Carboxymethylation of polysaccharide isolated from Alkaline Peroxide Mechanical Pulping (APMP) waste liquor and its bioactivity

In recent years, the biological activity of polysaccharides and their derivatives has been widely studied. However, in addition to the natural polysaccharides directly extracted from plants and animals, there are rich polysaccharides in the pulping waste liquor that have not been fully utilized. The extracted polysaccharide from eucalyptus Alkaline Peroxide Mechanical Pulping (APMP) waste liquor was used as a raw material. For the production of carboxymethyl polysaccharide, the effects of temperature (T), the amount of alkali (NaOH) and the amount of etherifying agent (CICH2COOH) on the degree of substitution (DS) were investigated, the optimal preparation conditions are: reaction time 2 h. temperature 75 degrees C, and the molar ratio of polysaccharide, NaOH and CICH2COOH is 1:1:2. the highest DS is 1.47; FT-IR, NMR and GPC were used to characterize the structure and Molecular weight, the results show that the polysaccharide of APMP waste liquor is rich in xylan, and it was proved that the carboxymethyl substitution was successful and the positions of the substituent group were determined. The characterization and biological activity research of xylan polysaccharide (XP) and carboxymethyl xylan polysaccharide (CMXP), such as antioxidation, moisture absorption/retention, bacteriostatic action and cytotoxicity were discussed. CMXP shows better effects compared with XP. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, polysaccharides extracted from eucalyptus pulping waste liquor were used to produce carboxymethyl polysaccharide. The study investigated the effects of preparation conditions on the degree of substitution and characterized the structure and molecular weight of the polysaccharide. It was found that carboxymethyl substitution was successful and the positions of the substituent group were determined. The carboxymethyl xylan polysaccharide showed better biological activity compared to xylan polysaccharide.