Pyridine Derivatives and Furan Derivatives Identified From the Medicinal Mushroom Irpex lacteus SY1002

Three new pyridine derivatives, irpelactedines A-C (1-3), and a new furan derivative, irpelactedine D (5), along with two structurally related known compounds, irpexidine A (4) and 5-carboxy-2-furanpropanoic acid (6), were isolated from the medicinal fungus Irpex lacteus SY1002. Their structures were elucidated through nuclear magnetic resonance and mass spectral analyses, combined with density functional theory calculations of electronic circular dichroism data. Evaluation of angiotensin-converting enzyme (ACE) inhibitory activity revealed that compounds 1 and 3 displayed moderate inhibition, with IC₅₀ values of 31.49 ± 3.41 and 80.96 ± 6.93 µg/mL, respectively. Molecular docking suggested that compound 1 is bound to the active site of ACE, leading to a reduction in its activity. Furthermore, cytotoxicity and antimicrobial activity tests revealed the low toxicity of these compounds. This is the first report on the ACE inhibitory activity of this class of pyridine derivatives, providing valuable insights into exploring the medicinal potential of I. lacteus and offering a structural template for developing new ACE inhibitors. Future efforts will focus on optimizing their structure and conducting in vivo testing to assess their therapeutic potential.