Styrylpyrones from the medicinal fungus Phellinus baumii and their antioxidant properties

During the search for natural antioxidants from basidiomycetes, a new styrylpyrone, baumin (1), was isolated from the cultivated medicinal fungus Phellinus baumii, together with known compounds, davallialactone (2), hispidin (3), hypholomine B (4), interfungin A (5), inoscavin A (6), and phelligridin D (7), which were previously isolated from the medicinal fungi Phellinus ignarius, Phellinus linteus, and Inonotus xeranticus. Their structures were elucidated by extensive spectroscopic methods. These compounds exhibited antioxidant activity through Fenton reaction inhibition via iron chelation and free radical scavenging.