Structural characterization and immunomodulating activities of polysaccharides from a newly collected wild Morchella sextelata

Abstract

A purified polysaccharide was acquired from a newly collected wild Morchella. The strain identification initially showed that the strain was Morchella sextelata. This study aimed to investigate the structural features and immunomodulating activities of the polysaccharide. Polysaccharide extracted from mycelia was purified by DEAE-cellulose chromatography and Sephadex G-25 size-exclusion chromatography in sequence. The main fraction of polysaccharide (MSP-II) was obtained during purification process. High Performance Liquid Chromatography (HPLC) analysis revealed that MSP-II was composed of Glc, Ara, Gal, Man, Rha, Fuc, GalUA and GluUA in ratio of 34.95:8.7:9.55:4.55:5.0:1.45:12.7:7.65. The structure of MSP-II was furtherly analyzed by FT-IR spectrum and ¹H and ¹³C NMR spectroscopy, the results showed that MSP contained β-glycosidic bonds as well as α-glycosidic linkages. In vitro tests proved that MSP-II could not only promote the proliferation and phagocytosis of RAW264.7 cells, but also induce the section of nitric oxide (NO) of macrophages. Consequently, the polysaccharide has a potent immunomodulatory activity by stimulating macrophages and can be considered as a novel potential immunopotentiator in medical and food industries.

Keywords: Immunomodulatory; Morchella sextelata; Polysaccharides; Purification.