Antioxidant Activities In Vitro of Ethanol Extract and Fractions from Mushroom,Lenzites Betulina

The antioxidant potential of different fractions of Lenzites betulina was investigated. Fraction 2 showed the highest antioxidant activity in the 2, 2‐diphenyl‐1‐picrylhydrazyl (DPPH) and hydroxyl (OH) radical‐scavenging assays. Three natural p‐terphenyls were identified in this fraction. The structure of a new natural compound was established as 2‐phenyl‐1H‐2‐benzopyran]4,3‐e]p]benzoquinone in addition to two other compounds, 2,5‐diphenyl‐3,6‐dimethoxy‐p‐benzoquinone and 2‐phenyl‐3‐methoxy‐1H‐2‐benzopyran]4,3‐e]p]benzoquinone that have been previously reported in L. betulina. The antioxidant activities of these p‐terphenyls were evaluated by DPPH and OH radical‐scavenging assays. 2‐phenyl‐3‐methoxy‐1H‐2‐benzopyran]4,3‐e]p]benzoquinone was the most active in the OH radical‐scavenging test (IC ₅₀ = 37.69 μg/mL) and showed little inhibition in the DPPH assay. The chemical components of L. betulina therefore have some antioxidant capacities, and this species could be used as a potential source of new natural antioxidants.