A new polyketide from <i>Penicillium</i> sp. HK-G2 and its inhibitory activity against α-glucosidase

A new polyketide derivative, pennafuredin (<b>1</b>), along with one known compound nafuredin (<b>2</b>), were isolated from <i>Penicillium</i> sp. HK-G2. The planar structure of pennafuredin (<b>1</b>) was characterised by comprehensive NMR spectroscopic analyses and HR-ESI-MS data. Its absolute configuration was elucidated by ML_<i>J</i>_DP4 probability analysis and ECD calculation. Pennafuredin (<b>1</b>) exhibited potent α-glucosidase inhibitory activity, with an inhibition rate of 83.97 ± 3.17% at a concentration of 1 mg/mL. Molecular docking analysis revealed that pennafuredin (<b>1</b>) displayed a superior binding affinity to α-glucosidase (-7.29 kcal/mol).