass.…”

“…For example, it enables observations of crystalline and amorphous structures of cellulose, although not all carbon atoms such as C2, C3, and C5 that overlap in 1-dimensional 13 C-NMR spectra can be identified. In solid-state NMR, cross-polarization (CP)/magic angle spinning (MAS) is frequently used to analyze the supermolecular structures of cellulose in order to characterize the differences between crystalline and amorphous forms [9][10][11][12].…”

“…C-labeled BC was produced by cultures of G. xylinus supplemented with 13 C 6 -glucose ( 13 C > 99%) purchased from Cambridge Isotope Laboratories (Andover, MA, USA) as described previously [9][10][11][12]. The pellicles of 13 C-BC produced by G. xylinus were converted into powder using an automill machine (Tokken Inc., Chiba, Japan).…”

Differences in Cellulosic Supramolecular Structure of Compositionally Similar Rice Straw Affect Biomass Metabolism by Paddy Soil Microbiota

“…Okushita et al investigated structural changes in bacterial cellulose by subjecting ionic liquids to solid- and solution-state NMR and FTIR. The data were then profiled using principal components analysis (PCA) [39], [40]. Watanabe et al profiled the tissue-specific biomass of Jatropha curcas using FTIR and solution-state NMR [41].…”