Chemical characterization, antioxidant activity and activation of macrophages RAW264.7 via MAPK signaling pathway of the exopolysaccharide from Penicillium EF-2

BACKGROUND Microbial exopolysaccharides represent a significant source of polysaccharides, with their production unconstrained by temporal or spatial limitations. Penicillium , a filamentous fungus widely recognized for its medicinal food applications, is known to produce exopolysaccharides that exhibit cancer-inhibitory properties. RESULTS In the present study, exopolysaccharides from Penicillium EF-2 (EPS) were extracted and structurally characterized using ion chromatograph, infrared spectroscopy and NMR. The in vitro antioxidant and immunomodulatory activities were also investigated. EPS has a molecular weight of 111.47 kDa, is primarily composed of mannose, glucose and galactose, possesses a crystalline region, and exhibits excellent thermal properties. In free radical scavenging assays, EPS demonstrated robust in vitro antioxidant activity. Furthermore, EPS activated the mitogen-activated protein kinase pathway, enhancing the immunomodulatory capacity of macrophages. CONCLUSION EPS has excellent antioxidant and biological activities. The present study provides a theoretical basis for the utilization of EPS and offers new ideas for active sources of Penicillium fermented foods. © 2025 Society of Chemical Industry.