Structural characterization of an immunoenhancing glucan isolated from a mushroom Macrolepiota dolichaula

• Published in: International journal of biological macromolecules Vol. 61; pp. 89 - 96
• Main Authors: Samanta, Surajit, Nandi, Ashis K., Sen, Ipsita K., Maji, Praloy K., Devi, K. Sanjana P., Maiti, Tapas K., Islam, Syed S.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-10-2013
• Subjects: Agaricales - chemistry; Animals; Branched glucan; cell culture; Cell Line; culture media; Dose-Response Relationship, Drug; fruit extracts; fruiting bodies; glucans; Glucans - chemistry; Glucans - isolation & purification; Glucans - pharmacology; hydrolysis; Immunoactivation; Immunologic Factors - chemistry; Immunologic Factors - isolation & purification; Immunologic Factors - pharmacology; Macrolepiota; Macrolepiota dolichaula; macrophage activation; Macrophage Activation - drug effects; Macrophage Activation - immunology; Macrophages - drug effects; Macrophages - immunology; methylation; Mice; molecular weight; mushrooms; NMR studies; nuclear magnetic resonance spectroscopy; Nuclear Magnetic Resonance, Biomolecular; thymocytes; Branched glucan; Immunoactivation; Macrolepiota dolichaula; NMR studies
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2013.06.010

•A soluble branched β-d-glucan (PS-I) was isolated from the mushroom M. dolichaula.•Structure of the PS-I was determined by chemical as well as 1D/2D NMR studies.•The PS-I showed in vitro macrophage activation.•It also showed splenocyte and thymocyte activation in mouse cell culture medium.
A water soluble branched glucan (PS-I) was isolated from aqueous extract of the fruit bodies of an edible mushroom Macrolepiota dolichaula, having average molecular weight ∼2.02×105Da. The structure of this PS-I was determined using total hydrolysis, methylation analysis, Smith degradation, partial hydrolysis, and 1D/2D NMR experiments. Total hydrolysis and methylation analysis results showed the presence of (1→3, 6)-, (1→6)-, (1→4)-, (1→3)-linked and terminal β-d-glucopyranosyl residues in a relative proportion of nearly 1:2:1:1:1. All the chemical and NMR results indicated that the PS-I was a branched glucan, and the repeating unit of this glucan consisted of a backbone chain of three (1→6)-linked-β-d-glucopyranosyl residues where one of the backbone residues is branched at O-3 with (1→3)- moiety which is further attached to another (1→4)- residue and terminated with a non-reducing β-d-glucopyranosyl residue. The PS-I exhibited in vitro macrophage activation in RAW 264.7 cell line as well as splenocyte and thymocyte activation in mouse cell culture medium.