Depolymerization of holocellulose from Chinese herb residues by the mixture of lignin-derived deep eutectic solvent with water

Xiaoyan Chen; Qinghua Zhang; Qiang Yu; Long Chen; Yongming Sun; Zhongming Wang; Zhenhong Yuan

doi:10.1016/j.carbpol.2020.116793

Depolymerization of holocellulose from Chinese herb residues by the mixture of lignin-derived deep eutectic solvent with water

Carbohydr Polym. 2020 Nov 15:248:116793. doi: 10.1016/j.carbpol.2020.116793. Epub 2020 Jul 22.

Authors

Xiaoyan Chen¹, Qinghua Zhang², Qiang Yu³, Long Chen⁴, Yongming Sun⁴, Zhongming Wang⁴, Zhenhong Yuan⁴

Affiliations

¹ Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS Key Laboratory of Renewable Energy, Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou, 510640, China; University of Chinese Academy of Sciences, Beijing, 100039, China.
² College of Bioscience and Biotechnology, Jiangxi Agricultural University, Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, Nanchang, 330045, China.
³ Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS Key Laboratory of Renewable Energy, Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou, 510640, China; Dalian National Laboratory For Clean Energy, Dalian, 116023, China. Electronic address: yuqiang@ms.giec.ac.cn.
⁴ Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS Key Laboratory of Renewable Energy, Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou, 510640, China.

PMID: 32919533
DOI: 10.1016/j.carbpol.2020.116793

Abstract

The depolymerization of biomass carbohydrate polymers usually happened in homogeneous medium, just a few in heterogeneous solution. Herein, holocellulose from two Chinese herb residues Cortex albiziae (HRCA) and Heteropogon contortus (HRHC) was prepared and characterized. Deep eutectic solvent (DES) of choline chloride/p-coumaric acid collaborating with water was employed for the dissociation of those two holocelluloses and selectively dissolved hemicellulose into xylose with maximal yields of 81.50 % and 72.47 %, respectively. Most cellulose remained as the polymer state with a maximum solubility of 9.38 %. The synergistic action of DES and water was investigated to unveil the depolymerization mechanism and the roles of each component in depolymerizing procedure. It was water that released hemicellulose polymers and dissolved polymers to soluble short oligosaccharides, and DES rapidly cleaved the latter to xylose. Contrarily, DES broke cellulose to only soluble cello-oligosaccharides, but water exhibited the ability to hydrolyze cellulose to glucose.

Keywords: Chinese herb residues; DES/water synergistic action; Deep eutectic solvent; Dissolving mechanism; Holocellulose depolymerization.