This article is a U.S. Government work and is in the public domain in the U.S.A.
Article first published online: 14 MAR 2011
Published in 2011 John Wiley & Sons, Ltd.
Rapid Communications in Mass Spectrometry
Volume 25, Issue 7, pages 941–950, 15 April 2011
How to Cite
Bowman, M. J., Dien, B. S., O'Bryan, P. J., Sarath, G. and Cotta, M. A. (2011), Selective chemical oxidation and depolymerization of switchgrass (Panicum virgatum L.) xylan with oligosaccharide product analysis by mass spectrometry. Rapid Commun. Mass Spectrom., 25: 941–950. doi: 10.1002/rcm.4949
This article was published online on 14 March 2011. An error was subsequently identified. This notice is included in the online version to indicate that it has been corrected.
- Issue published online: 17 MAR 2011
- Article first published online: 14 MAR 2011
- Manuscript Revised: 20 JAN 2011
- Manuscript Accepted: 20 JAN 2011
- Manuscript Received: 12 NOV 2010
Vol. 25, Issue 11, 1686, Article first published online: 3 MAY 2011
Xylan is a barrier to enzymatic hydrolysis of plant cell walls. It is well accepted that the xylan layer needs to be removed to efficiently hydrolyze cellulose; consequently, pretreatment conditions are (in part) optimized for maximal xylan depolymerization or displacement. Xylan consists of a long chain of β-1,4-linked xylose units substituted with arabinose (typically α-1,3-linked in grasses) and glucuronic acid (α-1,2-linked). Xylan has been proposed to have a structural function in plants and therefore may play a role in determining biomass reactivity to pretreatment. It has been proposed that substitutions along xylan chains are not random and, based upon studies of pericarp xylan, are organized in domains that have specific structural functions. Analysis of intact xylan is problematic because of its chain length (> degree of polymerization (d.p.) 100) and heterogeneous side groups. Traditionally, enzymatic end-point products have been characterized due to the limited products generated. Analysis of resultant arabino-xylo-oligosaccharides by mass spectrometry is complicated by the isobaric pentose sugars that primarily compose xylan. In this report, the variation in pentose ring structures was exploited for selective oxidation of the arabinofuranose primary alcohols followed by acid depolymerization to provide oligosaccharides with modified arabinose branches intact. Switchgrass samples were analyzed by hydrophilic interaction chromatography (HILIC)-liquid chromatography (LC)-mass spectrometry/mass spectrometry (MSMS) and off-line nanospray MS to demonstrate the utility of this chemistry for determination of primary hydroxyl groups on oligosaccharide structures, with potential applications for determining the sequence of arabino-xylo-oligosaccharides present in plant cell wall material. Published in 2011 by John Wiley & Sons, Ltd.