Preparative Isolation of 5 Antioxidant Constituents from the Medicinal Mushroom Phellinus baumii (Agaricomycetes) by High-Speed Countercurrent Chromatography and Preparative High-Performance Liquid Chromatography.

Four extract fractions from the fruiting bodies of Phellinus baumii were acquired. Preliminary investigation of radical scavenging ability showed that the ethyl acetate extract exhibited the strongest antioxidant activity. To gain insight into the antioxidant mechanism, 5 antioxidant constituents were prepared from the ethyl acetate extract using high-speed countercurrent chromatography with a solvent system consisting of n-hexane, ethyl acetate, methanol, and water (0.8:3:1.5:2.5, v/v/v/v), and preparative high-performance liquid chromatography. Electrospray ionization mass spectrometry and nuclear magnetic resonance spectra were used to analyze the structures of these compounds and revealed that they were caffeic acid (compound 1), inoscavin A (compound 2), 3,4-dihydroxy benzaldehyde (compound 3), coumarin (compound 4), and naringenin (compound 5). Compound 2 showed strong antioxidant activity, and compounds 1, 3, and 5 showed moderate antioxidant activity. Thus, a more clearly and usefully scientific background is provided herein for the development of relative functional foods or biomedical products using Ph. baumii as the raw material.