Two Novel Polysaccharides From Clitocybe squamulosa: Their Isolation, Structures, and Bioactivities

Dongdong Guo; Jiayu Lei; Lijing Xu; Yanfen Cheng; Cuiping Feng; Junlong Meng; Mingchang Chang; Xueran Geng

doi:10.3389/fnut.2022.934769

Two Novel Polysaccharides From Clitocybe squamulosa: Their Isolation, Structures, and Bioactivities

Front Nutr. 2022 Jun 30:9:934769. doi: 10.3389/fnut.2022.934769. eCollection 2022.

Authors

Dongdong Guo¹, Jiayu Lei¹, Lijing Xu^{1

2}, Yanfen Cheng^{1

2}, Cuiping Feng^{1

2}, Junlong Meng^{1

3}, Mingchang Chang^{1

3}, Xueran Geng^{1

2}

Affiliations

¹ College of Food Science and Engineering, Shanxi Agricultural University, Taigu, China.
² Shanxi Key Laboratory of Edible Fungi for Loess Plateau, Taigu, China.
³ Shanxi Engineering Research Center of Edible Fungi, Taigu, China.

Abstract

The crude polysaccharides from the fruiting bodies of Clitocybe squamulosa (CSFP) were isolated by hot-water extraction. Two novel polysaccharides, CSFP1-β and CSFP2-α, were further purified by DEAE-52 anion exchange and Sephacryl S-400 gel filtration chromatography, and the purities reached 98.44 and 97.83%, respectively. The structural characteristics and bioactivities of CSFP, CSFP1-β, and CSFP2-α were identified by the combination of chemical and instrumental analysis. Results showed that CSFP was formed by the aggregation of honeycomb spherical materials; CSFP1-β and CSFP2-α were interwoven by reticular and fibrous structures, respectively. Purified components of both CSFP1-β and CSFP2-α showed typical infrared absorption peaks of polysaccharides, and contents of nucleic acid and protein decreased significantly. Simultaneously, CSFP with a molecular weight (Mw) of 1.948 × 10⁴ Da were composed mainly of glucose, mannose, galactose, and rhamnose. CSFP1-β was composed mainly of glucose, galactose, and mannose, while CSFP2-α was composed of glucose, and both their Mw distributions were uneven. Compared with CSFP, the antioxidant activities of CSFP1-β and CSFP2-α were significantly improved (p < 0.05), and they both showed good abilities to bind free cholesterol and bile acid salts in vitro. The binding abilities of the two compounds were found to be 68.62 and 64.43%, and 46.66 and 45.05 mg/g, respectively. CSFP, CSFP1-β, and CSFP2-α had good bacteriostatic effects with a linear increasing relationship to increasing concentration. In addition, CSFP promoted the growth of RAW264.7 cells and has potential immunomodulatory, anti-inflammatory, and anti-tumor activities.

Keywords: Clitocybe squamulosa polysaccharides; bioactivity; physicochemical properties; purification; structural characterization.