Purification, Characterization, and Antioxidant Activities of Polysaccharides From Leaves of <i>Hemerocallis citrina</i> Baroni

The leaves of Hemerocallis citrina Baroni (H. citrina Baroni) are a promising source of bioactive polysaccharides (HCLP). However, the presence of abundant pigments in crude HCLP complicates subsequent purification and analysis, making an effective decolorization step essential. A model of decolorization conditions of HCLP was established using single factor and response surface methodology (RSM), and the optimal decolorization conditions were obtained. Subsequently, the HCLP-0.1 was successfully isolated via DEAE-52 cellulose column. Structural characterization revealed that HCLP-0.1 has a molecular weight (M_w) of 8317.64 Da, composed of Man, GlcN, Rha, GlcA, GalA, Glc, Gal, Xyl, and Ara. Furthermore, HCLP-0.1 was characterized by α- and β-pyranose configurations, crystallinity, and an irregular triple-helical structure. Thermal analysis demonstrated excellent thermal stability. Antioxidant assays revealed that HCLP-0.1 possesses significant concentration-dependent (0.1-2.0 mg/mL) scavenging capacity against ABTS, hydroxyl, and DPPH radicals. These results support the potential of HCLP as a natural antioxidant, providing a solid basis for its future application in functional foods or pharmaceuticals.