Studies on structure and antioxidant properties of a heteroglycan isolated from wild edible mushroom Lentinus sajor-caju

• Published in: International journal of biological macromolecules Vol. 107; no. Pt A; pp. 322 - 331
• Main Authors: Pattanayak, Manabendra, Maity, Prasenjit, Samanta, Surajit, Sen, Ipsita K., Manna, Dilip K., Nandi, Ashis K., Ghosh, Sandipta, Acharya, Krishnendu, Islam, Syed S.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2018
• Subjects: Antioxidant activities; Heteroglycan; Lentinus sajor-caju; Heteroglycan; Lentinus sajor-caju; Antioxidant activities
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2017.08.163

•A heteroglycan was isolated from an edible wild mushroom Lentinus sajor-caju.•The molecule was composed of d-glucose, d-galactose, d-mannose, and l-fucose.•The structure was characterized by chemical and 1D/2D NMR studies.•The heteroglycan exhibited moderate antioxidant activities. A water-soluble heteroglycan (PS-I) isolated from the aqueous extract of a wild edible mushroom Lentinus sajor-caju showed average molecular weight ∼1.79×105Da. The structure of the polysaccharide was determined using chemical and 1D/2D NMR experiments. Acid hydrolysis indicated the presence of d-glucose, d-galactose, d-mannose, and l-fucose in a molar ratio of nearly 4:4:1:1 respectively. The presence of terminal Fucp, terminal Galp, (1→3)-Glcp, (1→6)-Galp, (1→6)-Glcp, (1→4,6)-Galp, and (1→2,4)-Manp moieties were established from methylation analysis. The chemical and NMR analyses indicated that the PS-I was a heteroglycan composed of a repeating unit with backbone chain of three (1→6)-α-d-galactopyranosyl residues, two (1→6)-β-d-glucopyranosyl residues, one (1→4)-α-d-mannopyranosyl residue, and two (1→3)-β-d-glucopyranosyl residues where one (1→6)-α-d-galactopyranosyl residue was branched at O-4 position with terminal α-l-fucopyranosyl residue and (1→4)-α-d-mannopyranosyl residue was branched at O-2 position with terminal α-d-galactopyranosyl residue and the structure was proposed as; The PS-I is a moderate antioxidant compound which showed DPPH radical scavenging activity, hydroxyl radical scavenging activity, ABTS radical scavenging property, reducing power, and ferrous ion chelating ability. [Display omitted]