Structural characterisation of acid- and alkali-soluble polysaccharides in the fruiting body of Dictyophora indusiata and their immunomodulatory activities

Abstract The acid- and alkali-soluble polysaccharides (DIPs I and II) were extracted from the fruiting body of Dictyophora indusiata in this work. DIP I comprised of Glc (glucose), Fru (fructose) and Man (mannose), whereas DIP II was of Glc and Fru. Glc was the dominant monosaccharide in both DIPs with relatively molar percentage of >60%, which constructed the backbone of polysaccharide chain. The analysis of the glycosidic linkages indicated that Glc occurred as Glc 1 → 6 in DIP II. The immunological assays showed that both DIPs I and II had a noticeable effect on the hemolysis antibody level in the tested dosage range. However, DIP I could improve the weight of thymus organ and phagocytosis of monocyte. DIP II could restore delayed-type hypersensitivity reaction to dinitrofluorobenzene (DNFB), improving the activity of natural killer cells and the proliferation of splenocytes at high dose.