α-Glucosidase and Protein Tyrosine Phosphatase 1B Inhibitors from .

During a search for new α-glucosidase and protein tyrosine phosphatase 1B inhibitors from fungal sources, eight new secondary metabolites, including two anthranilic acid-derived peptides ( and ), four glycosylated anthraquinones (-), 4-isoprenylravenelin (), and a dimer of 5,8-dihydroxy-4-methoxy-α-tetralone (), along with four known compounds (-), were isolated from solid rice-based cultures of . The structural elucidation of these metabolites was performed using 1D and 2D NMR techniques and DFT-calculated chemical shifts. Compounds -, , and showed inhibitory activity to yeast α-glucosidase (αGHY), with IC values ranging from 57.4 to 261.3 μM (IC acarbose = 585.8 μM). The effect of (10.0 mg/kg) was corroborated using a sucrose tolerance test in normoglucemic mice. The most active compounds against PTP-1B were -, with IC values from 10.9 to 15.3 μM (IC ursolic acid = 27.8 μM). Docking analysis of the active compounds into the crystal structures of αGHY and PTP-1B predicted that all compounds bind to the catalytic domains of the enzymes. Together, these results showed that is a potential source of antidiabetic drug leads.