Two sarcoviolins with antioxidative and α-glucosidase inhibitory activity from the edible mushroom Sarcodon leucopus collected in Tibet.

Edible mushrooms are known as an important source of natural antioxidants. The ethyl acetate extract of the edible mushroom Sarcodon leucopus (Zangzi mushroom) possesses strong antioxidative activity. Bioactivity-guided isolation afforded 10 compounds from its fruiting bodies, including two new sarcoviolins, sarcoviolin beta (1) and episarcoviolin beta (2), and one new p-terphenyl derivative (3) along with seven known compounds. The structures of the new compounds were elucidated by spectroscopic methods and comparison with the known compounds. Compounds 1-10 were found to have antioxidant effects in the DPPH scavenging assay, the total antioxidant capacity assay, the reducing power assay, and the lipid peroxidation assay. Further study indicated that they could protect DNA strands from free radical-induced cleavage at 200 mu M. Compounds 1-10 also presented strong alpha-glucosidase inhibitory activity. Of all tested compounds, compound 1 exhibited the strongest inhibitory activity, with an IC50 value of 0.58 mu M.