Increased antioxidant activity and improved structural characterization of sulfuric acid-treated stepwise degraded polysaccharides from Pholiota nameko PN-01

The aim of this study was to investigate sulfuric acid degradation of the Pholiota nameko polysaccharide (ALPS-1). Three stepwise degraded polysaccharides (AIPS-2, AIPS-3, and AIPS-4) were obtained by sequentially increasing the strength of sulfuric acid treatment. Structural characterization showed that sulfuric acid treatment significantly decreased molecular weight, increased the content of uronic add and changed the molar ratio of monosaccharide composition, while the major functional groups and the triple helical conformation of polysaccharides did not change significantly. in vitro experiments proved that the antioxidation ability of the stepwise degraded polysaccharides gradually increased (ALPS-I < AIPS-2 < AIPS-3 < AIPS-4). An oxidative stress zebrafish model was established, which demonstrated that the ability of AIPS-3 and AIPS-4 to scavenge free radicals in zebrafish was significantly improved compared to ALPS-1. In conclusion, sulfuric acid treatment is an effective method for improving the antioxidant activity of polysaccharides, and increased antioxidant activity was closely related to the changes in their structural characteristics. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study aimed to investigate the sulfuric acid degradation of Pholiota nameko polysaccharide and found that the treatment significantly altered the structural characteristics and enhanced the antioxidant activity of the polysaccharides. In vitro and in vivo experiments demonstrated that the stepwise degraded polysaccharides showed improved antioxidant capacity, with the ability to scavenge free radicals in zebrafish significantly enhanced.