A heteroglycan from the mycelia of Pleurotus ostreatus: structure determination and study of antioxidant properties.

Carbohydrate research

PubMedID: 23314300

Patra S, Patra P, Maity KK, Mandal S, Bhunia SK, Dey B, Devi KS, Khatua S, Acharya K, Maiti TK, Islam SS. A heteroglycan from the mycelia of Pleurotus ostreatus: structure determination and study of antioxidant properties. Carbohydr Res. 2013;36816-21.
A heteroglycan (PS) isolated from the mycelia of Pleurotus ostreatus was found to consist of l-fucose, d-mannose, and d-glucose in a molar ratio of nearly 1:2:3. On the basis of acid hydrolysis, methylation analysis, periodate oxidation, and NMR studies (1H, 13C, TOCSY, DQF-COSY, NOESY, ROESY, HSQC, HMBC, and DEPT), the structure of the repeating unit of the PS was determined. The repeating unit had a branched backbone composed of (1?6)-linked a and ßd-glucose and (1?2)-linked a-l-fucose. Branching occurred at C-4 position of (1?6)-linked a-d-glucopyranosyl residue with terminal ß-d-mannose and C-3 position of (1?6)-linked ß-d-glucopyranosyl residue with (1?6)-a-d-mannopyranosyl moiety terminated by a-d-glucose. The structure of the repeating unit of the PS was proposed as: [formula: see text]. The antioxidant properties of the PS were studied. The scavenging activity of hydroxyl free radicals whose EC50 value of PS at 943 µg/mL was determined. Further, EC50 value of the PS at 53 µg/mL was observed for scavenging activity of superoxide free radicals. Chelating effects (54.82%) of ferrous ions were observed at 1mg/mL of the PS.