Structure and antinociceptive effects of β-d-glucans from Cookeina tricholoma

• (1 → 3),(1 → 6) β-d-Glucans from the mushroom-forming ascomycete Cookeina tricholoma.
• (1 → 3)-Linked β-d-Glcp O-6 substituted by (1 → 6)-linked β-d-Glcp and β-d-Glcp.
• The antinociceptive effect is mostly related to MW than to branching degree.
• β-d-Glucans with similar MW showed significant inhibition of neurogenic pain.

Structurally different water-insoluble (1 → 3),(1 → 6) β-d-glucans were isolated from aqueous and alkaline extracts of the mushroom-forming ascomycete Cookeina tricholoma, a wild edible mushroom found in Brazilian Amazon forest. The structures showed different substitution patterns, which may influence their extractability and consequently their conformation in solution, and different MW (4.3 × 105 Da, 3.7 × 105 Da and 8.2 × 105 Da, for ICW-Ct, IHW-Ct and IK2-Ct, respectively). The main-chains are composed of (1 → 3)-linked β-d-Glcp units O-6 substituted by side chains with different lengths of (1 → 6)-linked β-d-Glcp units (ICW-Ct and IHW-Ct) or by a combination of (1 → 6)-linked β-d-Glcp units and single units of β-d-Glcp (IK2-Ct).β-d-glucans with similar MW and showing only (1 → 6)-linked β-d-Glcp units as side chains (ICW-Ct and IHW-Ct) showed significant inhibition of neurogenic pain, 69 ± 11 and 57 ± 11% at the dose of 10 mg kg−1, respectively, in the model of nociception induced by intraplantar injection of formalin.