Structural Characterization and Immune Regulation of a New Heteropolysaccharide from Catathelasma imperiale (Fr.) Sing

Background: Polysaccharide has played the part of great role in pharmacology and physiology. Materials and Methods: In this study, the polysaccharides (CIS‑A) from Catathelasma imperiale (Fr.) Sing, were isolated and purified by hot water extraction technology and column chromatography, respectively. Chemical methods, infrared spectrum, high‑performance gel‑permeation chromatography, high‑performance liquid chromatography, gas chromatography–mass spectrometry, 1H nuclear magnetic resonance spectroscopy (NMR), 13C NMR, and two‑dimensional NMR were used to characterize the polysaccharides of CIS‑A. The anticancer and immunomodulatory ability of the polysaccharides (CIS‑A) from the fruiting body of C. imperiale (Fr.) Sing was also investigated. Results: The structural feature analysis showed the polysaccharide (CIS‑A) which had a molecular weight of 50486 Da was mainly composed of α‑D‑glucose pyranose (α‑D‑Glcp) and β‑L‑fucose pyranose (β‑L‑Fucp). It had a backbone of three 1, 3‑linked α‑D‑Glcp. There is a branch at the C2 of the polysaccharide backbone. The branches were mainly composed of two 2, 3‑linked β‑L‑Fucp residue. Antitumor activity results showed that CIS‑A could inhibit the growth of S180 tumor and promote the apoptosis of L929 cells. Immunoregulatory activity results showed that CIS‑A could promote the proliferation of T‑cells and promote B‑cells by affecting G0/G1 phase, S phase, and G2/M phase. It also could promote the proliferation and phagocytosis of macrophages and induce cytokine release. Conclusion: Polysaccharide CIS‑A can be used as a candidate drug for antitumor and immunomodulator.