Preparation, structural identification, and in vitro activity study of polysaccharides and derivatives from Polygonatum hunanense

Polysaccharides are one of the main active components of Polygonatum hunanense (PHP). This study extracted polysaccharides from the roots of PHP using water extraction and ethanol precipitation methods. Additionally, PHP was isolated and purified through various techniques, particularly through Diethylaminoethyl-52 (DEAE-52) cellulose and Sephadex G-100 chromatography columns. Structural analysis revealed that PHP is composed of 94.9 % fructose and 5.1 % glucose, with a molecular weight of 6.01 kDa. Moreover, the main chain of PHP residues linkage was found to be β-D-Fruf-(2 → 6)-D-Glcp-(1 → 2)-β-D-Fruf-(6,1 → 2)-β-D-Fruf-(1 → 2)-β-D-Fruf. Branch chain analysis revealed the presence of →2)-β-D-Fruf-(1, 6 → 2)-β-D-Fruf-(1 → 2)-β-D-Fruf. Subsequently, PHP was chemically modified, yielding acetylated polysaccharides (Ac-PHP) and sulfated polysaccharides (Su-PHP). The identification results from Fourier-transform infrared spectroscopy and ¹³C nuclear magnetic resonance spectra indicated the successful derivatization of the polysaccharides. In vitro bioactivity experiments demonstrated that PHP, Ac-PHP, and Su-PHP can induce cell apoptosis and affect the cell cycle, leading to cytotoxicity toward tumor cells. Compared to PHP, Ac-PHP and Su-PHP exhibited enhanced effects in all groups. These results suggest that PHP might be a promising candidate and supplement for cancer treatment, while the acetylated and sulfated PHP polysaccharides may enhance their antitumor activity by altering their structures.