Hypolipidemic sesquiterpenoids with diverse structural skeletons from the medicinal fungus Irpex lacteus

Nine previously undescribed azulenoid-type sesquiterpenoids, including four common (1-4), four 5/6-cleaved (5–8), and one rearranged (9), were isolated from the edible-medicinal fungi Irpex lacteus. The structures of the compounds were established by combining spectroscopic methods, including integrated NMR, MS, and UV, as well as quantum ¹³C NMR and ECD calculations. All compounds exhibited a meaningful reduction in triglycerides activity. Notably, compounds 3, 5, and 6 displayed significant hypolipidemic activity, with EC₅₀ values of 43.8, 37.9, and 39.7 μmol/L, respectively. These values are comparable to the positive control, lovastatin, which exhibited an EC₅₀ of 37.6 μmol/L.