Pyrrolidine Alkaloids from Mangrove Fungus Penicillium sp. DM27 Enhance L6 Cell Glucose Uptake

Ten previously undescribed pyrrolidine alkaloids, namely penicipyrrolidines O–X (1–10), were isolated from the mangrove-derived fungus Penicillium sp. DM27, along with five known compounds (11–15). Their structures were determined by comprehensive analysis of HRESIMS and NMR spectroscopic data, and the absolute configurations were established based on biosynthetic considerations and TDDFT-ECD calculations. All isolates were evaluated for their glucose uptake capacity. Notably, penicipyrrolidine P (2) significantly enhanced cellular glucose uptake in L6 myotubes by 3.83-fold, demonstrating activity comparable to that of metformin, whereas penicipyrrolidines Q and R (3 and 4) showed relatively weaker effects.