AVS 66th International Symposium & Exhibition
    Biomaterial Interfaces Division Monday Sessions
       Session BI+AS-MoA

Paper BI+AS-MoA4
ToF-SIMS Analysis of the Distribution of p-Hydroxybenzoate in Wood

Monday, October 21, 2019, 2:40 pm, Room A120-121

Session: Cutting Edge Bio: Bio-Nano, Bio-Energy, 3D Bio
Presenter: Robyn E. Goacher, Niagara University
Authors: R.E. Goacher, Niagara University
Y. Mottiar, University of British Columbia, Canada
Correspondent: Click to Email
The progress towards a green bio-based economy depends in part on our ability to chemically modify lignocellulosic plant matter. Possible targets for such chemical modifications include ester-linked pendant groups that occur on lignin in some plant species. The lignin in poplar and willow is known to contain 1-10% of p-hydroxybenzoate (-pHB) moieties, although little is known about the function of these -pHB groups. To understand the function of -pHB, it is important to understand the distribution of -pHB among different cell types. Previous work with ultraviolet microscopy suggests that -pHB is present only in fibers and not in vessels. The goal of this work is to provide a more specific analysis of the spatial distribution of -pHB in wood by using surface-sensitive chemical imaging. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to image cross-sections of mature Lombardy poplar, juvenile (greenhouse-grown) Lombardy poplar and mature DUKE-5 willow. Lombardy poplar is known to contain higher levels of -pHB than the DUKE-5 willow. Samples were analyzed prior to and after solvent extraction to remove spectral interferences from small molecule extractives, which have similar chemical composition to -pHB and lignin. A milk alkaline hydrolysis was also performed to cleave ester-linked -pHB from lignin in order to confirm identification of certain peaks within the mass spectra as characteristic of -pHB. Multivariate statistical analysis was used to aid in the data interpretation. The process of identifying peaks that arise from -pHB will be discussed, and chemical images of the localization of -pHB will be presented. This data contributes to our understanding of how -pHB is distributed in wood. These insights may shed light on the role of ester-linked moieties in lignin and will hopefully advance the use of -pHB as a biotech target.