Wei Gao, Kundian Che, Baogang Zhou, Ran Liu, Zhanjun Chen, Jialin Yang, Haoyuan Luo, Chengfei Huang, Jiayu Wang, Ke Feng, Sarengaowa, Wenzhong Hu
This study isolated and purified two polysaccharide fractions, PTP-1 and PTP-2, from Phragmites communis Trin root via cellulase-assisted ultrasonication and DEAE chromatography, with purities of 90.56% and 91.35%, respectively. Structural characterization revealed that PTP-2 possessed a higher uronic acid content (9.45%) compared to PTP-1 (3.0%), along with a hyperbranched architecture and superior thermal stability. High-performance gel permeation chromatography (HPGPC) indicated that PTP-1 and PTP-2 had weight-average molecular weights of 55.8 kDa and 59.6 kDa, respectively, reflecting distinct structural features. In vitro assays demonstrated that PTP-2 exhibited potent α-glucosidase inhibition (IC 50 = 0.679 mg/mL) and significantly enhanced glucose uptake and glycogen synthesis in insulin-resistant HepG2 cells, attributable to its uronic acid-enriched structure. These findings highlight PTP-2 as a promising multi-target agent for diabetes management, underscoring the structure–activity relationship of plant polysaccharides.