Determination of antioxidant activity and antioxidant compounds in wild edible mushrooms

The methanolic extracts of dried Agaricus bisporus, Polyporus squamosus, Pleurotus ostreatus, Lepista nuda, Russula delica, Boletus badius, and Verpa conica were analyzed for antioxidant activity in different systems including reducing power, free radical scavenging, superoxide anion radical scavenging, total antioxidant activity, and metal chelating activities. Those various antioxidant activities were compared to standard antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and alpha-tocopherol. The percentage inhibition methanolic extracts of dried Russida delica, Boletus badius, Agaricus bisporus, Polyporus squamosus, Pleurotus ostreatus, Lepista nuda and Verpa conica at 100 mu g/mL concentrations on peroxidation in linoleic acid system were 99.7%, 99.2%, 98.8%, 98.4%, 98.3%, 97.9% and 97.7%, respectively, and greater than those 400 mu g/mL of alpha-tocopherol, BHA and BHT (77%, 85%, and 97%). Among methanolic extracts from seven wild edible mushrooms, the reducing power of Russida delica and Verpa conica were excellent, and were 1.32 and 1.22 at 200 mu g/mL, respectively. Methanolic extract from Verpa conica, Boletus badius and Russula delica proved to be better at scavenging O-2(-center dot) than other mushroom species. The scavenging effects of methanolic extracts from mushroom species and standards on the DPPH center dot radical decreased in the order of BHA > alpha-tocopherol > Lcpista nuda > Russula delica > Polyporus squamosus > Pleurotus ostreatus > Agaricus bisporus > Verpa conica > Boletus badius and were, at the concentration of 180 mu g/mL, 97.4, 95.4, 91.3, 86.1, 82.8, 81.3, 77.5, 75.7 and 68.7, respectively. The metal scavenging effect of extract of the mushroom species and standards decreased in the order of Verpa conica > Lepista nuda > Russida delica > Boletus badius > Polyporus squamosus > BHT > Pleurotus ostreatus > Agaricus bisporus > BHA > alpha-tocopherol. On the other hand, total phenolic compounds, alpha-tocopherol, and beta-carotene were determined in the methanolic extracts of dried Agaricus bisporus, Polyporus squamosus, Pleurotus ostreatus, Lepista nuda, Russula delica, Boletus badius, and Verpa conica. (c) 2006 Elsevier Inc. All rights reserved.