Pleurotus citrinopileatus was successfully cultivated and commercially available in Korea. The antioxidant, xanthine oxidase, tyrosinase inhibitory activities and polyphenol contents of fruiting bodies of Pleurotus citrinopileatus extracted with acetone, hot water and methanol (hereinafter referred to Fr. Ace, Fr. HW and Fr. MeOH). The antioxidant activities on β-carotene-linoleic acid in the Fr. Ace, Fr. HW and Fr. MeOH were 96.12%, 94.21% and 96.52%, respectively at the concentration of 20 mg/ml. Xanthine oxidase inhibition activity in the Fr. Ace, Fr. HW and Fr. MeOH were 30.12%, 35.42% and 29.02%, respectively at the concentration of 5 mg/ml. Tyrosinase inhibition activity in the Fr. Ace, Fr. HW and Fr. MeOH were 58.78%, 49.25% and 63.29%, respectively at the concentration of 1.0 mg/ml. Total polyphenol contents in the Fr. Ace, Fr. HW and Fr. MeOH were 18.99 mgGAEs/g, 16.73 mgGAEs/g and 18.66 mgGAEs/g. These experimental results suggested that fruiting bodies of P. citrinopileatus contained good physio-chemical substances for promoting human health.

The antioxidant, xanthine oxidase, tyrosinase inhibitory activities and polyphenol contents of the fruiting bodies of Pleurotus cornucopae extracted with acetone, hot water and methanol (hereinafter referred to Fr. Ace, Fr. HW and Fr. MeOH). The antioxidant activities in the Fr. Ace, Fr. HW and Fr. MeOH were 93.23%, 89.55% and 92.58%, respectively at the concentration of 2.0 mg/ml. Xanthine oxidase inhibition activity in the Fr. Ace, Fr. HW and Fr. MeOH were 45.84%, 46.50% and 45.60%, respectively at the concentration of 5 mg/ml. Tyrosinase inhibition activity in the Fr. Ace, Fr. HW and Fr. MeOH were 52.11%, 50.12% and 55.81%, respectively at the concentration of 1.0 mg/ml. Total polyphenol contents in the Fr. Ace, Fr. HW and Fr. MeOH were 18.99 mgGAEs/ g, 16.73 mgGAEs/g and 18.66 mgGAEs/g. These experimental results suggested that fruiting bodies of P. cornucopae contained good physio-chemical substances for promoting human health.

The current investigation was undertaken to evaluate the antioxidant activities, tyrosinase inhibitory effects on the fruiting bodies of P. ostreatus extracted with acetone, methanol and hot water. The antioxidant activities were performed on β-carotene-linoleic acid, reducing power, 1,1-diphenyl-2-picrylhydrazyl free radical scavenging, and ferrous chelating abilities. In addition to this, phenolic acid and flavonoids contents were also analyzed. Methanolic extract of P. ostreatus showed the strongest β-carotene-linoleic acid inhibition as compare to others exracts. At 8 mg/ml, acetonic extract showed a high reducing power of 1.54. The scavenging effects on 1,1-diphenyl-2-picrylhydrazyl radicals, acetonic extract was effective than other extracts. The strongest chelating effect (85.66%) was obtained from the acetonic extract at 1.0 mg/ml concentration. Antioxidant activities of the extracts from the fruiting bodies of P. ostreatus were increased with the increasing concentration. After application of reverse phase high performance liquid chromatography, coupled to a diode array detector and electrospray ionisation mass spectra, six phenolic compounds namely, gallic acid, protocatechuic acid, naringenin, hesperetin, formononetin and biochanin were identified from acetonic extract. Tyrosinase inhibition of acetonic, methanolic, and hot water extracts of P. ostreatus were increased with the increasing of concentration. Results revealed that methanolic extract showed good, while acetonic and hot water extracts showed moderate activities of the tyrosinase inhibition at the concentration tested. This study suggests that fruiting bodies of P. ostreatus can potentially be used as a readily accessible source of natural antioxidants.