Structural Characterization and Bioactivity Analysis of Ultrasound-Assisted Polysaccharides From Codonopsis pilosula: Insights Into Antioxidant and Hypoglycemic Potentials

Abstract

Codonopsis pilosula is a genuine medicinal material and edible plant. However, the structure and activity of its polysaccharides have been infrequently studied. In this study, crude polysaccharides were extracted using ultrasound-assisted extraction (UAE), six distinct polysaccharides (UA-Cpps) were obtained from the crude polysaccharides by separation with a DEAE-cellulose column and purification using an S-100 chromatography column. This study examined the physicochemical properties and structure of six UA-Cpps using high-resolution spectroscopy and microscopic imaging technology. Scanning electron microscopy demonstrated that UA-Cpps1 and UA-Cpps6 had similar morphologies, characterized by smooth, dense surfaces with uneven textures composed of small particles. Methylation analysis indicated that the six UA-CPPs were primarily linked by 1 → 4 and 1 → 6 glycosidic bonds. Notably, the 1 → 4 glycosidic bond type enhances the antioxidant properties of UA-Cpps, with both UA-Cpps3 and UA-Cpps5 exhibiting strong antioxidant activity that inhibits α-amylase and α-glucosidase. Molecular docking studies demonstrated that UA-CPPs and two enzymes were capable of forming stable structures through multiple hydrogen bonds. This study offers scientific evidence supporting the application of C. pilosula in health promotion and the management of emerging health issues.

Keywords: C. pilosula polysaccharide; blood glucose‐lowering activity; molecular docking; oxidative stress‐inhibiting activity; structure characterization.