Erinacenones M-Y, Part 2: Thirteen New Isoindolinone Alkaloids with α-Glucosidase Inhibitory Activity from Liquid Cultures of the Edible and Medicinal Mushroom Hericium erinaceus.

As a continuation of our previous study on erinacenones A-L (Part 1), thirteen previously undescribed isoindolin-1-ones, erinacenones M-Y (1-13), were isolated from the fermentation broth of Hericium erinaceus. Their structures were elucidated by extensive spectroscopic analyses (1D and 2D NMR, HRESIMS), and the absolute configurations of 1-13 were determined by comparing their specific rotations with those of related phthalimidines (14-23). Compound 11 showed the highest α-glucosidase inhibitory activity among the tested compounds, with 31.5% inhibition at 50 μM. These findings significantly enrich the chemical diversity of isoindolinone metabolites from H. erinaceus and provide a foundation for future structure-activity relationship studies.