New features of arabinoxylan ethers revealed by using multivariate analysis

Filip Nylander; Olof Svensson; Mats Josefson; Anette Larsson; Gunnar Westman

doi:10.1016/j.carbpol.2018.09.062

New features of arabinoxylan ethers revealed by using multivariate analysis

Carbohydr Polym. 2019 Jan 15:204:255-261. doi: 10.1016/j.carbpol.2018.09.062. Epub 2018 Sep 28.

Authors

Filip Nylander¹, Olof Svensson², Mats Josefson², Anette Larsson³, Gunnar Westman⁴

Affiliations

¹ Organic Chemistry, Chemistry and Biochemistry, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96, Göteborg, Sweden.
² Pharmaceutical Technology and Development, AstraZeneca R&D, SE-431 83, Mölndal, Sweden.
³ Pharmaceutical Technology, Applied Chemistry, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96, Göteborg, Sweden; SuMo BIOMATERIALS, VINN Excellence Centre, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
⁴ Organic Chemistry, Chemistry and Biochemistry, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96, Göteborg, Sweden. Electronic address: Westman@chalmers.se.

PMID: 30366539
DOI: 10.1016/j.carbpol.2018.09.062

Abstract

Hemicelluloses are a relatively unused renewable resource. One reason is their broad structure variety that makes it hard to understand structure-property relations. In this study arbinoxylan, extracted from barley husk, was chemically modified into hydroxypropyl methyl-, hydroxypropyl- and methyl arabinoxylan. The relationship between structure and phase behavior was investigated by using multivariate analysis. The arabinoxylan ethers were characterized using mid-infrared FTIR spectroscopy and from principal components analysis, PCA, structural or physical variations between samples were visualized. With orthogonal projections to latent structures, OPLS, vibrations specific for arabinoxylan hydroxypropyl and methyl substitutions was assigned. Among the observed differences between chemical derivatives was an intensity change in the water vibration. The differences in hydration were related to clouding phase behavior of the arabinoxylan ethers. This study shows that multivariate analysis methods are useful for finding unexpected and/or hidden features in the polysaccharide structure.

Keywords: Arabinoxylan; FTIR; Hemicelluloses; Hydroxypropylation; Methylation; Multivariate analysis; OPLS; PCA.