A Novel Antioxidant Isobenzofuranone Derivative from Fungus Cephalosporium sp.AL031

摘要

Bioassay-guided fractionation of metabolites from the fungus Cephalosporium sp.AL031 isolated from Sinarundinaria nitida led to the discovery of a new isobenzofuranone derivative, 4,6-dihydroxy-5-methoxy-7-methylphthalide (>1), together with three known compounds: 4,5,6-trihydroxy-7-methyl-1,3-dihydroisobenzofuran (>2), 4,6-dihydroxy-5-methoxy-7-methyl-1,3-dihydroisobenzofuran (>3) and 4,5,6-trihydroxy-7-methylphthalide (>4). The structure of the new compound >1 was determined based on MS, 1D and 2D NMR spectral data. Compounds >1–>4 showed potent antioxidant activity with EC50 values of 10, 7, 22 and 5 μM by 1,1-diphenyl-2-picryhydrazyl (DPPH) radical-scavenging assay.