Green Extraction and Liposomal Encapsulation of Inonotus obliquus (Chaga) Extracts: Comparative Phytochemical and...

Inonotus obliquus (Chaga) is a medicinal basidiomycete fungus with diverse bioactive compounds and pharmacological properties. This study systematically compared green extraction techniques: maceration, ultrasound-assisted extraction (UAE), and combined supercritical CO₂-pressurized liquid extraction (ScCO₂-PLE), using solvents of varying polarity (water, 50%, and 70% ethanol). Chaga extracts were analyzed for phytochemical composition (HPLC-Orbitrap Exploris 120) and antioxidant activity toward DPPH and hydroxyl (^•OH) radicals using EPR spectroscopy. The results revealed that both solvent polarity and extraction technique significantly influenced extraction efficiency and antioxidant potential. The UAE extraction method achieved the highest overall recovery of phenolic and triterpenoid compounds, with extracts obtained using 50% and 70% ethanol exhibiting the most pronounced and well-balanced radical scavenging activity (>98% toward DPPH, >91% toward ^•OH). Correlation and PCA analyses identified phenolic and triterpenoid compounds, including fungal-specific polyphenols such as hispidin and hispolon, as key contributors to antioxidant activity. Among the extracts obtained using different solvents, the extracts with the highest overall antioxidant potential were encapsulated into liposomes and evaluated for their DPPH and ^•OH radical scavenging. Encapsulation effectively preserved the antioxidant activity of ethanol-derived extracts, demonstrating that Chaga liposomes can maintain bioactivity while offering the advantages of controlled delivery. Combining optimized extraction with liposomal encapsulation thus represents a promising strategy to enhance the stability and practical applicability of Chaga antioxidants in nutraceutical or therapeutic contexts.